• International Journal of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.71-82
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• 2020

Traffic accidents due to excessive speed frequently occur in places where traffic signal controllers are installed, places where sharp curves exist, or places where the traffic signal cycle does not match the current time. These traffic accidents cause economic loss due to the destruction of road facilities and structures, and cause a big problem of increasing the number of traffic accident deaths. When a traffic accident occurs, leaving a tire mark before or after a car crash, pre-collision speed of the car is calculated using the law of conservation of momentum or the skid mark formula. In the skip skid mark generated in ABS brake vehicles and the combshaped yaw mark generated by tire trace caused by lateral sliding, there is a difference of 30-40% in the reliability of the vehicle speed calculated by the smite mark. In this paper, we propose an algorithm that can improve the calculation reliability in vehicle speed by using skid marks in order to compensate for this problem. In addition, we present an intelligent speed calculation algorithm for traffic safety and a computer simulation in order to prevent traffic accidents by estimating the speed of a vehicle, using Skid marks, Yaw marks, and ABS brake characteristics and fuzzy rules.

• 대한지하수환경학회지
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• 제2권1호
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• pp.38-47
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• 1995

이 연구에서는 삼척탄전 내에 위치하는 폐탄광인 동해탄광을 대상으로 산성 광산폐수의 중화 처리를 위한 각종 기초자료를 제시하고자 하였다. 산성 광산폐수의 측정시기에 따른 변화양상을 관찰한 결과 갈 수기에는 각종 잠재적 유독성 원소들의 함량이 증가하며, pH가 하락하여 수질이 악화되는 경향을 보였다. 공업용 소석회는 처리효율 및 경제성을 고려할 경우 산성 광산폐수의 처리를 위한 최적의 중화제로 판단되며, 평형 모델링 결과 중화처리과정에서 Fe는 FeOOH의 형태로, Al은 Al(OH)$_3$, 의 형태로 침전되는 것으로 추정된다. GIS를 이용하여 동해탄광일대 산성 광산폐수 처리시설의 위치를 제시하였으며 수문학적 자료를 이용하여 최대강우량 및 첨두유량을 계산하였다.

• 한국정보통신학회논문지
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• 제17권6호
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• pp.1266-1272
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• 2013

본 연구에서는 WiBro 및 LTE방식을 이용한 재난안전무선통신망 설계에 필요한 링크 버짓을 계산하여 전국망 구축에 필요한 셀 수량을 파악하며, 그 결과에 대한 상호 비교를 통하여 경제적 관점에서의 효율적인 통신방식을 제시한다. 계산 결과, 전국망을 구축하는 데 있어서 WiBro방식은 LTE방식에 비해 상향링크에 대한 PAPR과 전송 방식차이 및 SINR차로 인해 동일 주파수 대역에서 두 배 이상 많은 셀이 필요한 것으로 나타난다. 이러한 결과를 근거로, 전국망 구축시 동일 대역을 이용할 경우 WiBro에 비해 LTE방식이 경제적인 면과 기술 및 시장 측면에서도 효율적이라고 판단된다.

• 대한전기학회논문지
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• 제37권5호
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• pp.272-281
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• 1988

The problem of optimal transmission system planning is to find the most economical locations and time of transmission line construction under the various constraints such as available rights-of-way, finances, the technical characteristics of power system, and the reliability criterion of power supply, and so on. In this paper the constraint of right-of-way is represented as a finite set of available rights-of-way. And the constructed for a unit period. The electrical constraints are represented in terms of line overload and steady state stability margin. And the reliability criterion is dealt with the suppression of failure cost and with single-contingency analysis. In general, the transmission planning problem requires integer solutions and its objective function is nonlinear. In this paper the objective function is defined as a sum of the present values of construction cost and the minimum operating cost of power system. The latter is represented as a sum of generation cost and failure cost considering the change of yearly load, economic dispatch, and the line contingency. For the calculation of operating cost linear programming is adopted on the base of DC load flow calculation, and for the optimization of main objective function nonlinear Branch-and-Bound algorithm is used. Finally, for improving the efficiency of B & B algorithm a new sensitivity analysis algorithm is proposed.

• 설비공학논문집
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• 제29권4호
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• pp.202-211
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• 2017

In this study, the exergy that can be reflected in the energetic and economic values was used to assess the heat tariff of a district heating (DH) system instead of the enthalpy. It is difficult to directly apply the exergy to the current heat-charge system because of the complicated calculation; therefore, the difference between the supply and return temperatures was converted to the exergy-temperature difference for the ease of the heat-amount calculation. As a result of the exergy analysis for a DH substation, the exergy-temperature difference did not affect the surrounding temperature and pressure loss. The supply temperature and the maximum difference between the supply temperature and the return temperature exerted the main effect on the exergy-temperature difference. The new heat charge of a DH user was slightly reduced in winter compared with the previous charge, but the heat charges in the other seasons are almost the same. It is concluded from the assessment of the heat tariff for which the exergy is used that this tariff is more feasible for both DH suppliers and consumers compared with enthalpy.

• 전기학회논문지
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• 제66권2호
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• pp.305-314
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• 2017

Most of the existing researches on systemwide optimization of generator maintenance scheduling do not consider the equivalent operating hours(EOHs) mainly due to the difficulties of calculating the EOHs of the CCGTs in the large scale system. In order to estimate the EOHs not only the operating hours but also the number of start-up/shutdown during the planning period should be estimated, which requires the mathematical model to incorporate the economic dispatch model and unit commitment model. The model is inherently modelled as a large scale mixed-integer nonlinear programming problem and the computation time increases exponentially and intractable as the system size grows. To make the problem tractable, this paper proposes an EOH calculation based on demand grouping by K-means clustering algorithm. Network congestion is also considered in order to improve the accuracy of EOH calculation. This proposed method is applied to the actual Korean electricity market and compared to other existing methods.

• 대한설비공학회지:설비저널
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• 제19권2호
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• pp.67-81
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• 1990

The objective of this is to develop a practical software package to calculate annual energy consumption of HVAC (Heating Ventilating, and Air Conditioning) System in a building. It can quickly estimate loads and energy consumption, and have a function of economic analysis through the estimation of operating cost. Techniques of save energy consumption used in a building are necessary from the stage of design process to operation. The single most significant task is on HVAC Systems. Their installation costs, and related operating costs have enormous influence upon initial and maintenance costs. HVAC designers and engineers now have a wide variety of software choices available, but only a few of them have been developed in this country and no source program has been disclosed. Neither load culculation nor estimation of energy consumption is systematically made by the domestic HVAC design firms. Even though computer improved over the years with a trend of large scale load calculation and system selection through simulaion, the utilization of software nowadays does not make good progress due to lack of working environment. Therefore, it is necessary to develop a practical software package with which load calculation can be made with ease and kind manner. This study concerns the development of a software package which makes it possible to design HVAC system and save energy consumption in operation. The algorithm used in this program is a Modified Bin Method widely known as a simplified energy analysis means.

• 수산경영론집
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• 제14권2호
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• pp.15-68
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• 1983

From the economic point of view the fishing port is the complex of installations on land, organized to serve the fishing fleet and its cargo, and is the main link in the production chain of all components of the fishing industry, with the aim of achieving the planned targets with the minimum cost. Fishing port investment decisions have had significant impact on the development aims of Korean fisheries. Fishing port investments in Korea are made mostly by public or semipublic port authorities. Such investments should be judged not purely on the basis of financial profitability but rather on the extent to which they serve the development aims of the fishing industry. This makes the economic appraisal process more complex and presents certain problems in correctly quantifying the economic costs and benefits of the fishing port projects. This study concentrates more on the theoretical economic appraisal models than on the purely financial aspects of fishing port investments and points out the difference between the two approaches. In the result, there is clearly an element of judgment as to whether or not a shadow price needs to be used in estimating economic benefits and costs. From this viewpoint, some attempts are made to provide definitions of the possible economic benefits and costs, and methods for estimating and evaluating them in Part III and IV. Especially queueing theory is applied in the calculation of economic benefits. When a project is contemplated and analysis shows it to Lave a positive NPV, one question that arises is whether it should be implemented now or delayed. In this paper, the first year rate of return method is regarded as a more concise way of solving the timing of investment, At the end of Part IV, risk analysis of fishing port investments is considered. It can be handled in a number of ways, ranging from informal judgment to complex statistical analyses involving large-scale computer models, This paper recommends that evaluators of fishing port investments use the sensitivity analysis indicating exactly how much NPV will change in response to a given change in an input variable, other things held constant. Decisions regarding the amount of capacity to provide must be made in fishing port investments. Providing too much service would involve excessive capital costs. On the other hand, not providing enough service capacity would cause the waiting line of fishing vessels to become excessively long at times. Therefore, in Part V, the optimal number of berths and berth productivity in fishing port are defined as follows: Minimize E(TC) ＝ E(WC)＋E(SC) The minimum of this function is the solution and that is the optimal number of berth and berth productivity in fishing port.

• 한국항만경제학회지
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• 제37권4호
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• pp.33-40
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• 2021

현재 해운·항만 산업은 급변하는 트랜드와 치열한 경쟁 속에서 살아남기 위해 항만물류자원의 확충 및 효율적인 운용을 통해 항만 처리능력을 향상시키기 위한 전략을 펼치고 있다. 항만의 처리능력 산정은 부두에 설치되는 하역장비에 의하여 결정되는 것으로 항만의 처리능력은 물류자원을 추가적으로 배치하거나 활용 중인 자원을 효율적으로 운용하는 등 다양한 방법을 통해 향상 시킬 수 있다. 하지만 물류자원의 추가 배치는 시간과 비용의 한계가 명확하기 때문에 단기간에 향상 효과를 기대하기 어렵다. 따라서 처리능력 향상을 위해서는 활용중인 자원에 대한 효율적인 운용 방법을 찾는 것이 실현성이 높다. 국내 항만들 역시 4차 산업혁명 기술의 발달에 따라 정보화, 디지털화를 적극적으로 추진하고 있다. 그러나 현재 하역 프로세스에서 Y/T 배정 대수 산정은 전문가의 경험에 따른 감각에 의존하고 있는 실정이며, 관련된 선행연구 또한 Y/T의 배차 또는 항만 전체의 필요 대수 산정에 초점을 두고 있다. 이에 본 연구는 입항 선박의 하역정보를 활용하여 Y/T 배정 대수에 영향을 미치는 요인을 분석하고 이를 바탕으로 군집분석, 회귀분석, DNN(Deep Neural Network : 심층신경망)모형을 활용하여 분석하였다.

• 한국화재소방학회논문지
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• 제29권1호
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• pp.73-79
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• 2015

스프링클러 설비의 설계방법은 크게 3가지로 분류한다. 가지관을 서로 연결하여 사다리형태로 배관을 설치하는 Grid형과 가지관은 연결하지 않고 교차배관만을 연결하는 Loop형 그리고 가장 일반적으로 사용되는 Tree형이 있다. 이 중 Grid형은 아주 간단한 것을 제외하고는 컴퓨터프로그램으로 마찰손실을 계산하여야 하지만 Loop형의 경우는 프로그램의 도움 없이 설계자가 직접 계산하여 마찰손실에 따른 필요압력과 소요유량을 산출할 수 있다. Loop형 설비의 경우 소화수 공급이 2방향으로 분리되어 마찰손실이 작아지고 헤드간 방출압력의 차이가 Tree형보다 작게 되어 살수분포가 우수하게 되며 작은 마찰손실에 의한 소구경의 배관을 사용하여 자재비와 인건비가 절감되므로 Loop형에 의한 스프링클러의 설계가 Tree형 설비에 비해 성능과 경제성에서 우수한 설계 방법이다. 하지만 Loop형 설비의 설계는 설계방법이 잘 알려져 있지 않아 거의 이루어지지 않고 있다. 본 논문에서는 Tree형 보다 우수한 Loop형 설비의 설계방법을 설명하여 많은 설계자가 성능과 경제면에서 우수한 Loop형 설계를 쉽게, 널리 사용하게 하고자 하였다.