Installation Environment Research Articles

CFRPを利用した落雷誘導特性に及ぼす風車設置環境の影響

CFRPを利用した落雷誘導特性に及ぼす風車設置環境の影響

A Sense of Ambient Entrapment in Hito Steyerl’s Factory of the Sun

This article proposes the notion of ambient entrapment to conceptualize the affective experience of surveillance in the current age of ubiquitous computing and smart technologies. A sense of ambient entrapment is identified as a vague, yet pervasive feeling of a controlled environment saturated by surveillance and exploitation, where machine perception and algorithmic processes are hard at work. Arguing that artworks are particularly adept at expressing affective experiences and emerging cultural feelings of surveillance, the article offers a reading of German artist Hito Steyerl’s immersive video installation environment Factory of the Sun (2015) to further explore the theoretical argument. Inside the dark installation space, visitors are immersed in a blue LED grid environment and encouraged to recline in beach chairs facing a large screen. What is perceptible as time passes inside Factory of the Sun, the paper argues, is an indefinable yet all-encompassing sense of something working and conditioning in the background, of technologies extracting and exploiting personal data while we, at the same time, desire and feel the lure of said technologies and devices. The article concludes that artworks can make us aware of the often invisible and barely perceptible forces at work in our environments and everyday life and suggests we should turn to contemporary art as sites of knowledge of the affective experience of ambient surveillance.

Development of ventilation and sound insulation materials by the multi-objective optimization

Natural ventilation-based houses in tropical countries often suffer from poor acoustic performance. To address this issue, we developed ventilation and sound-absorbing materials using a multi-objective optimization program. The program was developed to design test specimens that optimize the sum of the flow velocities of all elements of the divided cylindrical 3D model for sound-absorbing ability and the sum of the flow velocities in the bottom elements of the model for ventilation ability, with the objective of maximizing both. By outputting the specimens using a 3D printer, we were able to select materials suitable for the installation environment without requiring individual design changes. In this report, we focus on improving the sound insulation rate by refining the objective functions used to create the specimens. We measured the transmission loss using a self-made impedance tube and the 4mic method and verified the validity of our programming results by comparing them with those of laboratory experiments. Our approach has the potential to improve the acoustic performance of natural ventilation-based houses in tropical countries, making them more comfortable and conducive to living and working.

Evaluation of the impact of installation environment for a condensing unit of a split-type air conditioner in a plant room of Korean apartment dwellings

In many countries, split-type air conditioners have been widely used in residential buildings due to the high energy efficiency. It has been reported that optimal heat exchange conditions are necessary for the condensing unit of the air source air conditioner to perform at its rated level, particularly when installed in an apartment building's plant room. This study analyzes the impact of installation parameters of a condensing unit of a split-type air conditioner, such as the clearance distance from the rear surface of the condensing unit, the louver angle, and the use of insect screen or air-guide, on the cooling performance. The findings from the experiments and the correlations between parameters and input power presented in this paper would be useful in designing residential buildings with split-type air conditioners and air conditioner plant rooms for optimal cooling performance.

Evaluation of Air Quality inside Self-Contained Breathing Apparatus Used by Firefighters

(1) Background: When a fire breaks out, combustibles are burned and toxic substances such as carbon monoxide (CO), polycyclic aromatic hydrocarbons (PAH), benzene, and hydrogen cyanide are produced. The purpose of this study is to evaluate the air quality inside self-contained breathing apparatus (SCBA) by comparing it to that in the environment where the SCBA charger is installed. (2) Methods: The design of this study was a simulation-based case-control experiment study, and the experiment was conducted at two fire stations located on land and on water. When charging the SCBA, it was differentiated according to the presence or absence of exposure to harmful substances and the degree of exposure. The air quality inside the SCBA in the charging room installed in the fire station garages located on land and in the water, which were not completely isolated from harmful substances, was evaluated. CO, carbon dioxide (CO2), water, and oil mist were measured and analyzed to determine the air quality inside the SCBA. (3) Results: In the case of land firefighting stations, the mean CO among the SCBA internal air quality items was 20 times higher than the outside the SCBA, and higher than the safe range in the group with the highest exposure at the sites of firefighting buildings completely isolated from hazardous substances. The CO levels of all items of water were analyzed to be higher than the safe range in the floating fire station. (4) Conclusions: It was confirmed that the installation environment of an SCBA charging room can affect the safety of the charged internal air quality components. The results of this study can be actively used for the operation and management of SCBA charging room environments when building firefighting buildings in the future for the hygiene, safety, and health of firefighters.

Monitoring for relative effect of corrosive environmental factor on corrosion rate for steel structural details

It is necessary to examine the corrosion durability of a steel structure based on its local corrosive environmental conditions since its corrosion deterioration could appear locally, depending on the installation environment or structural details. In this study, therefore, test specimens with various structural details were fabricated to evaluate the relationship between the corrosive environmental factors and relative corrosion rates, and outdoor exposure tests were conducted on the distinguishing area with and without airborne chloride. For this, the temperature, relative humidity, corrosion current, time of wetness (TOW), and surface chloride were measured as corrosive environmental factors for the outdoor exposure test site and test specimens, and their relative corrosion rates were also examined using monitoring steel plates (MSP) as their mean corrosion depths. From the outdoor exposure test results, their mean corrosion depths exposed to the same environment were shown to be affected by their angles of the structural details. The relative mean corrosion depth varying due to the structural details was shown to be affected by the TOW and surface chloride.

Technical analysis on airworthiness compliance of lighting components for civil aircraft emergency evacuation slides

The emergency landing safety of emergency evacuation slides can be improved greatly by using lighting components, especially in dark environments. To design a required lighting system, two problems need to be solved, which are also the focus of this paper. Firstly, what airworthiness compliance work should be planned and how to do it. Secondly, how to design to meet the airworthiness requirements should be considered. A complete and effective airworthiness compliance method was proposed by analyzing various performance characteristics such as self-opening function, lighting duration, illuminance, and installation environment. Airworthiness requirements are decomposed into design features, and the design requirements of lighting components are put forward. This study can provide verification methods and design ideas for the lighting components of civil aircraft emergency evacuation slides.

Simulation Analysis of Tooth Break Faults of Gear Transmission System based on Electromagnetic Torque Signal

The traditional gear fault simulation model focuses on the vibration signal. However, the vibration sensor is not easy to install, and the vibration signal is easily affected by the installation location and environment of the vibration sensor. The motor itself has the characteristic of sensor. But in the traditional integrated model of motor and gear, the gear model is established based on the dynamical equation of the gear. However, the gear transmission established by the dynamics of the gear can’t fully reflect the running state of the gear. Moreover, the more complex the gear transmission system, the more complex and inaccurate the dynamical equation will be. Based on the above situation, in this paper, the virtual prototype model of the two-stage gear transmission system with broken tooth fault in different parts of the gear is established in Adams, which is imported into Matlab and co-simulated with the motor control model built in Matlab. Then the electromagnetic torque signal is analyzed. The results show that different characteristic frequencies of gear faults can be detected in the electromagnetic torque signal. The virtual prototype model of gear transmission system can accurately reflect the motion state of gear, and the fault of the complex gear transmission system can be simulated.

Piezo-Transmissive Structure Using a Multi-layered Heterogeneous Film for Optical Transmittance Modulation.

As the damage caused by the recent climate crisis increases, efforts are being made to develop low-power and high-efficiency technologies to reduce pollution for energy production worldwide. Among them, research on the mechano-responsive optical transmittance modulation technology is being actively conducted as it can be applied to various application fields for reducing energy consumption: low-power sensors and smart windows. The piezo-transmittance structure, which is one of the optical transmittance modulation structures, has fewer constraints on the installation environment; therefore, many applications have been proposed. However, it is still challenging to fabricate a piezo-transmittance structure with a large-area production, high throughput, and good tunability because of complex curing and dissolution processes. Herein, we present an efficient fabrication method for a multi-layered piezo-transmittance structure using a large-area abrasive mold and thermal imprinting process. The piezo-transmittance performance (e.g., sensitivity and relative change of transmittance) shows temperature/humidity-independent characteristics and can be designed by tuning design parameters such as the number of layers, abrasive grade, and film material. Also, the surrogate model of the performance obtained from the Monte Carlo simulation and prediction model can offer tunability for various applications. Finally, we demonstrated two energy-efficient applications: the smart window integrated with a hydraulic pump showed high thermal efficiency in indoor environment control, and the telemetry system was demonstrated to measure pressure remotely.

태양광 연계 에너지저장장치 내부 환경 특성 분석

This paper analyzed internal environmental impact of energy storage device facilities connected to the photovoltaic power generation system. The use of energy storage system is increasing for demanding in new renewable energy (photovoltaic power, wind power, etc.) and adjusting frequency regulation(FR) in system operation.BRSince fires are concentrated in energy storage systems for connection with renewable energy, it is necessary to find the cause of the fire through analysis of the on-site installation environment and operation. This paper analyzes the internal environmental characteristics of energy storage systems connected to photovoltaic power generation and proposes a safety plan.

공통 모드 전압 및 THD를 고려한 계통연계형 3레벨 NPC 인버터의 운용 알고리즘 연구

A grid-connected 3-level NPC inverter is a power conversion device that connects renewable energy generators, such as photovoltaic or wind turbines to the grid. Although many studies have focused on this inverter, commercializing it requires strictly satisfying various safety and power quality-related standards. Among many standards, leakage current and grid current total harmonic distortion(THD) can be affected by external factors such as installation environment, aging, and grid conditions. Hence, inverter operations that can satisfy these standards need to be explored. In this study a 3-level NPC inverter operation algorithm using the Phase Opposition Disposition-PWM method that can effectively reduce leakage current and switching frequency adjustment to reduce THD effectively has been proposed.

Photovoltaic Module Degradation Forecast Models for Onshore and Offshore Floating Systems

The degradation trend of photovoltaic modules depends on the technology, manufacturing techniques and climatic conditions of the site where they are installed. Longer useful life of the PV modules means that they will be able to produce much more energy than was used to build them; thus, extending the useful life of the modules is beneficial for the environment and increases the cost effectiveness of PVs. The problem of land use has prompted the development of agrivoltaic systems to exploit the same land both for the production of energy and for agriculture, and on water surfaces such as lakes and dams (floating PV). The exploitation of floating PV systems in onshore and offshore areas is currently under study. This constitutes an opportunity for which many factors must be taken into account; a fundamental aspect is the environmental impact, on which some recent studies have focused. Another aspect is the impact of the marine environment on PV system reliability and durability, due to the stress on operating conditions. The aim of this preliminary study is to evaluate the influence of the marine environment on the degradation trend of photovoltaic modules, based on existing models whose inputs are meteorological data from offshore locations. The results obtained from the application of a cumulative exposure model unexpectedly showed a lower degradation value in the offshore environment than on the mainland: −0.95% and −3% values of power decay, respectively. The absolute value of power decay in the onshore case is higher than the typical values because the used model has to be revised, as the empirical coefficients of the model have to be calculated according to the installation environment. The empirical coefficients used in the model were obtained in environmental conditions different from those under study. In the offshore case, the degradation estimated by the model does not take into account some environmental factors typical of the marine environment. Model adaptations calibrated with datasets of plants in environmental conditions similar to those analyzed would allow for greater accuracy in the results.

Effects of Quantity and Arrangement of a Flame-Retardant Cable on Burning Characteristics in Open and Compartment Environments

The results of cable burning experiments conducted in a well-controlled or open environment may differ from fire phenomena in an actual installation environment of cables where the effects of ventilation conditions and thermal feedback exist. In order to prevent the misunderstanding of fire phenomena due to these differences, the changes in burning characteristics in open and compartment environments were investigated for a flame-retardant (TFR-8) cable and general PVC (VCTF) cable arranged on three-layer trays. As a result, it was confirmed that the fire scale, fire spread area, and cable damage varied greatly depending on the cable arrangement under the same cable quantity condition. Furthermore, the maximum heat release rate (HRR) and fire growth rate of TFR-8 in the compartment environment increased more than 3-times compared to the open environment, and showed a similar level of fire risk to VCTF even though it is a flame-retardant cable. Additional experiments using vertical and horizontal openings of various shapes were conducted to evaluate the individual contributions of thermal feedbacks from the wall and smoke layer to the changes in burning characteristics within the compartment. The results of this study can be used as basic data to reduce fire damage while providing an essential understanding of cable fire phenomena.

Fast Segmentation Method of Sonar Images for Jacket Installation Environment

It has remained a hard nut for years to segment sonar images of jacket installation environment, most of which are noisy images with inevitable blur after noise reduction. For the purpose of solutions to this problem, a fast segmentation algorithm is proposed on the basis of the gray value characteristics of sonar images. This algorithm is endowed with the advantage in no need of segmentation thresholds. To realize this goal, we follow the undermentioned steps: first, calculate the gray matrix of the fuzzy image background. After adjusting the gray value, the image is divided into three regions: background region, buffer region and target regions. After filtering, we reset the pixels with gray value lower than 255 to binarize images and eliminate most artifacts. Finally, the remaining noise is removed by morphological processing. The simulation results of several sonar images show that the algorithm can segment the fuzzy sonar images quickly and effectively. Thus, the stable and feasible method is testified.

What EV users say about policy efficacy: Evidence from Shanghai

Sustainable EV adoption is critical to urban low-carbon future. The in-depth analysis of urban incentives' role in encouraging EV purchases is less examined. The perspectives of EV adopters can provide unique insights into policy implementation and effectiveness, informing future policy design and learning. Taking Shanghai—a city with roughly 4% of global EV stock—as the case, we aim to fill the above gaps via an online survey among existing EV owners. Our analysis shows that (a) urban EV strategies played a critical role in Shanghai's early adoption success, encouraging many first-time buyers to choose EVs over petrol cars, avoiding future lock-in emissions; (b) locally tailored measures such as free license plates and access to highways during rush hours significantly encouraged EV purchases; and (c) users' feedback on policy implementation reveals challenges for next-step scale adoption, especially regarding an unsupportive installation environment for private chargers, and inadequate services, e.g., infrastructure maintenance and the building up of a used-car market. These findings suggest city-level incentives can increase EV uptake but are insufficient to support a complete EV transition. Research needs to look beyond incentives for early adopters and into policy and social aspects that can support upscaling and social embedding of EVs.

Evaluating the effect of aging on adhesion for hot-poured road sealants through a modified adhesion test

• A new modified adhesion test by considering cyclic temperature effect is proposed. • The cyclic temperature effect is simulated through 3 hot-cold cycles. • The total dissipated energy is proposed to evaluate the effect of aging on sealant adhesion. Due to the influences of installation and field environment, the adhesion failure usually occurs during the actual application of sealants. But current specification methods do not adequately consider the installation aging and field cyclic temperature effect on the adhesion of sealants. Hence, a new modified adhesion test method was proposed to quantitatively evaluate the effect of aging on the adhesion of three types of sealants. The cyclic temperature effect was simulated through 3 hot-cold cycles and the aging during installation was modelled through the short-term thermal aging. Based on the modified adhesion test, an evaluation method and 3 evaluation indexes were proposed to quantitatively evaluate the adhesion of sealants. Further, based on energy method, total dissipated energy ( E t ) was proposed and used to quantitatively evaluate the effect of aging on sealant adhesion. Then the aging indexes of several evaluation indexes were proposed to analyze the effect of aging on the adhesion of sealants. Finally, a comparison was made between current specification bond test and the modified adhesion test and the advantages of modified adhesion test were demonstrated. The results show that short-term aging had a significant weakening effect on the maximum tensile stress ( σ n ) and made the tensile separation stiffness ( K n ) of different sealants change irregularly. The conventional adhesion evaluation index, growth rate of tensile separation stiffness ( G s ), is not suitable for evaluating the effect of aging on sealant adhesion. Compared to G s , the E t index reflects the accumulation of dissipated energy during the whole test process, and improves the stability of the overall evaluation. The evaluation index E t and the corresponding aging index AI E were recommend to quantitatively evaluate the effect of aging on sealant adhesion. Due to the effect of short-term aging, the adhesion of three types of sealants under the cyclic temperature effect decreases by 15%∼35%. One recommend that the effect of short-term aging should be considered in the adhesion evaluation of sealants.

Online shock sensing for rotary machinery using encoder signal

With the increasing of equipment interaction in the industry 4.0 era, the accidental shocks are inevitable during the device operation, resulting in a decline in equipment safety and product quality. Hence, it is very essential to sense external shock to ensure safety and stability. However, shock sensing by adding external sensors is not desirable due to costs and limitation of installation environment. Moreover, shock sensing in an online manner is also a challenge. In view of these bottlenecks, a framework of shock sensing for rotating machinery using encoder signal is constructed in this paper. We first investigated the feasibility and challenges of this framework. To capture the weak feature introduced by shock in encoder signal, a rank-estimated online RPCA method is proposed. Finally, static testing confirms that shock sensing can be effectively achieved using encoder signal without any additional sensors. On this basis, the results of dynamic testing further demonstrate that the proposed scheme is able to sense the external shock under different operating conditions, which is expected to provide a new idea for intelligent perception of rotating machinery.

Studies of defect states and kinetic parameters of car windscreen for thermoluminescence retrospective dosimetry

In case of any natural disasters or technical failures of nuclear facilities, the surrounding media including human beings may receive unexpected radiation exposures. In such a situation, there is no viable way to know how much radiation dose is received by human beings. Realizing that motorized vehicles are parked at fixed but increasing distances within the nuclear installation and industrial environment, this study investigates the kinetic parameters of readily available car windscreens which form the basis to be employed in post-accident dose reconstruction or for retrospective dosimetry. To understand the luminescence features of this crystalline media, a convenient thermoluminescence (TL) technique has been employed. Several well-defined theoretical models and methods were employed to calculate the kinetic parameters including the order of kinetics (b), activation energy (E) or trap depth, frequency factor (s) or escape probability and trap lifetime (τ), by analyzing the glow curves of the irradiated samples. The analysed trapping parameters indicate that the Toyota (E = 0.75–1.31 eV, s = 3.0E+6 – 3.7E+9 (s−1), τ = 6.9E+5 – 1.3E+14 s) and Honda (E = 0.95–1.68 eV, s = 2.1E+10 – 4.1E+13 (s−1), τ = 2.2E+9 – 3.1E+20 s) windscreen offer promising features for conventional TL dosimetry applications, while the obtained longer lifetime (τ = 6.8E+10 – 8.6E+29 s) or higher activation energy (E = 1.23–2.15 eV) for Proton brand windscreen indicates better stability or slow fading of the material, thus suitable for retrospective TL dosimetry. In addition, by assessing the area of deconvoluted micro-Raman spectra of windshield glasses in high-frequency regions, it has been observed the phenomenon of dose-dependent structural alterations and internal annealing of defects. This pattern is also consistent with those cyclical pattern observed in the intensity ratio of defect and graphite modes in the studies of carbon-rich media. Such common phenomena indicate the possibility of using the Raman microspectroscopy as a probe of radiation damage in silica-based media.

ESS화재 위험반경 고려 실내 체육시설 설치 및 안전 정책 방향에 관한 연구

This study attempted to derive an empirical formula that can measure the distance of the carbon monoxide risk radius and oxygen risk radius to ensure safety in the event of a fire in the ESS device of public indoor sports facilities. The derived empirical formula must consider the flow of the air, and in the case of public indoor sports facilities, it presents the airflow speed of 1m/s. Accordingly, it was substituted to the empirical formula and the findings derived the conclusion with 2.92500562m of carbon monoxide risk radius and 0.589756321m of oxygen risk radius. It was verified that in the case air-conditioner · heater is used in the public indoor sports facilities, the carbon monoxide risk radius will expand by around 1m and the oxygen risk radius will expand by around 0.1~0.2m. Moreover, the state suggests ESS installation in public sports facilities, but it is difficult to find manuals or legislation about fire accidents that could occur from installing ESS. Therefore, it is necessary to devise means of revision and policies that consider the ESS facility installation environment.

Smart Fire Detector utilizing IoT-based Zigbee Sensor

<pre>There are several differences between the two types of alarm systems, conventional systems and addressable systems. It is important to carefully determine the introduction of a fire alarm system according to the installation environment. Talking about the main difference relates to how the connected device communicates with the main control panel by sending a signal. Cost is another factor that can be a determinant of your chosen fire alarm system. In this paper, we proposed smart addressable fire detection system. In the proposed system, <span>IoT</span> was used and the network was constructed using <span>ZigBee</span> module. In the configured network, it consists of a local server and a control server. The local server controls the addressing sensor and sends the information obtained from the sensor to the control server. The control server receives data transmitted from the local server and enables quick fire action. In the actual implementation, the local server used the Lycra controller and <span>ZigBee</span> module. In addition, the control server used the Raspberry Pi and <span>ZigBee</span> modules and connected to the Ethernet so that the administrator could monitor or control the local server.</pre>