Overflow Type Research Articles

Effect of Submergence Condition and Overtopping Depth on Gully Scour Dimensions: Observations from the 2011 Great East Japan Tsunami

When a tsunami reaches a shore, it propagates along river channels with tremendous energy and overtops river levees. It causes severe damage to the levee structures through scouring along levee slope. In the present study, gully scours created along the levee slopes of two rivers (Omotogawa and Sakarigawa Rivers) in Iwate Prefecture and three rivers (Nanakitagawa, New Kitakamigawa, and Abukumagawa Rivers) in Miyagi Prefecture were investigated after the 2011 Great East Japan tsunami. The energy head during levee overtopping for each location was calculated from post-tsunami surveys. The relationship between the energy head and gully scour dimensions (length, width, and depth) was analyzed. The analyses clarified that gully scour dimensions were greatly dominated by two important phenomena: (i) overflow type (free overflow or submerged overflow), and (ii) soil texture at the scoured region. The present study results can be utilized to obtain the overtopping flow height for post-tsunami analysis.

Produktivitas Tiga Genotipe Kedelai dengan Air Berbeda dan Kedalaman Muka Air pada Berbagai Kondisi Tanah di Pasang Surut

<em>ABSTRACT<br /><br />Soybean extensification on mineral and peaty mineral soils of tidal land are limited by Al and Fe toxicity. Modification of growing environment and the use of tolerant variety are the possible alternatives to overcome the limitation. The research was aimed to study soybean productivity in various soil types with different depth of water level and different water compositions. The experiment was held under mineral, peaty mineral soils with interaction types B and C of tidal swamp in Banyuasin, South Sumatera from May to August 2014. At each location, there was a three factor experiment was arranged in a split-split plot design. The first factor was two water depth (10 and 20 cm), the second factor was three varieties (Tanggamus, Cikuray, Ceneng) and third factor was three different water compositions (river water, peat water, high-tide water). The results showed productivity on mineral soil types C, peaty mineral soil types B, and mineral soil types B were 4:50, 3.65, 0:32 ton ha-1 respectively. In peaty mineral soil types B, Ceneng with a depth of 20 cm water level resulted in highest productivity. In the mineral soil overflow type B, Cikuray with peat water composition had highest productivity.<br /><br />Keywords: mineral, peaty mineral, sensitive, tolerant<br /><br /></em>

Morfofisiologi Ratun Padi Sistem Tanam Benih Langsung di Lahan Pasang Surut

<p>ABSTRACT<br /><br />The morphophysiology of ratoon is different from the main plant of rice and was influenced by location and cultivation.This research was intended to evaluate morphophysiology characters of rice ratoon planted by direct seeding system in tidal swamp at various stubble cutting height. The experiment was conducted in November 2013-April 2014 at tidal swamp overflow type B in Telang Sari Village, District of Tanjung Lago, Banyuasin, South Sumatra Province. The experiment used randomized block design with 5 replications. Treatment was stubble cutting height 10, 20, 30, 40 and 50 cm above the soil surface. Rice was planted at 4 m x 5 m plot, the distance between plot 1 m. Data were analyzed by test of variance and 5% HSD test. Morphophysiological characters of rice ratoon were influenced by stubble cutting height. Cutting height of 20-40 cm above soil surface increased the ratoon number of tillers per hill, leaf area per hill, dry weight per hill, percentage of empty grains per panicle, grain weight per hill and percentage ratoon/main crop production per hill. The higher stubble cutting, the lower the number of leaves per tiller, leaf area per tiller, carbohydrate content, and number of grains per panicle of ratoon, however it accelerated age of flowering and harvesting. <br /><br />Keywords: direct seeding system, ratoon system, rice growth and production, stubble cutting height<br /><br /></p>

An analysis on ion transport process in electrodialysis desalination

An analysis based on the Nernst–Planck equation has been carried out on the transport process of salt ions in the ion-exchange membrane electrodialysis technology. The individual transport equations for both diluate phase and concentrate phase are considered to investigate the conservation of mass and salt ions driven by convection, molecular diffusion and electrophoresis. For the first time, the ion transport flow across the membranes driven by the osmotic pressure has been accounted for the overflow type of electrodialysis with the concentrate compartments sealed at the bottom end. The equations are integrated across the desalination channel and the concentrate reservoir to form one dimensional set of the transport equations with respect to the bulk velocities and concentrations of the diluate and concentrate phases. Subsequently, the equations are solved by the Runge–Kutta–Gill method, and the results are found to agree well with available experimental data. An analytic expression has been obtained for estimating a limiting current density.

Scoured depth and length of pools and ditches generated by overtopping flow from embankments during the 2011 Great East Japan Tsunami

The characteristics of scoured regions behind embankments generated by the 2011 Great East Japan tsunami were investigated along the Abukumagawa River, where severe erosion by overtopping of river embankments had occurred, and four other locations. To quantitatively estimate the relationship between the damage and hydraulic parameters, the tsunami was simulated by non-linear long wave equations and a fault motion model. The maximum energy head and momentum express the maximum scoured depth and length, but the overflow type, free or submerged, also greatly affects the scour characteristics. Even on the far side of the river mouth, the scoured depth and length were large because propagation of the tsunami in the river was faster and overflow occurred as a free type affected by the local conditions of the river, i.e., a meandering course and damming by the bridge girder. The relationship obtained by this real-scale study can be utilized to estimate the maximum scour depth and length behind the embankment, to design footings for embankments, and to estimate the extent of the tsunami in post-tsunami surveys.

Optimization of coagulation–flocculation process for combined sewer overflow wastewater treatment using response surface methodology

A different type of combined sewer overflow (CSO) problem in dry weather, with characteristic of high organic pollutant loads and wide variations, has been becoming one of the most serious urban river pollution problems in China. The performance of coagulation–flocculation process in this type of CSO wastewater treatment was investigated in this study, using polyaluminum ferric chloride sulfate (PAFCS) as coagulant. A 23 full-factorial central composite design and response surface methodology were applied to evaluate the effects and interactions for the chemical oxygen demand (COD) removal efficiency by three factors including initial COD concentration, initial suspended solid concentration, and coagulant dosage. A quadratic model was obtained and the analysis of variance results indicated clearly that experimental data could fit the equation well with a R2 of 95.15%. There is a significant interaction between the initial COD concentration and coagulant dosage for COD removal efficiency. The experimental data and model predictions agreed well. The quadratic model was demonstrated to be an appropriate approach in prediction of the coagulant dosage or COD removal efficiency in this type CSO wastewater treatment using coagulation–flocculation process.

Numerical Modeling of Hydraulic Performance of Piano Keys Overflows with Different Geometry

Abstract. In this study, the properties of hydraulic flow were done on the piano keys overflow in the various geometric models by three-dimensional mathematical model of 3D Flow. The Hydraulic properties regarded in this study are the flow rate flood coefficient . In this study, the flow was considered kind of permanent, perturbation flow and incompressible fluid. The perturbation model used in this study is . Determination of free level profile was done by the use of VOF. The boundary model conditions include input level, output level, wall and free surface flow. The results show that the mathematical model accurately is capable of modeling this type of overflow. The results also show that the the piano keys overflow has higher discharge flood coefficient in compare to corresponding staggered overflow. Investigating the ratio of input key width to the output key width show that the range of 1.25 to 1.5 has the highest rate flood coefficient. The rate of flood coefficient in overflow of piano keys is more than the overflow of rectangle staged overflow with slope cycle. Also, overally the rate of flood coefficient in the model with the only outlet slope is more than the model with inlet slope and a model combined with outlet and inlet slope. Among the various models, the rectangle staged overflow with inlet slope keys has little engative effect on the rate of flood coefficient. The results of the study indicate that using the basis makes the rate of flood coefficient increased. Using a shield wall makes the rate of flood coefficient increased. The comparison of the findings showed that the rates of flood coefficient in PKRFH model was firstly more than the rates of flood coefficient in PKRFF (crests) but by increasing Ht/p the rates of flood coefficient gets gradually closer in the two models.

Modal Analysis of Oversize Ball Mill Tube Based on ANSYS

The ball mill is one kind of breaking plants which used widely in building materials, metallurgy, mineral processing and so on. The finite element method is used to build the model of the 7.32× 11.28 overflow type ball mill. And then modal analysis of oversize ball mill tube is carried out by ANSYS workbench, which leads to the intrinsic frequency and model of vibration of tube. The analysis result can be reference for the design of ball mill.

Dynamics of Turbid Plumes Generated by Marine Aggregate Dredging: An Example of a Macrotidal Environment (the Bay of Seine, France)

Duclos, P.-A.; Lafite, R.; Le Bot, S.; Rivoalen, E., and Cuvilliez, A., 2013. Dynamics of turbid plumes generated by marine aggregate dredging: an example of a macrotidal environment (the Bay of Seine, France).On the French marine shelf, marine aggregates are currently dredged by trailing suction hopper dredgers (TSHD), without screening, with an overflow process, with or against currents. In the framework of the Groupement d'Interét Scientifique (GIS) Suivi des Impacts de l'Extraction de Granulats Marins (SIEGMA), the dynamics of the turbid plume formed by the overflow was studied at an experimental dredging site (0.6 km2), located in the Bay of Seine (eastern English Channel), a macrotidal environment where the seabed is composed of sandy gravel. An original field strategy based on Lagrangian monitoring, using the back-scattered signal of an Acoustic Doppler Current Profiler (ADCP), Laser In Situ Scattering and Transmissometry (LISST) measurements, water samples, and aerial photographs, has shown good results in describing suspended sediment concentration (SSC) dynamics from a turbid plume. The behaviour of suspended sediment has been studied, for the first time, to our knowledge, from their release at the dredger overflow to their deposition on the seabed. A fluid mixture, overflowed from the TSHD, with a mean concentration of 6 g L−1 of mineral and organic silty sands, induces the formation of a turbid plume at the rear of the TSHD, with an immediate dilution effect about 10–100 on SSC. Then, the SSC decreases through the process of lateral dispersion and sedimentation until the plume disappear in 2 hours. Evolution of the plume characteristics (SSC, particle size and nature, geometry) makes it possible to quantify the processes involved: dilution, advection, dispersion, and settling. The passive and dynamic behaviours of the plume are analysed. Extensions of deposits are calculated for spring tide conditions: 800 m for sand and 6.5 km for silt. This study has been conducted in macrotidal and specific dredging conditions (orientation of the dredging tracks against currents, dredger speed, loading capacity, overflow type), whose effects on plume dispersion have been quantified. Indicators relative to the effect of the plume on the water column (I/R) and to the plume duration (T1.25SSC) are proposed.

Experimental Study on Optimization of Wet Desulfurization of Wet Ball Mill System

In this paper, the output can not meet the operating requirements problems of power plant desulfurization device wet mill system operation, site of the optimization test of wet mill system, optimization and adjustment, wet mill output and fineness of limestone reached or better than the design value, the operation time was shortened, and achieved good economic and social benefits. With reference to the same type of wet overflow type ball mill.

보 유출형태에 따른 하류부 도수 및 비에너지 손실에 관한 비교 연구

기존까지 건설된 보는 대부분 보의 상단으로 월류하는 월류형 보가 주종을 이루고 있다. 월류형 보의 경우 수자원의 관리의 효과와 지금까지의 많은 연구로 인한 설계, 시공 및 유지관리 방법 등이 용이 하다는 장점이 있다. 하지만 월류형 보의 특성상 보 상단부를 통해 물이 월류되는 방식이기 때문에 상류부로부터 유입된 유사가 보 하류로 배출되지 못하고, 하상이 높아지면서 저수용량이 감소되어 점차 보의 기능을 상실하게 된다. 이와 같은 토사 퇴적 및 보의 유지관리 문제를 해결하기 위해 수문을 가진 하단방류형 보가 건설되기 시작하였다. 하지만 최근 건설된 하단방류형 보의 설계상의 문제점으로 인하여 보 하류부의 하상이 세굴되고, 세굴된 하상 때문에 구조적인 문제점이 발생되고 있다. 본 연구에서는 보의 효과적인 설계 및 운영방법을 위해 월류형 보와 하단방류형 보의 흐름의 특성, 하류부 수위 변화에 따른 도수길이분석, 보 형태에 따라 단위거리당 발생되는 비에너지 손실량을 비교 및 분석하였다. 실험분석 결과 하단방류형 보와 월류형보의 상류 조건을 동일하게 유지 시 하단방류형 보에서 도수의 길이가 Fr 값(Froude number) 3.5에서 최대 2배 길게 나타났으며, 하류 수위가 증가 할수록 도수의 길이는 점차 감소하게 되었다. 단위 거리당 발생되는 비에너지 손실량 비교 분석 결과 단위 거리당 에너지 손실량이 하단방류형 보에 비해 월류형 보가 약 2배 높게 나타나는 것으로 판단되었다. 따라서 하단방류형 시설의 경우 수공 구조물의 안전을 위해 별도의 에너지 감세시설을 별도로 검토하는 것이 바람직한 것으로 판단된다. The weirs built so far are mainly overflow type weirs overflowing to the upstream. Main advantages of overflow type weirs are, effective water resources management and easy design, construction and maintenance due to many accumulated studies. However, due to the special feature of the overflow type weir where water overflows through the upstream of the weir, the silt coming from the upstream is not discharged to the downstream of the weir. This increases the river bed and reduces the reservoir capacity, and as a result, the weir loses its function. A underflow type weir with a water gate has been implemented in order to solve such sediment deposit and weir maintenance problems. However due to the design problem of recently constructed underflow type weirs, the river bed of the downstream of a weir has been scoured. And this leds to a structural problem. In this study, the flow characteristics of overflow type weirs and underflow type weir, hydraulic jump length analysis depending on change of water depth and the amount of specific energy loss generated per unit length depending on a weir type have been compared and analyzed, for the effective design and management of the weirs. The experiment results show that, when identical upstream conditions of underflow type weir and an overflow type weir were maintained, the hydraulic jump length was up to twice longer with Fr(Froude number) 3.5 of the hydraulic jump length at the underflow type weir, and the hydraulic jump length gradually decreased as the downstream water depth increased. The comparative analysis result of the amount of specific energy loss generated per unit length showed that the amount of energy loss per unit length was twice higher for an overlfow type weir than a underflow type weir. Therefore, in case of a underflow type facility, an additional energy reduction facility is determined to be necessary for safety of water construction structures.

Automated Malware Detection Based on Novel Network Behavioral Signatures

In this paper we introduce the second generation of the experimental detection framework of AIPS system which is used for experimentation with detection models and with their combinations. Our research aims mainly on detection of attacks that abuse vulnerabilities of buffer overflow type, but the final goal is to extend detection techniques to cover various types of vulnerabilities. This article describes the concept of detection framework, updated set of network metrics, provides a design of model architecture and shows an experimental results with draft of framework on the set of laboratory simulated attacks. Index Terms—Artificial intelligence, behavioral signatures, metrics, network security, security, security design. 112 metrics divided into five categories according to their nature. These metrics are used to describe properties of detected attack not upon the fingerprint of common signature, but based on its behavior. During the experiments we found several limitations of the original idea and some parts of the architecture were changed. We extended the metric dataset to 169 metrics containing approximately 4000 parameters and changed the categories to reflect the nature of the new dataset. The main goals of this research is (a) to design the architecture of detection framework that will enhance the overall network security level with the ability to learn new behaviors of attacks without intervention of human by using the expert knowledge from Honeypot (or similar) systems; (b) to find the most suitable set of metrics that will successfully describe the behavior of attacks in the network traffic and will significantly higher the detection rate and lower the false positive rate. In this article we introduce the second generation of the experimental detection framework of AIPS system which is used for experimentation with detection models and with their combinations. The fundamental principle of the detection is based on evaluation of metrics set, which describes the behavior of attack. These metrics are formally specified and extraction of them can be generally realized for each data flow. We could interpret the specification of metrics set as formally extended protocol NetFlow (9), which describes more than statistical properties of network

OPTIMASI POLA TANAM DAN ALOKASI INPUT UNTUK PENINGKATAN KETAHANAN PANGAN RUMAH TANGGA DI LAHAN PASANG SURUT KABUPATEN KUBU RAYA KALIMANTAN BARAT

The research was conducted in the district of Kubu Raya which is focused on swamp land. The purpose of this study are (a) optimizing the allocation of cropping pattern and input to achieve household food security and income maximum, (b) to simulate changes in input prices and output and its impact on cropping patterns, household income, and allocation of inputs. Location selected by purposive sampling technique taking into account the typology of land and type of overflow, whereas the primary data collected from farm households by simple random sampling technique. Data were analyzed with linear programming and sensitivity analysis. An important result of this study are as follows: (1) Optimal cropping patterns in swamp lands are as follows: (a) the type of SMA / A, paddy field: rice - rice, (b) the type of SMP / A, paddy field: rice - rice, and dry land: coconut, (c) type SMP / B, paddy fields: corn-corn, and dry land: fruit, (d) the type of SMP / C, paddy field: rice-paddy and dry land: coconut, (e) type bergambut / B, wetland : paddy-rice, and dry Ahan: coconut, (f) type bergambut / C, paddy field: rice-paddy and dry land: coconut, (g) the type of peat is / B, the paddy field: rice-paddy, (h ) the type of shallow peat / D, wet land: paddy-rice, and dry land: rubber; (2) the optimal allocation of inputs consisting of family labor 166.74 day of man work/year, rent labor 132.74 day of man work/year, seed of paddy 70.54 kg/year, Urea 189.28 kg/year, SP36 94.34 kg/year, KCl 56.35 kg/year, NPK 75.66 kg/year, organic fertilizer 65.99 kg/year, herbicide 8.62 lt/year, dan pesticida 2.29 lt/year; (3) the actual household income of Rp 2,200,000.00 / household / year, if carried out optimization of unconditional “food patterns of national expectations/FPNE” increased to Rp 3,883,234.87 / household / year and if there is a requirement of the FPNE decreased to Rp 1,285,839.37 / household / year. (4) the price of rice and corn prices are most sensitive to fluctuations. If the price of rice rose more than 5% or the price of corn rose more than 50% (cateris paribus) the optimal solution will change. Likewise, if the price of rice fell by more than 34% or corn prices fell more than 9% (cateris paribus) the optimal solution will change. (5) The simulation results show that the rise in input prices and output prices 10% did not alter the optimal solution. But the impact on household income increased by 37.87% (unconditional FPNE), and 114.37% (provided FPNE). Simulated 10% decrease in output price and input prices fixed, it does not alter the optimal solution, but the impact on the decline in household income by 152.15% (unconditional FPNE) and 459.49% (provided FPNE). Keywords: optimize, farm household, swamp area, food security,

Fixed Point Data Type Modeling for High Level Synthesis

A methodology to automatically convert fixed point data type representations into integer data types for high level synthesis is presented in this work. Our method converts all major C operations using fixed point data types into integer data types, models quantization and overflow modes, type conversion and casting. The conversion rule for each operation is described in detail as well as a regression test environment with 600 test cases to validate the method and to verify the correctness of each conversion compared to the same cases written in SystemC. The test environment converts each test case with fixed point data types into integer data types and synthesizes them with a high level synthesis tool to generate RTL. An RTL simulation is ran and the results in turn compared to the SystemC's OSCI simulation. For all of the 600 test cases the RTL simulation results matched the SystemC results proving that each conversion is accurately modeled. A larger real test case is also presented to validate the conversion method in a complex case.

도시하천의 교각 및 횡단 월류형 구조물에 의한 수리영향 분석

도시하천의 교각 및 횡단 월류형 구조물에 의한 수리영향 분석

Tandem queue with server slow-down

We study how rare events happen in the standard two-node tandem Jackson queue and in a generalization, the socalled slow-down network, see [2]. In the latter model the service rate of the first server depends on the number of jobs in the second queue: the first server slows down if the amount of jobs in the second queue is above some threshold and returns to its normal speed when the number of jobs in the second queue is below the threshold. This property protects the second queue, which has a finite capacity B , from overflow. In fact this type of overflow is precisely the rare event we are interested in. More precisely, consider the probability of overflow in the second queue before the entire system becomes empty. The starting position of the two queues may be any state in which at least one job is present.

Hydrogeomorphic types of glacially created kettle holes in North-East Germany

Kettle holes are glacially created, small, shallow, depressional wetlands collecting their water from internal or closed catchments in young moraine landscapes. Their water body is defined by having a maximum of 1 ha in extent. Mostly they undergo a wet-dry circle. In North-East Germany, kettle holes are widely spread, mostly on arable land. They are characterised by large differences in hydroperiod (HP), size, shape and edge steepness. They also have a high potential for both, geomorphic structural diversity and biological species diversity. However, kettle holes are subject to pollution, drainage and structural reduction that result from intensive land use practices. Although kettle holes in Germany are protected by law, protection strategies are not specific enough with respect to the variability of kettle holes, especially of HP. Therefore, the study objective was to characterise hydrogeomorphic (HGM) kettle hole types to create a basis for a decision support system with regard to the selection of the type dependent conservation and management measures. In three agricultural landscapes in North-East Germany, geomorphological and hydrological variables of 268 kettle holes (HP, shore overflow tendency, depth, area, form, shore width and slope) as well as those of their catchments (area, wetland to catchment area ratio, relief) were investigated from 1993 to 2003. By statistical analysis of datasets of 144 kettle holes, 10 HGM kettle hole types were defined. The basic types are “silted fen type” and “open-water type”. Basic subtypes of the latter type are “storage type”, “shore overflow type” and “puddle type”. Differences in spreading of kettle hole types in dependency on landscape relief were found.

Modulation of spontaneous and stimulation-evoked transmitter release from rat sympathetic neurons by the cognition enhancer linopirdine: insights into its mechanisms of action.

The mechanisms by which the cognition enhancer linopirdine may affect transmitter release were investigated in cultures of rat superior cervical ganglion neurons. Overflow of previously incorporated [3H]noradrenaline evoked by 10 microM UTP or 0.1 microM bradykinin was enhanced by linopirdine at > or =3 microM, overflow evoked by 25 mM K(-), 100 microM nicotine, or 300 microM ATP was enhanced by linopirdine at > or =10 microM, and overflow due to 40 mM K+ or electrical field stimulation was not altered by linopirdine. Ba2+ (0.3 mM) augmented the same types of stimulation-evoked overflow to a similar extent as linopirdine. K+ (25 mM), nicotine (100 microM), and ATP (300 microM) triggered transmitter release in a partially tetrodotoxin-resistant manner, and the release-enhancing action of linopirdine was lost in the presence of tetrodotoxin (1 microM). Linopirdine (10 microM) raised spontaneous tritium outflow and reduced currents through muscarinic K+ (K(M)) channels with a similar time course. The secretagogue action of linopirdine was concentration- and Ca2(+)-dependent and abolished by tetrodotoxin (1 microM) or Cd2+ (100 microM). Linopirdine (10 microM) added to the partial inhibition of K(M) channels by 1 or 3 mM Ba2(+) but not to the complete inhibition by 10 mM Ba2(+). Likewise, the secretagogue action of 1 and 3 mM, but not that of 10 mM, Ba2+ was enhanced by linopirdine. These results indicate that linopirdine facilitates and triggers transmitter release via blockade of K(M) channels and suggest that these K+ channels are located at neuronal somata rather than at presynaptic sites.

Trial manufacture of eccentric roller type total artificial heart.

Working toward a completely implantable total artificial heart, we have designed an eccentric roller type total artificial heart. The actuator of this artificial heart is a drum type eccentric roller that squeezes the blood chambers. The blood chambers are made of silicone rubber and are torus in shape. The shape of the artificial heart is an almost circular cylinder, and its length and diameter are 10 cm and 8 cm, respectively. The 2 main characteristics of this artificial heart are that it discharges blood in a pulsatile mode and that it requires no reversing of the motor. Because we have not completed the artificial heart yet, we have tested the eccentric roller mechanism on the prototype with an overflow type mock circulation with a 100 mm Hg afterload. The prototype worked at the roller speeds of 50, 100, and 150 rpm with flow rates of 1.7, 3.7, and 5.4 L/min, respectively. Next the prototype was connected to a Donovan type mock circulatory system and worked at roller speeds of 88-214 rpm with flow rates of 3.0-8.4 L/min against mean afterloads of 82-120 mm Hg.

A flow‐executing scheme for DOACROSS loops on dynamic dataflow machines

AbstractThis paper modifies a flow‐executing scheme of the color‐reuse type, using multiple initial loop control packets, and then proves that the flow‐executing scheme is best suited for executing DOACROSS loops on dynamic dataflow machines. Flow‐executing schemes can be divided into four categories: (1) those using a single initial loop control packet; (2) those using multiple initial loop packets; (a) the color overflow type; and (b) the color reuse type. Then the flow‐executing scheme can be classified into Classes (1‐a), (1b), (2‐a), and (2‐b) through the combination of Categories (1), (2), (a), and (b). This paper suggests that Class (2‐b) is best suited for executing DOACROSS loops, as it extracts full parallelism from DOACROSS loops, no sychronization overhead exists, and no memory access overhead exists after the synchronization.