• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6830-6837
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• 2014

Since the advent of global warming and energy depletion, there has been great interest in eco-driving (energy-efficient driving). In this paper, a system is proposed to monitor the idle running of an engine and steady driving for a vehicle equipped with an ISG (Idling Stop & Go system). The system consists of a G/W device to acquire the vehicle operation data, a smartphone app for monitoring eco-driving and a server system. The main contribution of this paper is that it defines the integrated functions, the architecture and operation mechanisms of a system for monitoring eco-driving including the prohibition of running idle. The system enables the users to check the idling stop times, driving speeds, fuel savings, and $CO_2$ emissions, resulting in the driving style for eco-driving. The server system, which is a part of this system, provides OpenAPI-style web services for the storage and retrieval of car operation data, which facilitates the development of applications.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.432-438
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• 2017

The primary objective of the current work was to develop a standardized retrofit hull form capable of saving energy based on existing vessels. The bow shape of existing vessels was investigated, giving consideration to design draft and speed. Resistance performances were assessed for existing vessels according to operating conditions. Commercial CFD codes and model test materials were used for assessment of effective power. Three retrofit hull forms with minimum resistance were selected given real operating conditions. These vessels were named after customized ready-made hull forms to enable ship owners to make easier choices. The effective power of each vessel was estimated under real operating conditions. Subjects were operated with the lowest draft, and performance for retrofit No. 3 showed an 11-16% improvement in effective power at low speed ranges of 16-18 knots compared to existing vessels. When operated with a middle draft, performance for retrofit No. 3 showed a 6-11% improvement in effective power at low speed ranges compared to existing vessels. When operated with the highest draft, performance for all vessels showed little difference in effective power.

• Journal of Advanced Navigation Technology
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• v.19 no.3
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• pp.175-181
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• 2015

Method establishment needs for recent shortening the flight path, fuel reduction, reduction of the flight delay time, increase of the route capacity like as relieve congested airspace and solving future demand. However, As the existing conventional navigation systems is impossible to be resolved. Hereupon, SBAS has been developed with using the GNSS. ICAO has recommended that SBAS need to be operated with aircraft operation from 2025, korea is also developing KASS in accordance with the recommendation. In this paper, before the 2022 KASS will be completed, KASS can be expected using for flight test and inspection as analyzing KASS flight test and relative specifications.

• Solar Energy
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• v.10 no.1
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• pp.63-79
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• 1990

It has been recognized that a policy for supplying solar house and hot water production systems utilizing solar energy needs to be driven to save civilian comsuming energy or to develop alternative energy. However, the economic feasibility study of solar energy systems must be carried out before their practical use. The purpose of this study is to furnish information for supplying policy and enlightening users with the economic feasibility study of solar house and hot water production systems. Decision support systems are established to carry out economic analysis on solar systems more accurately. Therefore, computer simulation is carried out to analyze the performance of solar systems and also economic feasibility study by trial and error method is carried out. Fuel cost and additional cost for solar systems are estimated employing present worth concept and economic analysis has been conducted using the break-even point analysis method and life-cycle cost analysis method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.257-262
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• 2009

Elastic-Plastic structural analysis was performed to evaluate structural characteristic and integrity for rocket motor case of solid propulsion system. The structural analyses were compared and evaluated using the simplified 2-D axisymmetric model and 3-D full model for rocket motor case with torispherical dome type. And pre-tension load for bolt model was considered in structural analysis. The results of displacement and stress for the simplified 2-D axisymmetric model and 3-D full model were in an good agreement with each other. Therefore, the simplified 2-D axisymmetric model for rocket motor case was recommended to verify quickly the structural integrity and save the modeling and calculating time in initial design stage. Also, the structural characteristic and integrity for rocket motor case according to 5 dome types was evaluated to select the optimal dome shape.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.81-82
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• 2010

Emerging global economic growth and increasing demand for energy supply and demand imbalance and the excessive use of fossil fuels existing the rapidly increasing greenhouse gas emissions and resource depletion of global energy crisis is deepening. Accordingly, improvement of living conditions around and through the natural ecological preservation and the need for a comfortable life for the meeting the importance of energy management and consumption are emerging. Many in the field of architecture for energy-saving measures, and conducting research and verify green building energy ratings and low energy for the initial steps that can be verified from the Energy Performance of BIM(Building Information Model) technology development and commercialization of the building energy to predict the performance objectively, leverages technology in an existing building energy performance analysis and possibilities of BIM-based green building process presented. In this study, using BIM for existing building energy performance analysis of data collected through the objective and efficient management of the energy it consumes Mapping and Management Plan is to research on.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.327-327
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• 2010

자동차에서 실내음질은 구매결정 요소들 중의 하나로 그 중요성이 점차 증가하고 있다. 따라서 다양한 운전조건에서 운전자가 기대하는 실내음질의 기대 수준을 충족시켜야 한다. 소비자는 운전경험과 습관에 따라 기대하는 음질에 차이가 있고 소리에 대한 표현방식도 모호하기 때문에 이러한 주관적 특성을 하나의 통일된 표현으로 정의 하기가 어렵다. 그러나 지난 이십여 년 동안의 음질개발과 차량 실내소음 주관평가의 통계처리로 통일된 표현을 할 수 있었다. 나아가 심리음향학 및 신호처리기술의 발달과 꾸준한 음질연구결과로 소리특성을 객관적으로 나타내는 소리의 시각화가 가능하였으며, 운전자가 인식하는 주관평가와의 상관관계를 높여 차량의 대표적인 음질인자로 정량화하여 음질목표를 설정할 수 있었다. 실내소음의 구성은 엔진 투과음, 흡배기 소음, 바람 소음, 도로 기인 소음 등으로 다양하므로 소음원에 따라 음의 균형을 맞추어 조화로운 음질개발을 하는 것이 중요했다. 또한 차량 판매되는 지역에 따라 선호음이 상이하여 지역별 실내음질의 차별화가 필요했다. 궁극적으로는 운전자의 감성품질을 만족할 수 있도록 음을 제어하여 브랜드 사운드를 개발하고 있다. 이러한 실내음질을 달성하기 위한 방법으로 소음원과 전달경로에 대해 기여도를 분석하고, 경로를 구성하는 시스템 별로 세분화하여 시스템 목표를 설정하였다. 시스템 개발에 중요한 인자로 차량의 동강성 및 흡차음 성능을 들 수 있다. 특히 디젤차량의 비중이 큰 유럽업체의 차량의 동강성 및 흡차음 개발 능력은 높게 평가되고 있다. 이에 유럽의 부품전문회사가 가지고 있는 해석과 시험적인 개발 방법을 통하여 전달계 특성을 만족하기 위한 시스템의 동강성 및 흡차음 특성을 개발하고 있다. 차량음질 튜닝의 중요한 기법 중 하나로 흡배기 개발을 추진하고 있다. 친환경자동차인 하이브리드차량, 전기차량 및 연료전지차량의 경우 전기구동부품에서 발생하는 각종 이음 발생을 최소화 했다. 보행자를 보호하고 운전의 즐거움을 향상하기 위한 가상사운드 개발을 진행하고 있다. 회사 수익성 향상을 위한 원가절감 및 구조 경량화에 따른 음질악화와 연비 향상 및 배기가스 규제 강화로 고성능 고출력 엔진탑재에 따른 음질악화 요인을 극복해야 했다. 운전자의 청감은 차량의 운전성에 따라서도 크게 영향을 받게 되므로 엔진제어와 변속기제어를 통해 음질과 운전성이 조화를 이룰 수 있도록 개발하고 있다. 향후, 소음원에 따른 시스템 최적화 개발, 운전성과 음질 연계 개발과 친환경차량의 가상사운드 개발 등이 자동차 음질 개발의 중요한 이슈로 생각한다.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.512-520
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• 2011

This study was preformed to investigate the characteristics of the green drying system for utilizing heat wasted during carbonization process. The green drying system utilizing waste heat is one of environment-friendly equipments because it needs no other energies from fossil fuel and etc. In this study, waste heat from three kilns was collected by stainless connection pipe, and in the green drying system the temperature and humidity was hardly changed. Charcoal charecteristics as fixed carbon, refining degree, hardness, pH, calorific value, and charcoal yield were analyzed to investigate kiln performance due to installation of green drying system. As a result, the green dry system installation hardly affected the characteristics of charcoal. In conclusion, the green drying system can be applied to maximize the profit of the farm household income and contribute to reduce fossil energy.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.8-12
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• 2015

Non-esterified bio-diesel fuel saves cost by no esterified process and its performance was more similar to diesel oil than esterified bio-diesel fuel when the fuel blended 95% diesel oil and 5% it was used on diesel engine with electronic control system. A performance optimization is necessary for application of non-esterified bio-diesel fuel blended with diesel oil 95% on the latest diesel engine. In this study, test using fractional factorial design was accomplished at 25% and 50% partial load in order to evaluate influence of controllable 6 factors on responses such as specific fuel consumption, nitrogen oxides and coefficiency of variation of indicated mean effective pressure as basic experiment for performance optimization of this fuel. It is cleared that the injection timing and common rail pressure of 6 factors are mainly effective and its effect level is different according to load.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.310-315
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• 2017

Recently constructed ships are equipped with high efficiency propeller for low fuel consumption and comfortable operation. Based on the torsional vibration analysis of the shaft system of the high efficiency propeller, using the propeller damping method considering the characteristics of previous propeller designs, a considerable amount of analysis errors are found to be generated. These errors are expected to increase as the development of high efficiency vibration propellers continues. In this paper, errors in torsional vibration analysis, in accordance with various propeller damping methods, are reviewed. In addition, a propeller damping method suitable for use at present is suggested by reviewing the comparison results of analysis and measurement values according to the propeller damping methods for vessels adopting the high efficiency direct-coupled propeller with 10MW class.