Korea Institute Of Construction Technology Research Articles

Utilizing text recognition for the defects extraction in sewers CCTV inspection videos

This paper proposed a novel automated framework for analyzing and tracking sewer inspection close-circuit television (CCTV) videos. The proposed model mainly supports the off-site examination and quality management process of the videos and enables efficient revaluation of CCTV videos to extract sewer condition data. The study discusses an important module for any automated analysis and defect detection in CCTV video. It includes two main modules: text recognition and cracks extraction. In the first module, multi-frame integration (MFI) was applied to reduce the background complexity, time and computational requirements needed for the video processing. Then maximally stable extremal regions (MSER) was used on the grayscale channel and HSV channel to effectively detect all the text edges. Saturation color channel was also applied to verify the detected text line and remove false alarms. In the second module, by utilizing the text information on each frame, the operator’s operation during the inspection is simulated which would indicate valuable clues about the location and severity of the cracks. The proposed methodology was validated using a set of video provided by the Korea Institute of Construction Technology.

Improvement of Uncertainty Assessment of Discharge Estimated by Velocity-Area Method

The present study was conducted to re-estimate the factors needed for the velocity-area method previously provided by ISO through precise actual scale experiments in order to verify the appropriateness of the errors of the individual factors presented by ISO 748 and ISO 1088. For this, a steady-state flow of a flow velocity of approximately 1 m/s, 7 m wide, and 1 m deep, was maintained in the mild slope channel located at the River Experiment Center (Andong) of the Korea Institute of Construction Technology. Under this condition, the objective was to measure the flow velocity very precisely with respect to the space by using a micro-ADV having a high accuracy of flow velocity measurement. The water depth was precisely measured before the generation of the flow by using Total Station. The ISO regulations and the results of the present experiment were applied to three different conditions. The uncertainty assessed by applying the results of the present experiment exceeded twice that of the uncertainty estimated by applying the uncertainty factors provided by ISO. The uncertainty of the lateral gap between measurement lines and the number of measurement points in the depth direction was dependent on the scale of rivers. However, ISO may have presented the uncertainty factors analyzed from the data obtained from a wide range of river scales. Therefore, the discharge estimated by the velocity-area method may be dependent on the scale of rivers. The errors of the individual factors of the velocity-area method derived from the present study may be applied to the estimation of the uncertainty of the discharge calculated by the velocity-area method in small rivers.

Hierarchically Structured Zinc Oxide Gas Sensors with Silver Catalyst

During the last few years, interest in wearable devices including a portable and wearable gas sensor system has increased. Since integration of fabric and gas sensors for a wearable breath monitoring system would allow continuous monitoring patients’ breathing gases such as acetone gas for diabetes (1), ammonia for renal disease (2), and ethanol for hepatic steatosis (3), realization of a miniaturized wearable gas sensor operating at daily environment is in demand. Zinc oxide has definite advantages over other semiconducting nano-scale metal oxides because of its electric properties such as wide bandgap and high electron mobility (4). ZnO nanostructures have been investigated such as nanorods, nanotubes, and nanowires. Recently, hollow micro/nanosphere ZnO has been attracting attention. It may be able to apply for dye-sensitized solar cells, photocatalts, high performance electrodes, and gas sensors due to its large surface-to-volume ratio and reduced transport lengths for both mass and charge transport (5). The researches about the catalytic decoration of ZnO gas sensors by metallic nanoparticles or layers have been also investigated to improve selectivity (6, 7). Especially, ZnO with silver is considered to exhibit relatively high sensitivity to ethanol (7). In this study, the hollow microsphere ZnO particles were prepared by a simple but new precipitation method and then Ag sputter coated. Electrophoretic deposition (EPD) of the hollow particles with Ag was then used to construct ZnO-Ag layers on flexible polyimide films. The structural properties of the deposited ZnO layers were analyzed by using SEM, TEM, and XRD. Then, gas sensing behaviors to detect ethanol, acetone, and ammonia by thickness of Ag are discussed in detail. This research was partially supported by the Korea Institute of Energy Technology Evaluation and Planning (20158520000210) grant funded by the Korea Government Ministry of Trade, Industry and Energy, a grant from a Strategic Research Project (2013-0132) funded by the Korea Institute of Construction Technology, and Auburn University IGP. (1) Zhang, Q., Wang, P., Li, J., and Gao, X. (2000) Biosens. Bioelectron. 15, 249-256 (2) Moorhead, K. T., Lee, D., Chase, J. G., Moot, A., Ledingham, K., Scotter, J., Allardyce, R., Senthilmohan, S., and Endre, Z. (2008) Computer methods and programs in biomedicine 89, 226-238 (3) de Lacy Costello, B., Ewen, R., Ratcliffe, N. M., and Richards, M. (2008) J. Breath Res. 2, 037017 (4) Ahn, H., Park, J.-H., Kim, S.-B., Jee, S. H., Yoon, Y. S., and Kim, D.-J. (2010) Electrochemical and Solid-State Letters 13, J125-J128 (5) Xie, Q., Li, J., Tian, Q., and Shi, R. (2012) Journal of Materials Chemistry 22, 13541-13547 (6) Lupan, O., Chow, L., Ono, L. K. Ono, Cuenya, B. R., Chai, G., Khallaf, H., Park, S., and Schulte, A. (2010) The Journal of Physical Chemistry C 114, 12401-12408 (7) Lyashkov, A. Yu, Tonkoshkur, A. S., Aguilar-Martinez, J. A. and Glot, A. B. (2013) Ceramics International 39, 2323-2330

Investigation of Silver Catalytic Properties on Reduced Graphene Oxide to Enhance Gas Sensitivity and Selectivity from Mixed VOC Gases

Volatile organic compounds (VOCs) that easily evaporate at room temperature have caused detrimental to respiratory, allergic, and/or immune effects in humans. Increased awareness of toxicity on these VOC gases has led many studies to focus on direct measurement of these harmful VOCs with high sensitivity at lower operating temperature. Gas sensors based on surface chemical reaction of semiconducting metal oxides are readily available commercially. To improve gas sensing performance with lowered operating temperature and high sensitivity, adequate catalysts are commonly used. However, there is still limit to lower sensing temperature of metal oxides to room temperature. It has been reported that graphene oxide (GO), a graphene sheet linked to oxygen functional groups, has potential to realize room temperature operation. Additional advantage of the GO includes large scale and low cost production for commercial application. In this study, GO thin films were deposited by drop coating and thermally reduced under Ar to eliminate the functional groups from GO films. The electrical properties of GO transformed from an insulator to semiconductor support GO to easily be activated for sensing gases. To enhance selective gas sensing at room temperature, many types of noble metals such as Pt and Au can be considered as an activators or sensitizers. We investigated GO with silver catalyst with relatively low cost. The formation of Ag island clusters driven by deposition conditions and their VOC gas sensing was characterized to find optimal condition of catalysts. The morphologies of silver catalyst decoated GO film were analyzed with SEM, TEM, and XRD, and the quantity of the silver catalyst was measured by EDS. Gas sensing response to VOCs was measured at room temperature to extract characteristic feature. In order to determine selective detection of specific VOC gas, 2 types and 5 types of mixed gases such as formaldehyde, benzene, styrene, toluene, and xylene were used. Detailed discussion on and the mechanism of silver catalytic effect on GO will be given. AcknowledgementThis research was partially supported by the Korea Institute of Energy Technology Evaluation and Planning (20158520000210) grant funded by the Korea Government Ministry of Trade, Industry and Energy, a grant from a Strategic Research Project (2013-0132) funded by the Korea Institute of Construction Technology, and Auburn University IGP.References Vlachos, D. S., C. A. Papadopoulos, and J. N. Avaritsiotis. "On the electronic interaction between additives and semiconducting oxide gas sensors." Applied physics letters 69.5 (1996): 650-652.Tyagi, Punit, et al. "Metal Oxide Catalyst assisted SnO2 thin film based SO2 gas sensor." Sensors and Actuators B: Chemical (2015).Ahn, Hosang, et al. "Volatile gas sensing properties of phase and composition gradient SnOx thin films by combinatorial sputter deposition." ECS Solid State Letters 2.1 (2013): P11-P13.Li, Yongjie, et al. "Catalytic performance of Pt nanoparticles on reduced graphene oxide for methanol electro-oxidation." Carbon 48.4 (2010): 1124-1130.Wang, Jianwei, et al. "Dielectrophoretic assembly of Pt nanoparticle-reduced graphene oxide nanohybrid for highly-sensitive multiple gas sensor." Sensors and Actuators B: Chemical 220 (2015): 755-761.Park, Hyejin, et al. "Transition of gas sensing behavior in non-reduced graphene oxides with thermal annealing." Materials Letters 136 (2014): 164-167.

Ethanol Gas Sensing Behavior of ZnO Nanorods Decorated with Various Metal Catalysts

Solid gas sensors are widely employed owing to their good stability and excellent gas responses [1]. However, the operating temperature to activate reaction sites of oxide semiconductor is relatively high to widen the applications [2]. As demands of gas sensors have increased in various fields, one of the research issues is to lower the operation temperature to enhance adaptability. To lower sensing temperature of semiconductor oxide sensors from several hundred Celsius to room temperature and to improve the gas selectivity, compositional gradient of catalysts was explored based on the catalyst effects on gas sensing mechanism and performance. Two metals having different catalytic activities were utilized: Platinum (Pt) and palladium (Pd). The thickness of the catalyst layer was kept constant, and only composition (ratio of the components) was changed to investigate the effect of the catalyst composites [3]. In this study, deposition of metal catalysts on ZnO NR gas sensing devices was successfully conducted by the sputter method. Pd and Pt were selected as catalysts to improve the gas sensing behaviors such as gas response, gas response rate, and selectivity. The amount of 1 or 2 % of catalysts was deposited on the gas sensing devices. When metal catalysts were applied, operation temperature of ZnO NR gas sensors was successfully reduced from 300 °C to 100 °C. Moreover, enhancement in gas sensing behaviors was observed with catalysts but degraded gas sensing behavior occurred with large amount of the catalysts. Improvement was resulting from the increase in activate sites and modification of the Fermi energy level. The degradation was primarily due to the blockage of activate sites caused by excessive amounts of catalysts. Catalysts decorated ZnO NR gas sensors can be a candidate for lowered operating temperature with great gas responses. This research was partially supported by the Korea Institute of Energy Technology Evaluation and Planning (20158520000210) grant funded by the Korea Government Ministry of Trade, Industry and Energy, a grant from a Strategic Research Project (2013-0132) funded by the Korea Institute of Construction Technology, and Auburn University IGP. [1] Azad, A. M., et al. Journal of the Electrochemical Society 139.12 (1992): 3690-3704.. [2] Morrison, S. Roy. Sensors and actuators 12.4 (1987): 425-440.. [3] Müller G, Friedberger A, Kreisl P, Ahlers S, Schulz O, Becker T. Thin Solid Films. 2003;436(1):34-45. Figure 1

광양지역에 적합한 항타강관말뚝의 목표신뢰성지수 및 저항계수 산정

최근 구조물 기초 분야에 대한 한계상태설계법이 국제적인 기술표준으로 요구됨에 따라 연구기반이 미약한 연약지반 개량공법에 대한 하중저항계수설계법 개발의 필요성이 대두되었다. 본 연구는 신뢰성 분석을 통해 항타강관말뚝의 목표신뢰성지수 및 저항계수를 산정하여 기초 구조물에 대한 LRFD code를 개발하고자 하였다. 프로그램의 검증을 위해 광양지역 16개의 항타말뚝 재하시험 결과와 2008년 한국건설기술연구원에서 이용된 57개의 항타말뚝 재하시험 결과를 취합하였다. 구조물기초설계기준에서 제안하고 있는 두가지 정역학적 설계공식에 대해서 대표 측정지지력과 설계지지력을 비교함으로써 저항편향계수를 평가하였고, 저항편향계수의 통계특성을 이용하여 일차신뢰도법 및 몬테카를로 실뮬레이션에 의한 신뢰성 분석을 실시하였다. 그 결과, 항타강관말뚝의 목표 신뢰성지수 2.0, 2.33, 2.5에 대해서 선단부 N치 50이하인 경우 두 지지력 공식의 저항계수는 각각 0.611~0.684, 0.821~0.537, 선단부 N치 50이상인 경우 각각 0.608~0.545, 0.749~0.643으로 제안되었다. 본 연구결과는 향후 다양한 기초구조물 및 지반구조물의 하중저항계수설계법 개발을 위한 자료로서 그 활용성이 있을 것이다. Recently, the necessity of developing the load and resistance factor design(LRFD) for soft ground improvement method has been raised, since the limit state design is requested as international technical standard for the foundation of structures. In this study, to develop LRFD codes for foundation structures in Korea, target reliability index and resistance factor for static bearing capacity of driven steel pipe piles were calibrated in the framework of reliability theory. The 16 data(in Gwangyang) and the 57 data(Korea Institute of Construction Technology, 2008) sets of static load test and soil property tests conducted in the whole domestic area were collected along with available subsurface investigation results. The resistance bias factors were evaluated for the tow static design methods by comparing the representative measured bearing capacities with the expected design values. Reliability analysis was performed by two types of advanced methods : the First Order Reliability Method (FORM), and the Monte Carlo Simulation (MCS) method using resistance bias factor statistics. As a result, when target reliability indices of the driven pipe pile were selected as 2.0, 2.33, 2.5, resistance factor of two design methods for SPT N at pile tip less than 50 were evaluated as 0.611~0.684, 0.537~0.821 respectively, and STP N at pile tip more than 50 were evaluated as 0.545~0.608, 0.643~0.749 respectively. The result from this research will be useful for developing various foundations and soil structures under LRFD.

Analysis of the Precision of International Inter-laboratory Round Robin Test Results of a Sandwich Panel Assessed According to ISO 13784-1 Standard

AbstrctSandwich panels were tested according to the ISO 13784-1 standard by the Fire Insurers Laboratories of Korea and the Korea Institute of Construction Technology in Korea, the Royal Institute of Technology in Sweden, and the Commonwealth Scientific and Industrial Research Organization in Australia. The tested sandwich panels consisted of steel sheets, expanded polystyrene, and glass wool and were supplied by the Fire Insurers Laboratories of Korea. The heat release rate results were collated and compared, and the variation in the data distribution was analyzed statistically. The precision of the maximum heat release rate (HRR) and that of the THR determined according to ISO 13784-1 was ± 10.16 kW and ± 37.00 MJ, respectively, suggesting suitable consistency of HRR and THR values among the participating institutions. The inter-laboratory comparison for the assessment of the same product according to the ISO 13784-1 standard was found to be feasible despite variations in the laboratory facilities, specifically in terms of the extraction hoods and calorimeter HRR capacity.

VOC Gas Sensors Fabricated with Graphene Oxide Composites for Food Safety and Quality

For food market, off-odors or flavors have become more than a quality issue with the increased awareness of food safety problems. This awareness to solve the safety problems, off-odor detection in foods, packaging materials, and their interactions involving scalping or other flavor system modification have been attracted. One of suggested methods is to use an electronic nose consisting of a gas sensor array to detect the volatile organic compounds (VOCs), released from foods as a byproduct of everyday physiological processes. Monitoring of the specific VOCs by a gas sensor can provide the information on both crop and field conditions. The array structure of gas sensors can enhance selectivity for in-situ detection [1, 2]. In this study, an array of sensors is investigated by employing graphene oxide and nanostructured metal oxide based on SnO2. Their composite films on a series of electrodes are prepared to create a high density of sensing array in a small size chip. A composition gradient sensing layers can produce unique gas response patterns. Figure 1 shows surface morphology of compositionally gradient tin oxides (1:6 ratio of GO to SnO2) and structure property confirmed by XRD result. The results on the growth of nanostructured films using solution process and vacuum process are presented. Figure 2 also shows sensing properties of the composites to formaldehyde gas at room temperature. The combinatorial structure enhances the sensing properties of devices in terms of sensitivity, selectivity and response rate. Additionally, such a sensor can meet the proposed idea, in-situ detection, and also the requirements for low-cost and high-volume production as well as high gas analytical performance. This research was partially supported by a grant from a Strategic Research Project (2013-0132) funded by the Korea Institute of Construction Technology, and Auburn University IGP. [1] A. D. Wilson and M. Baietto. Sensors. 2009, 9:5099-5148. [2] K. Arshak, E. Moore, G. M. Lyons, J. Harris, and S. Clifford. Sensor Review. 2004, 24(2):181-198. Figure 1

Combinatorial Structures of Graphene Oxide and SnO2 for Sensing various VOCs

Graphene (GR) and reduced graphene oxide (r-GO) are outstanding candidates for gas-sensing elements due to extremely high surface-to-volume ratio and excellent electrical properties [1]. Their unique and attractive properties can lead to novel sensors with minimum power consumption, room temperature sensing, and sensitivity. But limitations of slow reaction speed and recovery rate of the GR based sensors were observed [2]. The addition of metal oxide to make combinatorial structures with GR is being exploited as a potential way to overcome such limits The nanostructured metal oxides such as zinc oxide (ZnO) and tin oxide (SnO2) have been demonstrated as gas sensing materials with excellent semiconducting properties [3]. However, gas sensing of the metal oxide typically requires elevated temperatures, which causes energy consumption, and limits wide range of applications. Combination of GR/r-GO and metal oxide, especially SnO2, may present potential benefits by reducing energy consumption and enhancing response rate. Several approaches were attempted to make this combinatorial structure for gas sensing, but the approaches were mostly to utilize good electrical properties of r-GO. Few studies were conducted in applying non-treated graphene oxide (GO) for gas sensing. Since multilayer of GO has been demonstrated as good semiconducting materials [4], systematic approach to combine non-treated GO and metal oxide with changing the ratio as well as their combinatorial structures on gas sensing behaviors are investigated in this study. Combinatorial structures of GO and SnO2 were fabricated via electrophoretic deposition (EPD). The hierarchical oxide nanostructure of GO and SnO2 was analyzed by SEM and XRD as shown in Fig. 1. Mixture ratio was adjusted by adding different amount of SnO2 nanoparticles, and its effect on gas sensing behaviors was investigated. Fig. 2 shows the gas sensing behaviors of the GO/SnO2 composite films with 100 ppm of formaldehyde gas (HCHO). Gas sensing performance with non-treated GO and GO/SnO2mixture were demonstrated at room temperature. The strategies to construct combinatorial structure and their sensing behaviors in conjunction with sensing mechanisms are discussed in detail. This research was partially supported by a grant from a Strategic Research Project (2013-0132) funded by the Korea Institute of Construction Technology, and Auburn University IGP. [1] Lu, G., Ocola, L. E., & Chen, J. Applied Physics Letters, 94(8), 083111. (2009). [2] Dreyer, D. R., Park, S., Bielawski, C. W., & Ruoff, R. S. Chemical Society Reviews, 39(1), 228-240. (2010). [3] Park, H., Ahn, H., Chung, Y., Cho, S. B., Yoon, Y. S., & Kim, D. J. Materials Letters, 136, 164-167. (2014). [4] Wang, C., Yin, L., Zhang, L., Xiang, D., & Gao, R. 10(3), 2088-2106. (2010). Figure 1

Design of Network Architecture in Underground Structure Field Information Based on VI-GNSS

Recently, the integrated utilization of technology with IT is in demand for the effectiveness of field management together with the prevention and prompt action on safety accident at construction site. In addition, the establishment of construction site support system is necessary to implement the securing of worker's safety, smooth work instruction, efficiency in construction, and others. Data standardization and network architecture were designed regarding data and sound information for data transmission between systems and management. These were to construct USFSS based on integrated 2014년 10월 29일 접수 Received on October 29, 2014 / 2014년 12월 26일 수정 Revised on December 26, 2014 / 2015년 1월 5일 심사완료 Accepted on January 5, 2015 * 본 연구는 국토해양부 첨단도시개발 연구개발사업의 연구비 지원에 의해 수행되었음. 1 한국건설기술연구원 ICT융합연구실 ICT Convergence and Integration Research Division, Korea Institute of Construction Technology ※ Corresponding Author E-mail : wkddydrn@kict.re.kr VI-GNSS 지하구조물 현장정보 네트워크 아키텍쳐 설계 / 전흥수 · 장용구 · 오창균 · 김민관 65 VI-GNSS technology in this research. In the stability test of data for each system constructed through it, around 98% stability was secured between workers and for transfer vehicle system within underground structure and field server system in regards to the data transmission stability, around 100% stability was secured between field server system and control system, respectively. Also, in the sound transmission stability test, around 99% reliability could be secured with 1km distance as its standard in case of sound transmission from underground structure construction site to field office near the field through wireless FRS system.

기초의 크기효과에 관한 수치해석

Abstract Finite element analyses were conducted to investigate the size effect on the bearing capacity and settlementof shallow foundations, and the results were compared with those of theoretical equations. The calculated bearing capacity of the plate by numerical analysis and the theoretical equation was similar. Numerical analyses showed thatthe ultimate bearing capacity of strip footing on sand was affected by the size effect, whereas the ultimate bearingcapacity of strip footing on clay was not affected by the size effect. Numerical analyses showed that the square footing was unaffected by the size effect regardless of the type of foundation soil. In contrast to theoretical equations,settlement of the footing was affected by the size effect and was proportional to the footing width. Key Words : Size effect, Finite element analysis, Plate, Strip footing, Square footing * Corresponding Author : Jin-Tae Han(Korea Institute of Construction Technology)Tel: +82-31-910-0259 email: jimmyhan@kict.re.krReceived July, 29, 2014 Revised(1st September, 25, 2014, 2nd October, 1, 2014) Accepted January, 08, 2015

고온에 노출된 초고강도 콘크리트의 압축특성

최근의 건축 구조물이 고층화, 대형화됨에 따라 초고강도 콘크리트의 적용 및 수요가 증가하고 있는 추세이나, 화재에 대한 취약성을 가지고 있는 초고강도 콘크리트의 열적 특성에 대한 검토는 아직 충분하지 않으며 이에 대한 성능 검토 또한 요구되고 있는 실정이다. 이에 이 논문에서는 초고강도 콘크리트의 고온 재료 모델 개발에 대한 기초적 자료를 제공하기 위하여 상온에서 800℃까지의 고온 가열을 받은 100 MPa급 초고강도 콘크리트를 대상으로 가열온도의 변화에 따른 잔존압축강도, 탄성계수 및 응력-변형 성상, 반복하중 시의 응력-변형 성상 등 역학적 특성 변화를 확인하였다. 또한, TG/DTA분석과 SEM 촬영으로 콘크리트의 화학?물리적 특성을 확인하고 국내?외의 기존 연구와 비교?검토하였다. 그 결과, 가열온도 300℃에서 잔존압축강도 및 탄성계수의 급격한 저하를 확인하였으며, 반복하중 하에서는 가열온도 400℃부터 소성거동이 발생하는 것과 함께 단일하중과 거의 동일한 경향을 보임을 확인할 수 있었다. TG/DTA 분석 및 SEM 촬영을 실시한 결과와 기존 연구를 비교?검토한 결과, 콘크리트 내부 조직의 열화와 수분 증발 및 화학반응 등으로 인하여 잔존압축강도 및 탄성계수의 저하가 일어났음을 확인할 수 있었다.

Gas Sensing Behaviors of Combinatorial Structures of Graphene Oxide and ZnO

Nanoscale materials are outstanding candidates for gas-sensing elements due to extremely high surface-to-volume ratio [1]. Their unique and attractive properties can lead to novel sensors that have advantages of fast reaction speed and sensitivity, ease of miniaturization, minimum power consumption, and low cost. Recently, the expansion of gas sensor applications to medical diagnosis, wearable electronics would demand operation at room temperature and convenient fabrication of the sensors on various substrates [2].Nanostructured metal oxides such as tin oxide, zinc oxide, and graphene oxide have been demonstrated as gas sensing materials with their excellent semiconducting properties. However, the sensitivity and selectivity of the metal oxide-based gas sensors may not be sufficient for a wide range of applications. To overcome the limitations, combined graphene oxide and ZnO based sensor has been attempted by making ZnO as catalyst nanoparticles [3,4]. Such hybrid structure may present potential benefits, but the methods to construct combined structure of graphene oxide and ZnO are rarely found in the literature. Therefore, we investigate the design and fabrication of the combinatorial structure from two nanomaterials of graphene oxide and ZnO.Combinatorial structures of graphene oxide and ZnO have been performed via chemical and physical deposition methods to form layer by layer structure. Hierarchical oxide nanostructures consisting of graphene oxide flakes and ZnO nanorods were also fabricated by using electrochemical deposition. Gas sensing performance of individual graphene oxides and ZnO nanorods was shown in Fig. 1. Graphene oxide can sense various gases at room temperature, but ZnO nanorods can perform at room temperature with an aid of external energy such as UV. Thus chemical modification of ZnO nanorods was performed to achieve room temperature operation. It was also found that sensing performance of graphene oxide was strongly dependent on surface conditions or reduction of graphene oxide. Thermal reduction of deposited graphene oxide resulted in the change of reduction degree. The increase of thermal reduction temperature enabled transformation from graphene oxide (GO) to reduced graphene oxide (r-GO) as confirmed by FTIR and Raman in Fig.2. Such change also showed n-p transition of sensing behaviors. This study will present systematic investigation of nanostructured graphene oxide and ZnO for combinatorial structure. The strategies to construct combinatorial structures and their sensing behaviors in conjunction with sensing mechanisms are discussed in detail.This research was supported by Agency for Defense Development (ADD) as global corporative research for direct urine fuel cell and a grant from a Strategic Research Project (2013-0132) funded by the Korea Institute of Construction Technology.[1] S. Basu and P. Bhattacharyya, Sensors and Actuators B: Chemical(2012).[2] Q. Zhang, P. Wang, J. Li and X. Gao, Biosensors and Bioelectronics, 15, 249 (2000).[3] G. Singh, A. Choudhary, D. Haranath, A. G. Joshi, N. Singh, S. Singh and R. Pasricha, Carbon, 50, 385 (2012).[4] T. V. Cuong, V. H. Pham, J. S. Chung, E. W. Shin, D. H. Yoo, S. H. Hahn, J. S. Huh, G. H. Rue, E. J. Kim and S. H. Hur, Materials Letters, 64, 2479 (2010).

다중 위성 강우자료를 이용한 유출 평가

본 연구는 전지구 위성 강우자료와 글로벌 지형자료를 이용하여 유출분석을 수행하여 계측자료가 부족한 지역에 대한 강우-유출 관계를 파악할 수 있는 방법을 제시하는 것을 목적으로 하였다. 사용된 위성 강우자료는 CMORPH와 GSMaP_NRT자료를 사용하였고, 글로벌 지형자료는 GTOPO30 및 GLCC자료를 이용하였다. 유출분석을 위한 도구는 IFAS를 이용하였다. 강우 정확도 평가에서 관측강우자료와의 상관계수는 CMORPH 및 GSMaP_NRT에서 0.37 및 0.30로 분석되었다. IFAS를 이용한 유출분석에서 매개변수를 보정하지 않은 경우에도 위성 강우자료를 이용한 모의 첨두유출량이 관측유출량과의 상대오차가 낮았다. 따라서 계측자료가 없는 유역에서의 적용성이 있는 것으로 사료된다. 향후 대표적인 비접근 지역인 북한지역에 대하여 위성강우 및 글로벌 지형자료를 이용하여 유출분석에 활용할 계획이다. The objective of this study is to suggest a method for estimating rainfall-runoff relationship using runoff analysis with satellite rainfall and global geographic data for the region due to lack of observed data. This study uses CMORPH and GSMaP_NRT as satellite rainfall data, and GTOPO30 and GLCC as global geographic data. IFAS is used for runoff modeling. In the evaluation of rainfall data, the correlation coefficients of CMORPH and GSMaP_NRT with observed data are 0.37 and 0.30 respectively. Calculated peak runoffs using IFAS show small relative errors with observed data in case of parameters are not calibrated with satellite rainfall data. Therefore, the methods suggested in this study could be applied to ungauged watershed. In the future, this study will analyze runoff for North Korea, a representative inaccessible region, using satellite rainfall and global geographic data.

백두산 화산재해대응시스템 개발방안 연구

The Korea had been known as a safe region in volcanic disaster. However, precursor phenomena for volcanic eruption in mountain Baekdu have been frequently reported in these days. Therefore, the number of volcano experts, who warn the volcanic eruption in the Korean peninsula, has been increased. This paper describes the plan for developing volcanic disaster response system for mountain Baekdu. First, disaster prevention business system of National Emergency Management 2013년 12월 5일 접수 Received on December 5, 2013 / 2013년 12월 19일 수정 Revised on December 19, 2013 / 2014년 3월 17일 심사완료 Accepted on March 17, 2014 * 본 연구는 소방방재청의 백두산화산대응기술개발사업인 '화산재해 대응시스템 개발' [NEMA-백두산-2012-3-2]과제의 지원으로 이루어졌음. 1 한국건설기술연구원 ICT융합연구실 ICT Convergence and Integration Research Division, Korea Institute of Construction Technology ※ Corresponding Author E-mail : kth@kict.re.kr A Study on the IT-Based Response System Development for Mt. Baekdu Volcanic Disaster 14 FIGURE 1. Mt. Baekdu and volcanic terrain of Korea Agency(NEMA) and related IT-based systems are analyzed. Second, business processes for volcanic disaster response are derived based on the business system. Third, The system architectures are designed referred to related disaster response system, and required spatial information is investigated. Finally, we implement the pilot system to test the suggested volcanic disaster response system. Applying suggested volcanic disaster response system to NEMA, additional test and system supplementation should be carried out. We expect that the complete volcanic disaster response system, which will be implemented based on this research, will minimize the volcanic disaster damage in the area of Korea, China, and Japan.

CAT 모형을 이용한 울산지역 주요 하천유역의 물순환 분석

본 연구는 태화강을 비롯한 동천, 회야강 및 청량천 등 울산의 주요 하천유역을 대상으로 최근 한국건설기술연구원이 개발한 CAT모형을 이용하여 물순환 분석을 실시하였다. CAT모형의 적용을 위해 태화강은 25개, 동천은 11개, 회야강은 17개 그리고 청량천은 5개의 소유역으로 분할하여 유출기여유역과 함양유역으로 구분하는 개념을 적용하였다. 대상유역에서 1975년도와 2008년에 실측된 강우량과 토지이용도 변화 등의 수문자료를 이용하여 물순환 분석을 실시한 결과, 4개 하천유역 모두에서 도시화에 따른 불투수 면적의 증가로 인해 표면유출은 중가하고 중간유출은 감소하는 것으로 나타났다. 태화강과 태화강의 지천인 동천유역의 표면유출 증가는 1.7%와 2.4%로서 비교적 적고, 회야강과 청량천은 3.2%와 7.7%로 증가폭이 큰 것은 유역의 개발에 따른 도시화율 증가의 정도를 잘 반영하는 것으로 분석되었다. This study aimed to analyze water cycle at Taehwa river, Dongcheon, Hoiya river and Cheongryang cheon in Ulsan city using CAT model developed by Korea Institute of construction technology. To apply CAT model, we separated Teahwa river into 25, Dongcheon into 11, Hoiya river into 17 and Cheongryangcheon into 5 subbasins and discriminated between contribution runoff basins and source basins. The results of water cycle analysis performed using rainfall datas measured from 1975 and 2008 and hydrologic datas of change of land use etc. were that surface runoff increase and interflow decrease, caused by the increase of impervious area. The increases of surface runoff at the basin of Taehwa river and Dongcheon which is a tributary of Taehwa river were small and similar to each other respectively as 1.7% and 2.4%, and increased high rate of 3.2% and 7.7% in Hoiya river and Cheongryangcheon including subbasins which are having high rate of urbanization.

A Compensation Method and Comparative Analysis of Historical Unit Price Considering Work Types for Large and Small-Scale Projects

Recent historical unit price is presented by the Korea Institute of Construction Technology (KICT) and it is analyzed by data from large-scale projects. Therefore it has problem applying to small-scale projects. To indicate the problem, the study compared historical unit price of large-case project and small-case project in the case of civil engineering work, building construction, and mechanical facility work. As a result, average historical unit price of small-scale project was 26.6% higher than large-scale project. On the other hand, difference on the labor cost was 18.4%, difference on material cost and overheads were 8.18%. Moreover, the study proposed compensation method to correct to apply recent historical unit price to small-scale project.

공간데이터 LOD 기반 3차원 대용량 객체의 경량화 알고리즘 연구

Abstract Recently, Construction information is being changed from CAD to BIM, and GIS is extending from outdoor to indoor information. In these circumstances, the needs of continuous use of construction information linked with GIS are growing constantly in stages of maintenance, operation and service as well as planning, design and construction. To this end, it is essential element to represent 3-dimensional large object efficiently in establishing BIM-GIS interoperability platform by combination of construction and spatial information. In this study, we design spatial data LOD for making spatial object and texture by level, and develop weight lightening algorithm of large spatial object.Keywords :Spatial data, LOD, 3-Dimensional Large Object, Weight Lightening † *** This research was supported by a grant from a Strategic Research Project (Development of Conver gence Technology on Construction & Spatial Information based on BIM/GIS Interoperability) fun ded by the Korea Institute of Construction TechnologyJoon Yeop Na, Senior Researcher, Korea Institute of Construction Technology. naz@kict.re.krChang Hee Hong, Senior Researcher, Korea Institute of Construction Technology. chhong@kict.re.kr (Corresponding author)

LiDAR 고도자료와 LISFLOOD 모형을 이용한 홍수범람해석

Great loss of life and property has been occurred by the severe flood globally. In Korea, a flood inundation map is used as one of the non-structural measures for reducing flood damage, and various inundation models have been studied for flood inundation analysis. This study applies LiDAR data and LISFLOOD model for flood inundation analysis and discusses the the modeling results from levee breaching 2013년 8월 14일 접수 Received on August 14, 2013 / 2013년 9월 16일 수정 Revised on September 16, 2013 / 2013년 10월 7일 심사완료 Accepted on October 7, 2013 * 본 연구는 한국건설기술연구원 13주요-시드사업(과제명-지방하천 홍수위험지도 제작기술 개발)의 연구비지원에 의해 수행되었음. 1 한국건설기술연구원 수자원연구실 Water Resources Research Division, Korea Institute of Construction Technology ※ Corresponding Author E-mail : ckchoi@kict.re.kr Analysis of Flood Inundation Using LiDAR and LISFLOOD Model 2 scenarios for evaluating the applicability of the model to stream inundation modeling. In the results of LISFLOOD modeling, maximum inundation area was similar to the inundation map by HEC-RAS model just less than 4%. The inundation area by each levee breaching scenario showed the difference from 0.2% to 6.5%. Inundation processes were different each other according to the position of levee breach point, and maximum inundation area and depth were changed by the flow direction of stream and flood plain. This study shows that LISFLOOD model can be applied properly to stream inundation analysis using various inundation scenarios.

영국의 설계홍수량 산정모형인 FEH-ReFH의 국내 남천유역 적용성 평가

ABSTRACT The purpose of this study is to evaluate the applicability of UK design flood estimation model, FEH-ReFH through rainfall-runoff simulation of Korean watershed. For the Nam stream watershed(165.12㎢), the model was calibrated using 6 storm events. The watershed and hydrological characteristics for the model requirements was prepared by developing input data pre-processors based on open GIS. The parameters of rainfall loss rate and unit hydrograph were calibrated from the observed data. The results can be used for improving and standardizing the Korean design flood estimation method. 2013년 6월 6일 접수 Received on June 6, 2013 / 2013년 8월 19일 수정 Revised on August 19, 2013 / 2013년 9월 3일 심사완료 Accepted on September 3, 2013* 본 연구는 국토교통부 물관리연구사업의 연구비지원(11기술혁신C06)에 의해 수행되었음.1 건국대학교 사회환경시스템공학과 Dept. of Civil & Environmental Systems Engineering, Konkuk University2 한국건설기술연구원 수자원연구실 Water Resources Research Division, Korea Institute of Construction Technology※ Corresponding Author E-Mail : kimsj@konkuk.ac.kr