• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.3
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• pp.267-276
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• 2000

A numerical study has been carried out to find out the optimal design condition of a solar absorption cooling system. The system was composed of solar collectors and an absorption chiller with LiBr/water The System performance with commercial single effect(SE) cycle and a new single effect/double lift(SE/DL) cycle utilizing low temperature hot water was calculated and compared. It was found that the required solar collector area grew exponentially as the overall heat loss coefficient of solar collectors increased. For instance, the required area for cooling capacity of 1 USRT was $17m^2$ if heat loss coefficient was 4 W/$m^2\;cdot\;K$. If heat loss coefficient was doubled($8\;W/m^2\;cdot\;$K), the required collector area was increased by 6 times($100m^2$) .It was also found that the SE-cycle as the heat loss coefficient of solar collectors increased. Generally, a SE/DL-cycle seems to be more advantageous than a SE-cycle if loss coefficient of solar collector is greater than 4 W/$m^2\;cdot\;K$.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.1
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• pp.61-72
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• 2023

The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.3
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• pp.265-273
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• 2000

Basic simulation program for Vuilleumier cycle heat pump was developed that can use precise VMHP design and analysis. VMHP system was divided 11 sections in simulation. Simulation was used adiabatic model analysis and that considered with heat transfer performance for heat exchanger, regenerator loss, conduction loss, shuttle loss, pumping loss and pressure loss by flow friction. Specially, friction loss of connection pipe between heat compression side and heat pump side, leakage of rod seal and piston seal was considered in the analysis.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.1
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• pp.86-97
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• 2005

Nowadays, Water Mist Fire Extinguishing System is increasingly used in maritime field for various application. The fire extinguishing capability of the system should be verified by hydraulic calculation in the same manner as the conventional water based fire extinguishing system such as sprinkler system. water spray system and etc. Additionally, the review of effectiveness of friction loss calculation method used for hydraulic calculation is needed because the pipe flow characteristic of its piping system has higher Reynolds number than that of the conventional system. In this paper the review work was carried out based on the NFPA Code 750.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.2
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• pp.37-42
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• 2008

Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).

• Journal of the Korean Institute of Navigation
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• v.23 no.1
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• pp.1-13
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• 1999

Ship system can be divided into four sub-systems: hull, propeller, main engine and operation system which severely affect the characteristics of a ship. In determining ship speed in waves, two factors are considered the involuntary speed loss due to added resistance caused by wind and waves, and the voluntary speed loss by command of operation system to prevent severe ship motions. In this paper, the main function of four sub-system is analyzed for input/output relations and propulsive coefficient and a useful method to predict involuntary speed loss of a ship is presented. Two calculated examples for a high speed container ship and a passenger ship with single screw and diesel engine are given.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.773-777
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• 2005

This article is about using information technology to apply with water loss inspection system in District Metering Area (DMA). Inspector can check Flow rate and Minimum Night Flow; NMF via Smart Phone or PDA include sending SMS Alert in case the Pressure, Flow rate and NMF is over the range of controlling. This will be used as equipment to implement water loss in international proactive and can keep on water loss reduction more efficiency. The system consists of Data Logger which collects data of Flow rate from DMA Master Meter. PC is Wap Server which dial via modem in order to get data through FTP Protocal that will convert text file to Microsoft Access Database. Wappage will use xhtml language to show database on Wapbrowser and can show the result on Smart Phone or PDA by graph and table for system analysis.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.231-234
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• 2002

This treatise composes 450 [W] small size PV systems as thing for output elevation of PV system, investigated kind of output loss parameter. And, referred clear day and cloudy day about loss among the much parameters. Also, examined about loss between storage battery from system output part. Experiment result, could know that loss between storage battery is big from output part, and could know that output by that get dirty of module surface is decreased.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.18-23
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• 2013

This paper presents a simple but valid loss calculation method of grid-connected photovoltaic system based on normalized yield model. The proposed method can be represented as a quantitative value for five losses and performance of grid-connected photovoltaic system with three years monitored data. These results will indicate that it is useful to investigate various loss factors causing the performance obstruction, enhance the lifetime yield for changing meteorological conditions, and determine the optimal design and performance improvement of grid-connected photovoltaic system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.551-559
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• 2008

Increase in power consumption can cause a serious stability problem of an electric power system without construction of new power plants or transmission lines. Also, it can generate large power loss of the system. In costly and environmentally effective manner to avoid constructing the new infrastructures such as power plants and transmission lines, etc, the distributed generation(DG) has paid great attentions so far as a solution for the above problem. Selection of optimal location and size of the DG is the necessary process to maintain the stability and reliability of existing system effectively. However, the systematic and cardinal rule for this issue is still open question. In this paper, the method to determine optimal location of the DG is proposed by considering power loss when the DG is connected to an electric power grid. Also, optimal size of not only the corresponding single DG but also the multi-DGs is determined with the proposed systematic approach. The IEEE benchmark 30-bus test system is analyzed to evaluate the feasibility and effectiveness of the proposed method.