• Proceedings of the KIEE Conference
• /
• 1998.11a
• /
• pp.239-241
• /
• 1998

The probabilistic production simulation of power system generally has been used to formulate a reasonable power production plan or generation planning. It integrates the convolution process of a generating unit's random outage(FOR) with equivalent load duration curve(ELDC), and provides the reliability indices of power system. This paper presents the reliability characteristics of power system reflected on demand side management and proposes the modified ELDC representation technique due to the high-efficient end-use diffusion among the customers. Load reductions are simulated from the multi-state deconvolution process with the saved capacity of end-use. Case study shows the computed reliability from the power system production simulation incorporated with DSM planning scheme.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.6
• /
• pp.890-898
• /
• 2022

Dispersion of suspended sediment, caused by coastal and marine development, is a key item in assessing marine environmental impact as it adversely affects marine life by increasing the level of turbidity and decreasing the amount of sunlight in seawater. However, its estimation has not been reliable because of the absence of a standard for the data measurement and divergent approaches to the impact assessment. In this study, we examined the estimation models from 58 Marine Environmental Impact Statements (MEISs, 2012-2014) to identify the gaps in the assessment and devise ways of improving the estimation. We developed four index items-grid system; unit load, particle size, and settling velocit-to evaluate their reliability in the estimation. The mean reliability score of each index was overall low-25 for grid system, 60 for unit load, 34 for particle size, and 17 for settling velocity. To ensure high reliability, it is important to develop a standard guideline that defines precise measurement of suspended sediment for unit load and settling velocity by particle size, followed by a grid system with compatible size for modelling. This can improve the estimation and thus underlie coherent impact assessment of suspended sediment dispersion on marine environment.

• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.2
• /
• pp.65-70
• /
• 2015

In this paper, we describe the world's first real-time ray-tracing chip architecture. Ray-tracing technology generates high-quality 3D graphics images better than current rasterization technology by providing four essential light effects: shadow, reflection, refraction and transmission. The real-time ray-tracing chip named RayChip includes a real-time ray-tracing graphics processing unit and an accelerating tree-building unit. An ARM Ltd. central processing unit (CPU) and other peripherals are also included to support all processes of 3D graphics applications. Using the accelerating tree-building unit named RayTree to minimize the CPU load, the chip uses a low-end CPU and decreases both silicon area and power consumption. The evaluation results with RayChip show appropriate performance to support real-time ray tracing in high-definition (HD) resolution, while the rendered images are scaled to full HD resolution. The chip also integrates the Linux operating system and the familiar OpenGL for Embedded Systems application programming interface for easy application development.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.5
• /
• pp.314-320
• /
• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the improved wall insulation. Hence, a multi~heat pump is required to cover heating and cooling simultaneously for each indoor unit. In this study, the operating characteristics and performance of a simultaneous heating and cooling heat pump in the cooling-main operating mode were investigated experimentally. The system adopted a variable speed compressor using R410A with four indoor units and one outdoor unit. In the cooling-main mode, the heating capacity decreased due to reduction of flow rate to the indoor unit under heating mode operation. The EEV opening was adjusted to increase flow rate to the indoor unit under heating mode operation. The total capacity and COP in the cooling-main mode increased by 20.5% and 29.2%, respectively, compared with those in the cooling-only mode.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.5
• /
• pp.52-58
• /
• 2012

Experimental study was performed to understand the real operation conditions of a showcase working usually in a convenient store and discount store. The purpose of this study was to show the possibility for practical use of cold-heat storage systems being operated for the showcase. To do that, evaporator and condenser temperatures were measured and the compressor electric power consumption were measured simultaneously. To use the ice storage system, the ice making process was typically operated during midnight being not needed the cooling of the showcase through the continuous running of the condenser unit. And then, the refrigerant was subcooled using the stored cold-heat after being discharged from the condenser during daytime. So, the cooling performance was increased with the sub-cooling of refrigerant during daytime,hence the actual running time of the compressor could be effectively decreased. Through the experiments, this study showed that the compressor electric power consumption during daytime could be transferred to nighttime for applying the refrigerant sub-cooling. So, for the convenient store, the maximum load transfer rates for each working cooler and showcase were estimated about 31.1% and 19.9% respectively. And for the discount store, the maximum load transfer rates for each refrigeration and freezing showcase were estimated about 34.1% and 49.0% respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.12
• /
• pp.136-144
• /
• 2021

The purpose of this study was to develop and verify a precision transmission error measurement system for a gear pair. The transmission error measurement system of the gear pair was developed as a measurement unit, signal processing unit, and signal analysis unit. The angular displacement for calculating the transmission error of the gear pair was measured using an encoder. The signal amplification, interpolation, and transmission error calculation of the measured angular displacement were conducted using a field-programmable gate array (FPGA) and a real-time processor. A high-pass filter (HPF) was applied to the calculated transmission error from the real-time processor. The transmission error measurement test was conducted using a gearbox, including the master gear pair. The same test was repeated three times in the clockwise and counterclockwise directions, respectively, according to the load conditions (0 - 200 N·m). The results of the gear transmission error tests showed similar tendencies, thereby confirming the stability of the system. The measured transmission error was verified by comparing it with the transmission error analyzed using commercial software. The verification showed a slight difference in the transmission error between the methods. In a future study, the measurement and analysis method of the developed precision transmission error measurement system in this study may possibly be used for gear design.

• Journal of Korean Port Research
• /
• v.14 no.2
• /
• pp.155-163
• /
• 2000

A discrete system has interpreted by using the network model, and PERT network is one of these methods. For the purpose of analysing the real system, it is necessary to measure the parameter of the real system. And system identification problem is to assume the parameter of a real system when we get to know the system model, the input data and output data. System identification method has been only developed to a system of which a structure has expressed a differential equation or a polynomial expression. But it has been scarcely developed yet in that case of network model. The aim of this paper is to examine a changes when new system is introduced to the present system. The changes are as follows : how the present system will be changed, when the changes will be happened. In this paper, genetic algorithm is used to assume the parameter.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 1999.10a
• /
• pp.101-108
• /
• 1999

A discrete system has interpreted by using the network model, and PERT network is one of these methods. For the purpose of analysing the real system. it is necessary to measure the parameter of the real system. And system identification problem is to assume the parameter of a real system when we get to know the system model, the input data and output data. System identification method has been only developed to a system of which a structure has expressed a differential equation or a polynomial expression. But it has been scarcely developed yet in that case of network model. The aim of this paper is to examine a changes when new system isn introduced to the present system, The changes are as follows: how the present system will be changed, when the changes will be happened. In this paper, genetic algorithm is used to assume the parameter.

• Journal of Korean Society on Water Environment
• /
• v.37 no.1
• /
• pp.32-46
• /
• 2021

South Korea has been divided into quantities and water quality, and due to a revision of the Government Organization law in June 2018, the controversial water management system was integrated into the Ministry of Environment. The total Maximum Daily Loads System has been called the flower of water quality control, and since 2004, all three major river systems which have been introduced into the Han River system, despite its various difficult environments, and subsequently leading to all of the four major rivers undergoing obligatory implementation since 2013. Currently, the target TMDL (Han River Phase 1 and Other Water Systems Phase 3) for the 2020 stage has been implemented. The domestic TMDL established a basic plan for calculating the load which complies with the unit watershed's target water quality, as well as an implementation plan for annual load management, both which have been institutionalized in order to evaluate load compliance on a repeated annual basis. Local governments ask external organizations to conduct investigations every year in order to assess the transition, which thereby requires tens of millions of won every year. Therefore, an assessment and management model that can be easily operated at the TMDL personnel level is required. In this study, when the Han river Water System TMDL was implemented in earnest, we confirmed the the water quality improvement effect when TMDL was introduced to major inflow tributaries (TancheonA, JungnangA, AnyangA) under the Seoul City's jurisdiction through the use of the total amount control unit basin evaluation technique. By presenting customized management measures, we propose the guidelines that are necessary for determining more effective water environmental policies.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.85-90
• /
• 2014

We realized a wireless multiple integrated laser engagement system composed of personal area network using Zigbee. The wireless laser detector had function of analog signal processor, decoder and wireless communication. However, it should consume low power and be small and light in order to be attached to a soldier's body. The decoder was realized in software to be small and light. We induced low power consumption as reducing the load of system using a narrow band optical filter. The fabricated wireless laser detector functioned well in optically noisy environment. Although the communication to the player unit through the wireless personal area network was dependent on the attachment place it was perfectly worked with transmission power of -40.2dBm or more.