• Environmental Engineering Research
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• v.19 no.1
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• pp.47-57
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• 2014

The aim of this paper was to study the effect of five different waste combinations (C/N 15, C/N 20, C/N 25, C/N 30, and control) of sewage sludge coupled with sawdust and cattle manure in a pilot scale rotary drum reactor, during 20 days of the composting process. Our results showed that C/N 30 possesses a higher temperature regime with higher % reduction in moisture content, total organic carbon, soluble biochemical oxygen demand and chemical oxygen demand; and higher % gain in total nitrogen and phosphorus at the end of the composting period implying the total amount of biodegradable organic material is stabilized. In addition, $CO_2$ evolution and oxygen uptake rate decreased during the process, reflecting the stable behavior of the final compost. A Solvita maturity index of 8 indicated that the compost was stable and ready for usage as a soil conditioner. The results indicated that composting can be an alternate technology for the management of sewage sludge disposal.

• Asian Journal of Business Environment
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• v.2 no.2
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• pp.23-26
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• 2012

Purpose - The study on the consumption structure of urban residents can help us to understand demand law and to grasp the changing consumption trend of people. Consumption structure is an important indicator reflecting the people's living standard. It is of realistic significance to study urban consumption structure. Research data and methodology - This study is carried out with data connected with urban residents from Shandong Statistical Yearbook for the period 2000-2010 analyzing eight commodity groups. The almost ideal demand system (AIDS) is one of the important models related to consumption structure. Results - This paper shows that firstly gives a brief introduction to AIDS. Then it makes an empirical analysis on the urban residents' consumption structure in Shandong province, China on the basis of AIDS model. Conclusions - the authorities are supposed to control the prices of HC, Foodstuff and Housing and encourage the consumption of HC, Housing, EE accordingly. At the same time, local government should increase the supply of goods connected with housing, HA, HC, and EE so as to attract more consumption from the urban residents in Shandong.

• Journal of Korean Society of Transportation
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• v.4 no.2
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• pp.15-35
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• 1986

As the population of persons and automobiles rapidly grows, parking problems also grow in large cities of Korea. The purpose of this paper is to first grasp the status of parking facilities and characteristics in large cities of Korea; and introduce new directions of CBD parking policies in north America cities: and finally recommend the adequate parking management strategies and tactics for improving parking problems in Korea. For this purpose, field survey for parking inventories, patrol survey for parking usage as observed demand and drive interview survey for parking behavior were conducted. Compared with the parking characteristics and polices of foreign cities, many differences of characteristics were found, and existing parking management policies, which should be improved, were identified. Five categories of parking management strategies were set on; a) Reasonable control of CBD parking demand, b) securing of the public parking facilities c) Promotion of privately operated parking facilities d) expansion of financial resources for parking facilities construction and e) Improvement of existing parking management system. And actural seventeen tactics to attain the above strategies were recommended.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2490-2495
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• 2005

The scheduling of plant should be determined based on the product demands correctly forecasted by reasonable methods. However, because most existing forecasting packages need user's knowledge about forecasting, it has been hard for plant engineers without forecasting knowledge to apply forecasted demands to scheduling. Therefore, a forecasting module has been developed for plant engineers without forecasting knowledge. In this study, for the development of the forecasting module, an automatic method using the ARIMA model that is framed from the modified Box-Jenkins process is proposed. And a new method for safety inventory determination is proposed to reduce the penalty cost by forecasting errors. Finally, using the two proposed methods, the web-based automatic module has been developed.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.10
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• pp.1462-1470
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• 1989

This paper aims at investigating the Demand Assigned Multiple Access(DAMA) system for the packet-switched Satellite Communication. An onboard processor of the multisport beam satellite incorporates the ground controller to macimize the packet transmissions for each slot. 'Request Following' trnasmission mode is introduced as a transmission strategy of ground station under the control of its zone controller. The combined scheme of reservation channel access and contention channel access was proposed by Lee & Mark[3] for improving the Delay-Throughput performance. Our scheme provides less communication delay of approximately max. 200msec for achieving the corresponding throughput than the Lee & Mark's work does. Delay versus Throughput curves as well as Delay versus Traffic parameter curves are obtained. Numerical results obtained through the analysis and by the computer simulation show that the proposed scheme provides the low average packer delay even under the condition that the number of transponders (M)is below the half of the number of zones(N).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.10
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• pp.672-676
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• 2017

Electrical energy is playing an increasingly vital role as the primary energy source in everyday life. With the increase in electric power consumption, power facilities are under an increasing stress and must operate at a high capacity. Consequently, the demand for electric power cables in power transmission and distribution lines is rapidly increasing. Underground distribution lines have been steadily replacing the aboveground lines owing to the increase in electric power demand and the need to increase the supply voltage. In addition to line damage, worker safety is of primary concern in this type of underground infrastructure. In this study, to improve the safety of workers dealing with underground transmission lines, we analyzed the electromagnetic field generated around the distribution line and determined the basic criteria for developing a device that can detect a live underground line.

• Earthquakes and Structures
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• v.15 no.2
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• pp.203-214
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• 2018

Deflection control in tall buildings is a challenging issue. Connecting of the towers is an interesting idea for architects as well as structural engineers. In this paper, two reinforced concrete core-wall towers are connected by a truss bridge with buckling restrained braces. The buildings are 40 and 60-story. The effect of the location of the bridge is investigated. Response spectrum analysis of the linear models is used to obtain the design demands and the systems are designed according to the reliable codes. Then, nonlinear time history analysis at maximum considered earthquake is performed to assess the seismic responses of the systems subjected to far-field and near-field record sets. Fiber elements are used for the reinforced concrete walls. On average, the inter-story drift ratio demand will be minimized when the bridge is approximately located at a height equal to 0.825 times the total height of the building. Besides, because of whipping effects, maximum roof acceleration demand is approximately two times the peak ground acceleration. Plasticity extends near the base and also in major areas of the walls subjected to the seismic loads.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.529-530
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• 2015

스마트그리드 환경에서 증가하는 에너지 수요에 대응하기 위하여 수요 반응(Demand response, DR) 프로그램에 대한 연구가 활발히 진행 중에 있다. 특히, 전력 분야에서는 공급측 자원과 수요측 자원을 효율적으로 운영하기 위하여 수요 반응에 기반한 마이크로그리드 운영 기술이 요구되며, 추후 마이크로그리드의 실 시스템에 많은 도입이 예상된다. 본 논문에서는 TOU(Time-of-use)와 DLC(Direct load control)에 기반한 마이크로그리드의 최적 운영계획을 수립하고, 시뮬레이션을 통하여 제안된 수리적 모델의 타당성을 검토하고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.6
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• pp.266-271
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• 2000

The electric power industries are moving from the conventional monopolistic or vertically integrated environments to deregulated and competitive environments, where each participant is concerned with profit maximization rather than system-wide costs minimization. Consequently, the conventional least-cost approaches for the generation resource schedule can not exactly handle real-world situations. This paper presents a game theory application for analyzing power transactions and market design in a deregulated energy marketplace, where the market participants determine the net profits through the optimal bidding strategies. The demand elasticity of the energy price is considered for the realistic modeling of the deregulated marketplace.

• Journal of the Korean Professional Engineers Association
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• v.38 no.4
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• pp.7-9
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• 2005

The recent speculation fever in Kangnam and its southern vicnity of Seoul resulted in surging apartment prices. The government is determined to employ more effective anti-speculation policy measures to control the property speculative demand. The Government plans to implement support measures to discourage people from owning multiple homes by reinforcing tax measures. To meet the increasing demand for more large-sized apartments in Seoul, the Government may allow to build more large sized units. By the end of August, 'a comprehensive package tool of real estate policy measures' ,as a real estate controlling guidelines, is scheduled to be presented by the Government. We hope that the package tool will stabilize housing market more effectively and enhance the national economy.