In this study, we explore and catalog Korean astronomical heritages that are known to be preserved in foreign countries. We exclude old astronomical books from the catalog because they have been well studied and exist in numbers far too large for the scope of this study. From various documents and online collections, we find a total of 38 Korean astronomical heritages in six countries: 10, 11, and 14 items from the UK, France, and Japan, respectively, and 1 item from Germany, the US, and China each. These include items that are suspected to be of Chinese heritage and items of unconfirmed possession status. We divide the astronomical heritages primarily into two groups: time-keeping instruments (18 items) and astronomical charts (20 items). In this paper, we briefly review them according to country. We believe that this study provides a foundation for further detailed studies on each item, such as the Gujang-Cheonsang-Yeolcha-Bunya-Jido (舊藏天象列次分野之圖) preserved in the Library of Congress, United States.

PURPOSES : Sleeping hours are an critical factor that influences the lives of office workers. As for sleep characteristics, it is crucial to spend a lot of time; however, it is also important to ensure satisfactory sleep. This study attempted to analyze the factors affecting sleep in terms of time and satisfaction. METHODS : Sleep duration, which is a quantitative component of sleep, was composed of a continuous variable, and multiple regression analysis was employed. For the qualitative component of sleep, sleep time satisfaction was used, satisfaction was composed of binary type, and binary logistic regression analysis was used. Transportation characteristics, including personal and work characteristics, and other factors were used as independent variables. RESULTS : As a result of the analysis, various influencing variables were derived for both sleep duration and satisfaction. The higher the satisfaction with commuting time and commuting fee, age group, health level, and leisure time, the higher the sleeping hours and satisfaction. However, the higher the income or the choice of long-distance transportation, the lower both sleeping hours and satisfaction. Moreover, if they choose a car, have a high academic background, or have children, sleeping hours decrease, but satisfaction is high. Males, singles, and office workers with fewer than five employees had longer sleep hours but lower satisfaction. CONCLUSIONS : Commuting time and work characteristics have varying effects on sleep activity. Therefore, an alternative solution that can enhance both sleeping hours and sleeping hour satisfaction is proposed through the results of this study.

In this study, the applicability of biodiesel fuel was investigated as an hopeful alternative fuel for a compression ignition engine. The exhausted smoke emission of biodiesel fuel was reduced remarkably in comparison with commercial diesel fuel, that is, it was reduced approximately 64% at 2500 rpm, full load condition. And, torque, power and brake specific energy consumption rate did not showed significant differences. But, NOx emission of biodiesel fuel was slightly increased in comparison with the commercial diesel fuel. Generation of CO2 is considerably reduced by photosynthetic action in the course of growing biomass series plants, the material for biodiesel fuel.

LCD color filter용 염료로 1-amino-, 2-amino-, 1,4-diaminoanthraquinone과 methanesulfonyl chloride, benzenesulfonyl chloride를 각각 반응시켜 anthraquinonesulfonamide 화합물 1a, 1b, 2a, 2b, 3a, 3b를 합성하였다. 합성한 anthraquinonesulfonamide 화합물이 LCD color filter 용 염료로서의 적합한 특성을 갖는지 확인하기 위하여 분광특성, 용해도 특성 및 열적 안정성을 분석하였다. 분광특성으로 1a, 1b, 2a, 2b는 λmax가 395 ∼ 409 nm에서 나타나 노란색을 띄었다. 용해도 특성에서 2a와 2b는 1,4-dioxane 용매에서 3 w% 이상의 용해도를 보여 매우 우수한 결과를 나타내었다. 열적 안정성은 모든 anthraquinonesulfonamide가 200 ℃ 이상의 고온에서도 현저한 분해 없이 안정한 결과를 나타내었으며, 특히 2b와 3b는 240 ℃ 이상에서 도 중량의 95 % 이상을 유지하여 매우 우수한 열적 안정성을 보여준다.

The printing of nanomaterials onto certain substrates is one of the key technologies behind high-speed interconnection and high-performance electronic devices. For the printing of next-generation electronic devices, a printing process which can be applied to a flexible substrate is needed. A printing process on a flexible substrate requires a lowtemperature, non-vacuum process due to the physical properties of the substrate. In this study, we obtained well-ordered Ag nanowires using modified gravure printing techniques. Ag nanowires are synthesized by a silver nitrate (AgNO3) reduction process in an ethylene glycol solution. Ag nanowires were well aligned by hydrodynamic force on a micro-engraved Si substrate. With the three-dimensional structure of polydimethylsiloxane (PDMS), which has an inverse morphology relative to the micro-engraved Si substrate, the sub-micron alignment of Ag nanowires is possible. This technique can solve the performance problems associated with conventional organic materials. Also, given that this technique enables large-area printing, it has great applicability not only as a next-generation printing technology but also in a range of other fields.

The smoke emission of biodiesel fuel was reduced remarkably in comparison with diesel fuel, that is, it was reduced approximately 36% at 2000rpm, full load condition. And, power, torque and brake specific energy consumption showed no significant differences. However, NOx emission of biodiesel fuel was increased compared with commercial diesel fuel. Also, the effects of exhaust gas recirculation(EGR) to reduce the NOx emission has been investigated. It was found that simultaneous reduction of smoke and NOx was achieved with biodiesel fuel(20vol-%) and cooled EGR method(10∼15%).

• 현재 조사시 70%이상이 관리 불량 • 이로 인한 화재 발생시 소화기 작동 불능 • 초기 진압 실패ㅡ> 대형화재 • 막대한 피해 손실 발생 • 소화기 관리의 중요성 인식 • 자동화 소화기 관리 시스템 제작

In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for a direct injection diesel engine. It was tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenated blended fuel which has seven kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission have been investigated. Ethylene glycol mono-n-butyl ether(EGBE) contains oxygen component 27% in itself, and it is a kind of effective oxygenated fuel of mono-ether group that the smoke emission of EGBE is reduced remarkably compared with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in a diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and cooled EGR method.

In this paper, the effects of oxygen component in oxygenated additives blended fuels on the exhaust emissions have been investigated for direct injection diesel engine. It tested to estimate changes of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenated additives blended fuels which have four kinds of fuel and various mixed rates. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission and brake specific fuel consumption rate also have been investigated. The results of this study show that individual hydrocarbons as well as total hydrocarbon of oxygenated blended fuels are reduced remarkably compared with diesel fuel. It was found that simultaneous reduction of smoke and NOx emission was achieved with oxygenated blended fuels and cooled EGR metho

In developing new generation vehicles, the fuel cell hybrid vehicle has become more important as environmental standards become more stringent. This paper details the Fuel Cell Hybrid Radio Control Car (FCHRC) with proton exchange membrane fuel cell stack(75×55×65mm, 6V, 5A) and a secondary battery(7.4V, 2A) charged up by a solar cell(61mm x 110mm, 1.7V, 450mA). The design work of the FCHRC was made progress by CATIA modeling & assembling before manufacturing it. In this paper, we will focus on the automatic conversion of a power source between the PEMFC and the secondary battery, and finding the optimum conditions (temperature, humidity, airflow rate and hydrogen pressure) through thousands of performance tests in the humidity-temperature program controller. The purpose is that the models and data from the experiments we conducted will contribute to the ongoing development of the fuel cell hybrid car.

The Port treat 99.7% of freight for imports & exports in our country. So The Port is much accounted of the economy. Then the government and economy study about rasing port efficiency and productivity. But most of the studies are related with container terminal. Container is easy to treat. Because container is standardized. And it also is easy to implement to a system. But general terminal which treats bulk-cargo or general cargo is not. In this study, Stevedoring System applying PDA is developed by analyzing current system and business process. It is based on Web Service. So It is easy of access.

The Effects of cooled and hot EGR(exhaust gas recirculation) on the characteristics of smoke and NOx emission have been investigated using a single cylinder, water-cooled, four cycle, DI diesel engine at several loads and speeds. In this study, a manually controlled EGR system was installed on a agricultural diesel engine which was operated at various operating system. And, the effects of hot EGR and cooled EGR on smoke and NOx emission were compared. The results showed that cooled EGR method was more effective than hot EGR method on smoke and NOx emission.

본 논문에서는 철근콘크리트 연속보의 최적설계 문제를 다루었으며, 설계실무에서 사용하기 위한 GUI 시스템을 개발하였다. 최적설계 문제형성을 위해 목적함수로 콘크리트, 철근 그리고 거푸집의 경비함수로 취하였고, 설계변수는 보의 폭과 유효높이 그리고 철근비이다. 제약조건으로 강도, 사용성, 내구성 그리고 기하학적인 조건을 고려하였다. 이렇게 형성된 비선형 최적설계문제는 축차선형계획기법과 축차볼록계획기법을 사용하여 최적해를 구하였으며 그 효율성을 비교하였다. 또한 실제 설계실무에서 손쉽게 사용할 수 있도록 visual basic을 이용한 GUI 시스템을 개발하여 수치예를 통한 적용성을 보였다.

본 논문은 복합 적층구조의 최적설계에 있어서 유전알고리즘(GA)의 응용성을 보여준다. 설계점들의 최기집단이 확률론적 과정에 의해 무작위로 생성되고, 설계점들의 개선을 위해 자연선택과 적자생존의 원리가 적용되었다. 유전알고리즘의 범용성 및 신뢰성 검증을 위해 5가지 검증 함수를 고려하였으며, 수치예에서 연속형 및 정수형 그리고 이산형 설계변수를 동시에 갖는 복합 적층 캔틸레버보의 최소 중량 설계가 외부 벌칙함수가 부가된 유전알고리즘에 의해 수행되었다. 설계 문제는 강도, 변위 그리고 고유진동수 제약조건을 포함하면서 다차 비선형성으로 정식화 되었다. 수치예의 결과에 대한 비교분석을 통해 유전알고리즘 탐색 기법이 높은 범용성을 지니면서 양질의 최적해를 매우 효과적으로 찾게됨을 보였다.