• Korean Journal of Organic Agriculture
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• v.2 no.1
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• pp.2-15
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• 1993

Major vegetables and fruits in Korea are grouped in 3 Categories according to the Concentration of NO3- content in edible parts of the plant. NO3- content are high in order fruit

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.53-56
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• 1996

The conventional inventory models are concerned with the items of which utilities and amount of numbers are constant over time. But in practice the items in inventory systems are increasing or decreasing. This study is concerned with the development of ameliorating inventory models. The ameliorating inventory is the inventory of goods whose utility increases over the time by ameliorating activation. The term ameliorating inventory is used in this paper at least, since the terminology is not standard well known. This study is performed according to areas; one is an economic order quantity(EOQ) model for the items whose utility is ameliorating in accordance with Weibull distribution, and the other is a partial selling quantity(PSQ) model developed for selling surplus inventory accumulated by ameliorating activation. Computer programs are developed to obtain the optimal ordering and selling quantity. Numerical examples to illustrate the effect of ameliorating rate on inventory polices are shown at the end of this paper.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.117-120
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• 2006

In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE(Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detaiil. The main concept of PV-AF system starts from the 'harmonics'. In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately However, in this paper, characteristics and advantages of combined system are discussed in detail.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.119-130
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• 2018

The VE/LCC study on the existing multi-utility tunnel examined the economical feasibility of the collective area through the cost-benefit analysis of the ten major routes of Seoul for the benefit (7 items) and the cost (5 items) through quantitative methods. In this paper, we analyzed the economic efficiency of 61 sectors by adding 3 items (reduced traffic accident, reduced vehicle noise, social-economic loss). The reduced traffic accident item is an improvement of the traffic accident cost that can be saved by the implementation of the project, and the reduced vehicle noise item is an indicator of the amount of noise change caused by the implement of the business. Finally, the social-economic loss items represent the impact on the local economy due to the construction of the multi-utility tunnel. The amounts of the additional items were compared and items added in the open type and tunnel type multi-utility tunnel were analyzed for each analysis. Result on the analysis, it analyzed the items applied to the basic and detail models in the economic evaluation of the multi-utility tunnel design, and makes it possible to evaluate the economic efficiency more efficiently. The economic evaluation of the basic and detailed models including the items presented in this study will be often used in the design of the multi-utility tunnel design.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.106-115
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• 2007

The size and length of road tunnels have been gradually expanded as industry developed. Consequently, the risk has been increased. The decision making process for ventilation system for road tunnels involves a large amount of information on economic feasibility, construction methods, and safety etc. In situation where systematically structured decision making process is unavailable, almost decisions about ventilation systems are made based on engineers' private knowledge and experiences. Procedure and criteria to choose the best optimized ventilation system among many alternatives are proposed, breaking away from the economic dependency-oriented decision making. This paper presents a Multi-Attribute Utility Theory and AHP based function with which planners can calculate overall utility of each alternative. It is anticipated that the effective use of the proposed methodology for decision making on ventilation systems ould be able to reduce the likelihood of the occurrence of potential safety risks as well as increase the overall ventilation performance.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.159-179
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• 2022

Often a network becomes complex, and multiple entities would get in charge of managing part of the whole network. An example is a utility grid. While the entire grid would go under a single utility company's responsibility, the network is often split into multiple subsections. Subsequently, each subsection would be given as the responsibility area to the corresponding sub-organization in the utility company. The issue of how to make subsystems of adequate size and minimum number of interconnections between subsystems becomes more critical, especially in real-time simulations. Because the computation capability limit of a single computation unit, regardless of whether it is a high-speed conventional CPU core or an FPGA computational engine, it comes with a maximum limit that can be completed within a given amount of execution time. The issue becomes worsened in real time simulation, in which the computation needs to be in precise synchronization with the real-world clock. When the subject of the computation allows for a longer execution time, i.e., a larger time step size, a larger portion of the network can be put on a computation unit. This translates into a larger margin of the difference between the worst and the best. In other words, even though the worst (or the largest) computational burden is orders of magnitude larger than the best (or the smallest) computational burden, all the necessary computation can still be completed within the given amount of time. However, the requirement of real-time makes the margin much smaller. In other words, the difference between the worst and the best should be as small as possible in order to ensure the even distribution of the computational load. Besides, data exchange/communication is essential in parallel computation, affecting the overall performance. However, the exchange of data takes time. Therefore, the corresponding consideration needs to be with the computational load distribution among multiple calculation units. If it turns out in a satisfactory way, such distribution will raise the possibility of completing the necessary computation in a given amount of time, which might come down in the level of microsecond order. This paper presents an effective way to split a given electrical network, according to multiple criteria, for the purpose of distributing the entire computational load into a set of even (or close to even) sized computational loads. Based on the proposed system splitting method, heavy computation burdens of large-scale electrical networks can be distributed to multiple calculation units, such as an RTDS real time simulator, achieving either more efficient usage of the calculation units, a reduction of the necessary size of the simulation time step, or both.

• 전기의세계
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• v.24 no.6
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• pp.97-101
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• 1975

The electrical neuronal model described in this paper simulates the most important functional properties of nerve cells. An model circuit incorporating many of the digital and analog properties of neurons is described. Having such properties as variable threshold level, action potential, summation, all-or-none output, absolute and relative refract oriness, and ingibition, it exhibits a considerable amount of functional equivalence to biological structures. This electrical neuronal model has utility not only for studying single unit properties but also for investigating group interactions. Such studies may be relevent to elucidation of neuronal network behavior.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.21-22
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• 2022

High fluidity concrete has excellent workability, and if the cross-section of the building is complicated, it is possible to place good quality concrete and increase the construction speed, so its utility value is very high. However, it is premised on the accuracy of concrete formwork assembly. Concrete leakage through formwork gaps is an important consideration when applying high flow concrete. In order to quickly solve the leak of high fluidity concrete caused by formwork gap occurring at the site by accelerator injection, we proceeded with research to confirm the possibility of reducing the amount of formwork leakage of high fluidity mortar. It was confirmed that the injection of the accelerator could reduce the amount of mortar leakage.

• Asian-Australasian Journal of Animal Sciences
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• v.1 no.2
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• pp.99-106
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• 1988

A high performance liquid chromatographic procedure is described for the direct determination of the picomole amount of palmitoyl-Coenzyme A and stearoyl-Coenzyme A, using a stainless steel column packed with C-18 derivatized porous silica ($5{\mu}m$), an isocratic elution with a mixture of 33 mM $KH_2PO_4$/acetonitrile as a mobile phase and a UV detector. The long-chain acyl-Coenzyme A esters were determined in incubated microsomal fractions of a bovine liver to demonstrate the utility of this method for monitoring acyl-CoA synthesis in biological samples. The reaction rate of palmitate was higher than that of stearate. After a 60 minute incubation period, the generated amount of palmitoyl-Coenzyme A and stearoyl-Coenzyme A were approximately 70 and 20 n mol/mg micresomal protein, respectively. The advantage of this method are in that no decomposition of the CoA esters is involved, while the constituent molecular species is detected.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.119.2-119
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• 2001

The inspection of a meter is an action that measures the amount of electricity, water and gas used to impose user on a charge. In past days, a meter who visit consumer to look over meter and write data to the ledger and then go back his office to calculates the inspection of a meter. On the other hand, the AMR(Automatic Meter Reading) is remote control system to measure the amount of utility used and monitor a condition of the meter. A study about AMRS is started at 1960 all over the world and a successful application example is presented continuously in American, Europe and Japan etc. In this paper we use a check meter that is used in past days and we add an AMR to it. AMR receives data that is the amounts of electricity from the check meter and stores those ...