• Proceedings of the Safety Management and Science Conference
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• 2008.04a
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• pp.135-147
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• 2008

The package loading process of the lumbering industry is an operation that after a pair of workers bind three or six lumbers into one unit and cut both ends of the lumbers, transports the weight cargo of 30-50kg by one meter, pack and load at a height of 1.2 meters. This package loading process causes lots of noise and wood dust when workers carry out the heavy work as the above. Therefore we developed the monolithic both ends cutting package loading equipment in order to prevent from getting musculoskeletal disease. An loading bar working system of this equipment is improved from pneumatic pressure system to oil pressure system, furnished the newly designed flow dividers, and developed the new system that a both end array is loaded identically. Also we developed the safety equipment of loading bar in order to prevent workers mistake and overload from malfunction during the package loading process. The main cause of job evasion on working place could be solved by preventing the musculoskeletal disease and improving the working environments.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.1
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• pp.18-22
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• 2015

When using a secondary battery in energy storage units, if the grid is in light duty the active power is stored so it can be used when the grid is in heavy duty. This makes possible for the load equalize and make the grid optimized. Recently the government is trying to propagate this technology. Depending on its capacity this kind of electric energy storage unit is used in adjusting the frequency, break up the energy peak in summer and winter, stabilize the energy output of renewable energy which can change unstably because of the environment. Which makes it possible to stabilize the grid. It is anticipated that market of 120 trillion won will be developed worldwide in 2030. Currently in Korea a steady supply is in progress. However because of stray electromagnetic waves some other electronics are malfunctioning. This paper covers the research in the method to detect the emission noise in small electric energy storage units using lithium secondary batteries and battery management system, Power conditioning systems with CIPSR standards. And the research of a more efficient method to measure such stray electromagnetic waves.

• Solar Energy
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• v.2 no.1
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• pp.49-58
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• 1982

Aim of this study was to obtain the heating performance and the economic evaluation on solar heating system for greenhouse which area of floor was $90m^2$. For heating performance effective solar energy for the greenhouse was compared with overall heating loads including coefficient of heat transfer and conduction. And the economic evaluation solar heating system was evaluated by comparison its initial investiment costing with oil saving cost. Initial investiment costing included collector cost, storage cost, piping cost, control system cost and miscellaneous costs which included pumps, motors etc. The contents of this study included the survey of climate conditions for solar heating, long-term collector performance and optimum collector area of solar heating system in existing greenhouse. The results are follows: 1. Average horizontal radiation during winter was $2,434Kcal/m^2$ day which was the highest value in this country, so the climate conditions of Suwon was suitable for solar heating. 2. Resulting calculation of the optimum collector area was $30m^2$ and the solar energy accounted for 30% of the overall heating load. 3. The capacity of storage tank required 60 liter per unit area ($m^2$) of solar collector.

• Journal of the Korean Solar Energy Society
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• v.40 no.3
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• pp.1-20
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• 2020

In accordance with the Government's policy, renewable power generation is expanding very largely. This leads to increasing uncertainty in the power market and power system owing to the intermittent and fluctuating output characteristics of renewable power generators. Data on the acquisition of renewable power generators can be largely classified according to the operation of the power market and power system. Data on the settlement for the payment for the power amount are acquired in the power market, and real-time data for monitoring the status and output of the generators are acquired in the power system. However, renewable power generators operating in the power market have different acquisition cycles depending on the method of communication of the power meter. They acquire data only for settlement purposes and have no real-time data, which requires improvement. In this paper, the acquisition status is reviewed by classifying the data of renewable power generators into settlement and real-time data. In addition, measures and acquisition criteria for real-time data of renewable power generators for improving the acquisition method are proposed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.93-99
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• 2019

A cross drilling/milling Unit is an important mechanical part which is widely used in many kinds of machining tool, and various gear trains with good accuracy and reliability features are widely used in power transmission systems. A study on a novel power transmission optimization method for driving gear trains in cross drilling/milling units is presented in this paper. A commercial program for gear system simulation, Romax Designer, was used in this research to intuitively observe the gear meshing and the load distribution conditions on the gear teeth. We obtained the optimal modification value through comparing the results of repeated experiments. For validation, optimized gears were fabricated and then measured with a precision tester.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.597-600
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• 2006

인터넷 기술의 발전으로 우편물류시스템은 우편집중국을 중심의 허브-스포크 구조를 기반으로 자동화 우편소통 시설과 우편물류정보시스템 구축 등의 많은 변화와 발전을 해왔다. 현행 우편물류정보시스템은 바코드를 기반으로 정보의 교환 및 처리를 수행하며, 물류정보의 수집, 처리 및 활용에 있어서 실시간성과 동적인 운용 측면에서 진일보하기 위해서는 차세대 정보기술인 RFID를 지원하기 위한 연구가 필요하다. 따라서 이 논문에서는 우편물류의 운송용기를 중심으로 업무 및 시스템을 분석하며, 업무 효율성과 생산성 개선을 위해 RFID 기술을 적용하기 위한 정보처리시스템 모형을 설명한다.

• Journal of Power Electronics
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• v.9 no.6
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• pp.919-928
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• 2009

Microgrids (MGs) are typically comprised of distributed generators (DGs) including renewable energy sources (RESs), storage devices and controllable loads, which can operate in either interconnected or isolated mode from the main distribution grid. This paper introduces a novel dynamic programming (DP) approach to MG optimization which takes into consideration the coordination of energy supply in terms of heat and electricity. The DP method has been applied successfully to several cases in power system operations. In this paper, a special emphasis is placed on the uncontrollability of RESs, the constraints of DGs, and the application of demand response (DR) programs such as directed load control (DLC), interruptible/curtaillable (I/C) service, and/or demand-side bidding (DSB) in the deregulated market. Finally, in order to illustrate the optimization results, this approach is applied to a couple of examples of MGs in a certain configuration. The results also show the maximum profit that can be achieved.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.942-945
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• 2001

This paper presents parallel operation of ZVT(Zero Voltage Transition) Full Bridge Converter with Dynamic Current Shared Inductor. In the conventional method, CT(Current Transformer) have been used to share the load current equally with converters. In this system, at parallel operation of ZVT Full Bridge Converter, dynamic current shared inductor divides the same current of unit converter and ZVT circuit aids to high efficiency. This method which is proposed to compare in the conventional method will do simple control circuit. To show the superiority of this converter is verified through the experiment with a 2kW, 50kHz prototype converter.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.175-182
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• 2009

Needs on ensuring compatibility and conformity of equipments that are used in logistics functions - such as packaging, transporting, loading/unloading and storing - are raised. This article presents a classification scheme for analyzing the interfacing characteristics of logistics equipments focusing on standardized pallets of unit load system. International and domestic classification systems are reviewed and analyzed; as a result several problems are issued. Methods to resolve the problems, to specify the attributes of logistics equipments and to represent the semantics among them using semantic web technology are proposed. This study could make it possible to examine the conformities of interfacing equipments automatically.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.226-229
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• 2006

Strengthening with externally post-tensioned CFRP strips is more effective in increasing load carrying capacity of existing structures as well as reducing crack width and deflection. This study developed concrete embedded anchorages system for externally post-tensioned CFRP strips, and carried out experimental study to verify anchoring performance quantitatively. Through experimental results, anchoring strength of concrete embedded anchorage were quantified into shear strength of anchor bolt, bearing strength of concrete at the front of anchor plate and bond strength between anchor plate and concrete surface. In addition, overall anchoring performances according to combination of each unit force are examined in this study.