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        검색결과 16

        1.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 청광 차단렌즈의 효과를 정량적으로 분석하는 방법을 새롭게 제시하고, 이를 시판하고 있는 기능성 렌즈에 적용하여 비교 분석함으로써 그 활용 가능성을 확인하고자 하였다. 방법 : 렌즈의 광투과율을 측정하고, 청광 차단 효율 함수를 적용하여 효율에 대한 정성적인 분석을 하였다. 또한 청광 차단 효율 결과를 적분하여 수치화하는 정량적인 분석 방법을 새롭게 도입하여, 시판중인 청색광차단 기능성 렌즈에 적용하여 비교분석하였다. 결과 : 정성적인 분석 방법을 일반렌즈, 코팅방법으로 제작된 2종의 렌즈와 착색방법으로 제작된 1종의 렌즈에 적용한 결과, 모든 렌즈는 단파장 영역의 빛을 차단하는 효과가 우수한 것으로 분석되었다. 하지만 정량적인 분석 방법에 의한 결과에서는 각 렌즈별 다소 차이가 있음을 확인하였다. 결론 : 다양해지는 디스플레이 장치 및 스마트폰의 광 특성이 날로 진화되고 변화되고 있으므로, 다양한 방법으로 광원과 광학제품에 대한 광특성 분석이 요구된다. 이에 따라, 본 연구에서 새롭게 도입한 정량적인 분석 방법이 효과적인 수단일 될 수 있는 가능성을 확인 하였다.
        4,000원
        2.
        2003.11 구독 인증기관 무료, 개인회원 유료
        Each method for economic evaluation has its own characteristics. Therefore adoption of each of them in evaluation production investment project results in many problems. Hence combination & modification of them are required to perform more accurate evaluation about investment project. This paper discuss evaluation method of investment projects expansion and replacement investment on each line or individual in the production. Generally investment evaluation method has add to a few method by Subsidiary means with use a especial method. And then in this paper, a Taguchi Techniques is presented, which may be effective to the facilities appraisal or improvement. We propose a decision model to incorporates the values assigned by a group of experts on different factors in production. Using this model, SN ratio of taguchi method for each of subjective factors as well as values of weights are used in this comprehensive method for reducing production rate in production management.
        3,000원
        3.
        2000.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 외부의 동하중에 의한 다층 지반-말뚝 상호작용계의 해석을 위한 동적 유한요소-경계요소 조합 주파수 응답해석 알고리즘을 개발하였다. 전체 상호작용계를 내부영역과 외부영역으로 나누고, 내부영역에 보요소를 도입하여 말뚝을 모형화 하고 평면변형률 요소로 모형화된 지반과 조합하였다. 말뚝머리 절점에 집중질량을 이용하여 상부구조물을 고려하므로써 전체 지반-말뚝 상호작용계의 내부영역을 형상화하였다. 외부영역에 동적 기본해를 이용한 경계요소 해석을 도입하고 유한요소로 구성된 내부영역과 조합하므로써 반무한체에 대한 방사조건을 만족시키고 내부의 복잡한 기하학적 성질과 다양한 물성의 고려가 가능한 수치해석 기법을 개발하였다. 개발된 지반-말뚝-구조물계의 상호작용 해석법에 대한 타당성을 알아보기 위해 다층반무한 지반에 근입되어진 말뚝에 조화하중을 가하여 동적 응답해석을 실시하고 기존의 연구결과 및 실험값과 비교 검증하였다. 또한 상호작용계의 주요 인자들의 변화를 통한 다양한 해석을 수행하므로써 다층 반무한 지반에 근입되어진 말뚝의 동적 특성을 고찰하였다.
        4,300원
        4.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        A model has been developed to predict natural ventilation in a single zone building with large openings. This study first presents pressure-based equations on natural ventilation, that include the combined effect of wind and thermal buoyancy. Moreover, the concept of neutral pressure level(NPL) is introduced to consider the two-way flow through a large opening. The total pressure differences across the opening and the NPL are calculated, and nonlinear equations are solved to find the zonal pressure to satisfy mass conservation. For this analysis, an iterative technique of successively approximating the zonal pressure is used. The results of applying this study model to several simple cases are as follows. When there is no wind and only the stack effect is caused, a one-way flow occurs in both the top and bottom openings in the case of two openings of equal-area, and a one-way flow occurs in the top opening; however, a two-way flow occurs in the bottom opening in the case of two openings of unequal-area. When there is a wind effect, regardless of whether the outside air temperature is lower or higher than the indoor air temperature, air flows into the room through the bottom opening and out of the room through the top opening. As the wind velocity increases, the wind effect appears to be more influential than the stack effect owing to the temperature difference.
        5.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        Korean sixth industrialization policy is similar to that of Japanese such as goal of policy, setup and promotion method of specific policy projects as it benchmarked a Japanese case. First of all, the certification systems of both countries, the most representative policy, are very alike that the governments officially certificate management bodies, prepare the ground for continuous sixth industrialization, devide intermediate support organization into the central unit and regional unit, and have the function of support and control of sixth industrialization management bodies. Furthermore, both countries create fund for sixth industrialization as an investment support policy, and push forward with the phased support policy businesses such as individual support and connected support for management bodies. However, there are some differences between certification systems of both countries such as process-oriented or result-oriented for certification, subtle differences of the role in support organization, and the range and rate of support.
        6.
        2014.09 KCI 등재 서비스 종료(열람 제한)
        For the purpose of drawing a representative type of utilizing idle farmlands, this study collected and analyzed newspaper articles about cases of utilizing idle farmlands in the past decade using Internet search engines. Prior to this, it clarified a concept of idle farmlands to raise accuracy of searching articles, and selected NAVER as a search engine. It set "idle farmland", "abandoned land", and "utilizing" as basic search words in search option, and also set search period from 1st of January in 2004 to 31st of December in 2013. This study primarily searched 1,593 articles, and extracted 165 articles excluding overlapped and unrelated articles. Furthermore, it investigated extracted articles by date, media, headline, content of use, region(province), particular area(city and country), main agent, item and keyword 1, 2, 3 for proper use. This study also examined frequencies by year according to indoor and outdoor environment as well as regional differences through frequencies by regional groups and chronology. Furthermore, it drew a diagram of frequency flow of keyword 2, 3 with each keyword 1 as the central figure in order to draw various types of using idle farmlands. Through the diagrams, this study drew 9 using types such as (1) community service. agriculture type, (2) high income. agriculture type, (3) sightseeing. landscape. agriculture type, (4) livestock. agriculture type, (5) weekend farm type, (6) high income. woodland type, (7) ecology. landscape. woodland type, (8) agricultural work-study type, (9) ecological environment type.
        7.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        Self-sufficiency rate of food in South Korea is almost at the lowest level among OECD countries, and the decrease tend of farmland is expected to be continued. In this situation, the government has been revised the target self-sufficiency rate of food, and carried forward various policies in order to achieve it. One of those policies is the restoration business of idle farmland which is planned to carry forward after 2015. This study set up indicators evaluating effective use of idle farmland, and tried to apply in the field before carrying forward restoration business. The result of this study may be summarized as follows. First of all, it reset an evaluation indicator that was based on the evaluation indicator developed in order to set application directions of idle farmland. Next, it selected 30 idle farmlands with reset evaluation indicator among 11,635 which were inspected nationwide in 2012. Before applying indicator, it measured the condition of recycling such as accessibility of farmland, condition of irrigation and drainage system, land state, and surroundings by field investigation. Then, it calculated composite score in each target area through applying indicators, and verified the indicator by comparing calculated result with the one which was decided from field investigation. Finally, it carried out field investigation, correct and upgrade some problems of the standard of score calculation that was found during applying previously set evaluation indicator to target area, and established the final standard of calculation for evaluation indicator.
        8.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        Self-sufficiency rate of food in South Korea is almost at the lowest level among OECD countries, and the decrease tend of farmland is expected to be continued. In this situation, Korea experienced a rapid change in the international price of grain due to changes in amount of grain production and food weaponization. It also started to reinforce the appropriateness of maintenance of farmland above certain standard. As one of policy means for this situation, this study selected "the use of idle farmland" as a subject, and started to consider the way to suggest the policy projects using idle farmland. The result of this study is summarized as follows. Firstly, this study defined the meaning of idle farmland, and set up the scope of idle farmland needed to this study. Secondly, this study analyzed the domestic major policy projects with prevention function of idle farmland as well as the policy projects related to idle farmland. It also investigated "recycling measures of idle farmland" that is recently promoted in Japan, and deducted the direction for developing a new model. Lastly, It suggested 9 policy project models that are finally able to use idle farmland. Suggested models are designed to access from various directions. This study suggested contents, entity, target and characteristics of projects in order to set up proper directions in promoting policy projects using idle farmland.
        9.
        2014.02 KCI 등재 서비스 종료(열람 제한)
        A ventilation model was developed for predicting the air change per hour(ACH) in buildings and the airflow rates between zones of a multi-room building. In this model, the important parameters used in the calculation of airflow are wind velocity, wind direction, terrain effect, shielding effect by surrounding buildings, the effect of the window type and insect screening, etc. Also, the resulting set of mass balance equations required for the process of calculation of airflow rates are solved using a Conte-De Boor method. When this model was applied to the building which had been tested by Chandra et al.(1983), the comparison of predicted results by this study with measured results by Chandra et al. indicated that their variations were within -10%~+12%. Also, this model was applied to a building with five zones. As a result, when the wind velocity and direction did not change, terrain characteristics influenced the largest and window types influenced the least on building ventilation among terrain characteristics, local shieldings, and window types. Except for easterly and westerly winds, the ACH increased depending on wind velocity. The wind direction had influence on the airflow rates and directions through openings in building. Thus, this model can be available for predicting the airflow rates within buildings, and the results of this study can be useful for the quantification of airflow that is essential to the research of indoor air quality(temperature, humidity, or contaminant concentration) as well as to the design of building with high energy efficiency.
        10.
        2010.02 KCI 등재 서비스 종료(열람 제한)
        The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. A sensitivity analysis of indoor environment factors was carried out to grasp influences along with changes of atmospheric conditions. An integrated multizone model was used to predict these sensitivities. This model was applied to an apartment with six zones. Airflow rates are influenced very seriously by changes of wind direct or wind velocity, but are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air temperatures are influenced very directly by changes of outdoor air temperature, but are influenced very slightly by wind direction or wind velocity and are not influenced at all by changes of outdoor air humidity or contaminant concentration. Indoor air humidities are influenced very directly by changes of outdoor air humidity, but are not influenced at all by changes of outdoor air contaminant concentration and have little or no influence by changes of wind direction, wind velocity, or outdoor air temperature. Indoor air contaminant concentrations are influenced very seriously by changes of wind direct or wind velocity, but are influenced somewhat by changes of outdoor air contaminant concentration and are influenced very slightly by changes of outdoor air temperature and are not influenced at all by changes of outdoor air humidity.
        11.
        2008.09 KCI 등재 서비스 종료(열람 제한)
        Interior space in most buildings is divided into several zones. The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. An integrated multizone model to predict these environmental factors simultaneously was developed. Also, a computer program for this model was written by the language of VISUAL BASIC. The proposed model was applied to a apartment with five rooms that had been tested by Chung11). Comparison of predicted results by this study with measured results by Chung showed that their variations were within 14% for airflow rates, 1% for temperatures, 12% for humidities, and 5% for concentrations. It was seen that the opening operation schedule of building has a significant effect on the air moisture and contaminant removal. Thus, this model may be available for predicting the indoor air environment and may be contributed to design the ventilation plan for controling of indoor air quality.
        15.
        1998.12 KCI 등재 서비스 종료(열람 제한)
        The well-mixed room model has been traditionally used to predict the concentrations of contaminants in indoor environments. However, this is inappropriate because the flow fields in many indoor environments distribute contaminants non-uniformly, due to imperfect air mixing. Thus, some means used to describe an imperfectly mixed room are needed. The simplest model that accounts for imperfect air mixing is a two-zone model. Therefore, this study on development of computer program for the two-zone model is carried out to propose techniques of estimating the concentration of contaminants in the room. To do this, an important consideration is to divide a room into two-zone, i.e. the lower and upper zone assuming that the air and contaminants are well mixed within each zone. And between the zones the air recirculation is characterized through the air exchange parameter. By this basic assumption, the equations for the conservation of mass are derived for each zone. These equations are solved by using the computational technique. The language used to develope the program is a VISUAL BASIC. The value of air exchange coefficient(f_12) is the most difficult to forecast when the concentrations of contaminants in an imperfectly mixed room are estimated by the two-zone model. But, as the value of f_12 increases, the air exchange between each zone increases. When the value of f_l2, is approximately 15, the concentrations in both zone approach each other, and the entire room may be approximately treated as a single well-mixed room. Therefore, this study is available for designing of the ventilation to improve the air quality of indoor environments. Also, the two-zone model produces the theoretical base which may be extended to the theory for the multi-zone model, that will be contributed to estimate the air pollution in large enclosures, such as shopping malls, atria buildings, airport terminals, and covered sports stadia.
        16.
        1997.12 KCI 등재 서비스 종료(열람 제한)
        A study on ventilation design using the spreadsheet model is carried out to propose means of available design. A sample of complex ventilation system in the non-standard condition is used to illustrate this spreadsheet model. In developing the spreadsheet model, this study has attempted to it general by using computional equations and design parameters that can be readily applied to any spreadsheet software. Also, most design data is contained in the spreadsheet template. This template provides the same design information as the ACGIH worksheet, and operates quickly and efficiently, and is flexible enough to use under different conditions. spreadsheet model allows the ventilation engineer to design quickly and accurately the ventilation system, without spending too much effort in the design process. By storing on computer and diskette, the design data computed finally can be used as a permanent record of specific ventilation system, and because of flexibility to be able to design over and over again while making only slight changes to the input data, the spreadsheet model is used availably to accomplish the design optimazation by redesign and troubleshooting by review from field measurements. Also, the spreadsheet model is available for designing ventilation system under different condition or evaluating existing system or design drawing, because changes in the layout or formulae can be readily made to fit the needs of the designer.