• 한국습지학회지
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• 제17권4호
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• pp.436-446
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• 2015

본 연구에서는 한강, 낙동강, 금강, 영산강, 섬진강 등을 중심으로 신규 조성된 친수지구에 대한 이용 현황 조사 방안을 제안하고, 조사 결과를 토대로 성장 곡선 모형을 이용하여 총 357개 지구에 대한 2014년 이용수요를 예측하였다. 또한 친수지구가 위치한 지방자치체의 인구밀도와 수계별로 위치한 인구 100만 이상 도시와 친수지구 사이의 거리에 의한 영향을 검토하였다. 각 친수지구별로 로지스틱 모형과 곰페르츠 모형으로 추정한 결과를 RMSE와 MAPE 적합도를 이용하여 선택하였으며, 분석 결과 2014년 친수지구 이용수요는 한강 수계와 충청북도에서 상대적으로 활성화 된 것으로 나타났다. 인구밀도의 영향은 금강 수계를 제외하고는 비교적 미미한 것으로 보이며, 친수지구 이용에 대해서는 대도시 영향이 나타나긴 하나, 마찬가지로 다른 수계에 비해 금강 수계에서 대도시 영향이 큰 것으로 나타났다.

• 대한건축학회논문집:계획계
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• 제34권11호
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• pp.13-22
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• 2018

At the time when zero energy building is expected to be generalized, this study examines whether the investment in the passive element or the active element is more effective in terms of energy in the construction process of zero energy building. In other words, the effect of energy demand by passive element and the change of energy generation by active element are examined in terms of the same investment cost. The purpose of this study is to examine the change of energy demand by passive element and the change of energy generation by active element in zero energy building and to make reasonable investment decision by comparing energy with cost aspect. For this purpose, we selected the buildings to be subjected to energy simulation and derive the required energy amount and energy generation amount by using meteorological data of four regions in Korea. The change of energy demand and energy generation according to the change of application condition was derived. In order to compare and analyze the changes in energy demand and generation at the same cost standard through price survey and quotation of window and photovoltaic power generation equipment.

• 한국수산과학회지
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• 제41권2호
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• pp.134-139
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• 2008

To improve the oxygen-deficient water mass (ODW), the spatial and temporal variation in the water quality and characteristic of ODW occurrence were analyzed using yearly water quality data from 1989 to 2006 in Jinhae Bay, Korea. In addition, we estimated $ODW_{area},\;ODW_{vol.}$ and $ODW_R$ for Jinhae Bay. The overall water quality improved during the 2000s, based the annual variation in dissolved oxygen, chemical oxygen demand, etc. A cluster analysis classified Jinhae Bay into the southwestern, central, northern, and eastern regions. ODW occurred throughout the southwestern region in 1993 and 2002-2004, and the estimated $ODW_{vol.}$ was about $1.92km^3$. ODW did not occur in the eastern region because circulating seawater was exchanged in that part of Jinhae Bay. As ODW was generated every year in the southwestern region, this is the most polluted area in Jinhae Bay. The ODWR decreased in the northern region, showing that the water quality there has improved since a wastewater treatment plant began operating in 1994.

• 한국지리정보학회지
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• 제23권3호
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• pp.161-173
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• 2020

이 연구는 부산소방재난본부의 119 구급활동일지를 이용하여 부산의 구급서비스의 지역적 불균형을 조사하였다. 2017년 구급신고 자료를 집계구 단위로 취합하여 구급서비스의 수요(신고건수, 인구대비 신고건)와 공급(신고건수, 인구대비 신고건수, 현장도착시간의 평균·변동계수·이상치, 관할구역 외 출동건수)의 공간분포를 GIS 공간통계분석 중 핫스팟분석을 이용하여 분석하였다. 분석결과는 구급서비스의 수요와 공급 모두 집중적으로 나타나는 핫스팟지역과 콜드스팟지역이 명확하게 구분되었으며, 이는 부산 내 구급서비스의 수요 뿐 아니라 공급이 지역적으로 불균형함을 의미한다. 특히 원도심과 그 주변지역과 부산시 외곽지역에서의 구급수요 및 공급에서 극명한 차이를 보였다.

• 한국항해학회지
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• 제16권2호
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• pp.53-78
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• 1992

GMDSS-the Global Maritime Distress and Safety system which is utilizing the new technologies such as satellite communication system, DSC and NBCP-is effectuated not only by the amendment of SOLAS but also by the conference of RR and IMO's MSC, and will be the major factor of the variation of the demand and supply of Radio Operators. To cope with the GMDSS voluntarily, regulations relating to the radio installation, the posting of Radio Operators, the bounds of duty, etc. must be established and the demand and supply of Radio Operators which take charge of the system must be accomplished pertinently. In this study, the authors suggested some practical schemes to improve the effect of policy as follow. 1. The Ministry of Communication must supervise strictly the arrangement of Radio Operators, especially relating tot he legally qualified complement of Radio Station, and must review the official certification system to upgrade the quality of Radio Operators. 2. The Ministry of Communication must take overall charge of the qualitifications and technical standards of Radio Operators, the extent of their engagement, etc. which are provided by International Regulations. 3. Relating Administrations must cooperate with Shipping Companies in onboard-training to foster and ensure the manpower of Radio Operators. 4. Institutional devices to drive the resolute investment in education and training for mariners, especially for the ship's officers, must be prepared. 5. The Communication Administration and the Korea Maritime and Port Adminstration(KMPA) must cooperate mutually in the balance of the demand and supply of Radio Operators and use make their best to realize more harmonious policies on the demand and supply of manpower.

• 상하수도학회지
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• 제22권1호
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• pp.23-29
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• 2008

Throughout the analysis of field data from water distribution system, valid parameters were determined that can be included in the water service and design plan. This study investigates water consumption patterns to understand the variation of water-demand structures utilizing the pattern analysis of domestic purpose water. Water use data were collected by a public water resources management firm in Korea, Kwater, for 140 houses monitored during three years. Flow meters were installed at the faucet for drinking water, the shower booth, the laundry machine, bathroom sink, toilet, and garden faucet. Data was filtered using multiple physically meaningful criteria to improve analysis credibility. Mann Kendall and Spearman's Rho tests were used to carry out the analysis. Distinct factors of water consumption patterns can be determined for both increasing and decreasing trends of water use. Throughout the data analysis, the characterization of terms was classified and analyzed by the condition of the location of water-demand. Analysis of this data provide a physical basis for the parameter configuration of a reasonable design for a domestic water demand prediction model.

• 대한교통학회:학술대회논문집
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• 대한교통학회 2003년도 제43회 학술발표회논문집
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• pp.127-150
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• 2003

This research presents a novel application of static traffic assignment methods, but with a variable time value, for estimating the market share of a high-speed rail (HSR) in the NW-SE corridor of Korea which is currently served by the airline (AR), conventional rail (CR), and highway (HWY) modes. The proposed model employs the time-space network structure to capture the interrelations among all competing transportation modes, and to reflect their supply- and demand-sides constraints as well as interactions through properly formulated link-node structures. The embedded cost function for each network link offers the flexibility for incorporating all associated factors, such as travel time and fare, in the model computation, and enables the use of a distribution rather than a constant to represent the time-value variation among all transportation mode users. To realistically capture the tripmakers' value-of-time (VOT) along the target area, a novel method for VOT calibration has been developed with aggregate demand information and key system performance data from the target area. Under the assumption that intercity tripmakers often have nearly "perfect" travel information, one can solve the market share of each mode after operations of HSR for each O-D pair under the time-dependent demand with state-of-the-art traffic assignment. Aside from estimating new market share, this paper also investigated the impacts of HSR on other existing transportation modes.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1454-1470
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• 2014

This paper propose a new power conditioner topology with intelligent power management controller that integrates multiple renewable energy sources such as solar energy, wind energy and fuel cell energy with battery backup to make best use of their operating characteristics and obtain better reliability than that could be obtained by single renewable energy based power supply. The proposed embedded controller is programmed for maintaining a constant voltage at PCC, maximum power point tracking for solar PV panel and WTG and power flow control by regulating the reference currents of the controller on instantaneous basis based on the power delivered by the sources and load demand. Instantaneous variation in reference currents of the controller enhances the controller response as it accommodates the effect of continuously varying solar insolation and wind speed in the power management. The power conditioner uses a battery bank with embedded controller based online SOC estimation and battery charging system to suitably sink or source the input power based on the load demand. The simulation results of the proposed power management system for a standalone solar/WTG/fuel cell fed hybrid power supply with real time solar radiation and wind velocity data collected from solar centre, KEC for a sporadically varying load demand is presented in this paper and the results are encouraging in reliability and stability perspective.

• 산업경영시스템학회지
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• 제42권1호
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• pp.129-136
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• 2019

In this study, we proposed a model for forecasting power energy demand by investigating how outside temperature at a given time affected power consumption and. To this end, we analyzed the time series of power consumption in terms of the power spectrum and found the periodicities of one day and one week. With these periodicities, we investigated two time series of temperature and power consumption, and found, for a given hour, an approximate linear relation between temperature and power consumption. We adopted an exponential smoothing model to examine the effect of the linearity in forecasting the power demand. In particular, we adjusted the exponential smoothing model by using the variation of power consumption due to temperature change. In this way, the proposed model became a mixture of a time series model and a regression model. We demonstrated that the adjusted model outperformed the exponential smoothing model alone in terms of the mean relative percentage error and the root mean square error in the range of 3%~8% and 4kWh~27kWh, respectively. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric energy together with the outside temperature.

• 전기학회논문지
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• 제56권6호
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• pp.1064-1070
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• 2007

This paper presents a grid-interactive current controlled voltage source inverter (CCVSI) with uniterruptible power supply (UPS), which uses an inner current control loop (polarized ramp time (PRT)) and outer feedback control loops to improve grid power quality and UPS. To reduce the complexity, cost and number of power conversions, which results in higher efficiency, a single stage CCVSI is used. The operation of this system could be divided into the power quality control (PQC) state mode and the UPS state mode. In PQC mode, the system operated to compensate the reactive power demand by nonlinear load or variation in load. In UPS mode. the system is controlled to provide a sinusoidal voltage at the rated value for the load when the gird fail. To verify the proposed system, a comprehensive evaluation with theoretical analysis, simulation and experimental results for 1KVA load capacity is presented.