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        검색결과 146

        22.
        2020.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In a previous paper, ambient vibration tests were conducted on a cable stayed bridge with resilient-friction base isolation systems (R-FBI) to extract the dynamic characteristics of the bridge and compare the results with a seismic analysis model. In this paper, a nonlinear seismic analysis model was established for analysis of the bridge to compare the difference in seismic responses between nonlinear time history analysis and multi-mode spectral analysis methods in the seismic design phase of cable supported bridges. Through these studies, it was confirmed that the seismic design procedures of the “Korean Highway Bridge Design Code (Limit State Design) for Cable Supported Bridges” is not suitable for cable supported bridges installed with R-FBI. Therefore, to reflect the actual dynamic characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure is proposed that applies the seismic analysis method differently depending on the seismic isolation effect of the R-FBI for each seismic performance level.
        4,000원
        23.
        2020.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a field bridge test was conducted to find the dynamic properties of cable supported bridges with resilient-friction base isolation systems (R-FBI). Various ambient vibration tests were performed to estimate dynamic properties of a test bridge using trucks in a non-transportation state before opening of the bridge and by ordinary traffic loadings about one year later after opening of the bridge. The dynamic properties found from the results of the tests were compared with an analysis model. From the result of the ambient vibration tests of the cable supported bridge with R-FBI, it was confirmed that the dynamic properties were sensitive to the stiffness of the R-FBI in the bridge, and the seismic analysis model of the test bridge using the effective stiffness of the R-FBI was insufficient for reflecting the dynamic behavior of the bridge. In the case of cable supported bridges, the seismic design must follow the “Korean Highway Bridge Design Code (Limit State Design) for Cable supported bridges.” Therefore, in order to reflect the actual behavior characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure should be proposed.
        4,200원
        24.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 PGA 정규 투어 남자프로골프대회에 자원봉사자로 참석한 대학생들의 참여 만족과 불만족에 대한 귀납적 분석 방법을 통하여 내용을 분석 후 결과를 도출하였다. 본 연구의 대상자는 2019년 “2019 더 CJ컵@나인브릿지 골프대회에 자원봉사자로 참여한 대학생을 대상으로 실시하였으며, 300명의 응답자 중 설문내용이 충실하지 못하다고 판단되는 76부를 제외한 224부를 내용분석 하였다. 먼저 참여 만족의 전체 세부영역인 408개의 원자료를 중심으로 2차 귀납적 범주분석을 실시하여 전체 10개의 세부영역과 5개의 일반영역으로 범주화하였다. 구체적으로 살펴보면, 첫째, “골프대회 경험만족”은 골프대회, 골프정보, 골프장으로 구분되었다. 둘째, “선수만족”은 직접관람, 유명선수로 구분되었으며, 셋째, “환경만족”은 장소만족, 시설만족으로 구분되었고, 넷째, “참여만족”은 봉사만족, 유능감 만족으로 구분 되었다. 마지막으로 “대인관계 만족”은 세부영역과 동일하게 적용하여 구분하였다. 참여 불만족의 경우 전체 세부영역인 369개의 원자료를 중심으로 2차 귀납적 범주분석을 실시하여 전체 10개의 세부영역과 3개의 일반영역으로 범주화하였다. 구체적으로 살펴보면, 첫째, “대회운영 시스템 불만족”은 세부적으로 업무 체계 불만, 운영 체계 불만, 관리 체계 불만, 전달 체계 불만으로 구분되었다. 둘째, “자원봉사 처우 불만족”은 자원봉사 처우 불만, 업무과다 불만, 근무시간 불만으로 구분되었으며, 셋째, “자원봉사 복지 불만족”은 식음료 불만, 복장불만, 부대시설 불만으로 구분되었다.
        5,100원
        25.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        When domestic sewage and rainwater runoff are discharged into a single sewer pipe, it is called a “combined sewer system.” The sewage design standards in Korea specify the flow velocity based only on the volume of rainfall; therefore, sedimentation occurs on non-rainy days owing to the reduced flow rate and velocity. This sedimentation reduces the discharge capacity, causes unpleasant odors, and exacerbates the problem of combined sewer overflow concentration. To address this problem, the amount of sewage on non-rainy days, not just the volume of rainfall, should also be considered. There are various theories on sedimentation in sewer movement. This study introduces a self-cleansing velocity based on tractive force theory. By applying a self-cleansing velocity equivalent to the critical shear stress of a sand particle, sedimentation can be reduced on non-rainy days. The amount of sewage changes according to the water use pattern of citizens. The design hourly maximum wastewater flow was considered as a representative value, and the velocity of this flow should be more than the self-cleansing velocity. This design method requires a steeper gradient than existing design criteria. Therefore, the existing sewer pipelines need to be improved and repaired accordingly. In this study, five types of improvement and repair methods that can maximize the use of existing pipelines and minimize the depth of excavation are proposed. The key technologies utilized are trenchless sewer rehabilitation and complex cross-section pipes. Trenchless sewer rehabilitation is a popular sewage repair method. However, it is complex because the cross-section pipes do not have a universal design and require continuous research and development. In an old metropolis with a combined sewer system, it is difficult to carry out excavation work; hence, the methods presented in this study may be useful in the future.
        4,000원
        26.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The number of complaints of odor in urban area has been increased due to mixed industrial areas of odor-related factories and municipal waste treatment odor-producing facilities located in adjacent residential regions. In this study, the characteristics of odor were reviewed according to two types of complaint from regions in Incheon area. In this study, the characteristics of odor were reviewed in two patterns of odor complaints in Incheon area such as the complaints are maintained high continuously and are increased in recent period. International city with largescale residential areas with the environmental facilities and redevelopment of residential regions with the adjacent industrial complexes and other odor emission sources were analyzed. Based on these characteristics, the odor management measures of major odor generating sources in order to improve urban environment were discussed with reducing odor complaints effectively.
        4,000원
        28.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        직류전동기는 속도제어가 간단하고, 출력 토크특성이 우수한 장점으로 윈치나 카고 펌프 모터 등으로 선박에서 많이 사용되었으며, 전기추진선박이 도입된 초기에는 선박용 추진전동기로도 적용되었다. 하지만 브러시와 정류기와 같은 기계적 정류장치의 단점으로 인해 최근에는 직류전동기와 전기적인 특성은 매우 유사하지만 기계적인 정류장치를 설치하지 않고 반도체 소자를 이용한 전자적인 정류장치를 사용하는 브러시리스 직류전동기의 사용이 증가하고 있다. 기존의 브러시리스 직류전동기를 구동하기 위한 인버터 시스템은 2 상여자방식을 사용하므로 역기전력파형이 사다리꼴모양으로 되며, 이로인해 전류가 흐르는 권선이 바뀌는 상전류 전환 구간에서 고조파와 토크리플이 발생하게 된다. 이러한 고조파와 토크리플을 저감하기 위한 다양한 방안이 연구되어 발표되었으며, 본 연구에서는 전력분 석프로그램을 이용하여 브러시리스 직류전동기의 구동회로에 비례적분 속도전류제어기 알고리즘을 구현한 Cascaded H-Bridge 멀티레벨 인버터를 적용하였다. 모델링한 브러시리스 직류전동기의 시뮬레이션을 통해 제안하는 전동기의 구동방식을 적용하는 경우에 기존의 구동방식에 비해 전동기 입력측 전압파형 개선과 고조파 및 토크리플이 현저히 저감되는 결과를 확인할 수 있었다.
        4,000원
        29.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examines the domestic and international bulletproof test standards of armor and plate which are supplied to the domestic market. In addition, improvements and suggestions for the test standard were presented. Experiments were conducted to clarify the distances to the edge, the difference between ammunition makers, and the position of the impact point of the bulletproof plate, which have been discussed in the conventional bulletproof test. As a result of the study, it was confirmed that the bulletproof performance is excellent as the distance from the edge increases. Next, performance differences between ammunition makers were not found. Finally, plates should be applied to the US ESAPI test specification to provide a clear and reproducible test method.
        4,000원
        32.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고염식식습관은 다양한 질병을 일으키고 공중보건을 위협할 수 있다. 그 동안 고염식식습관을 통제하기 위한 다양한 시도가 이루어져 왔으나 건강커뮤니케이션을 통해 고염식식습관을 변화시킬 수 있는지에 대한 연구는 아직 이루어지지 못하였다. 본 연구는 고염식의위험성과 식습관의 통제가능성에 대한 인식이 고염식식습관을 얼마나 예측하는지를 검토함으로써 식습관 개선 교육을 위한 시 사점을 찾고자 하였다. 이러한 연구목적을 달성하기 위해 보호동기 이론의 하위요인인심각성, 취약성, 효율성, 효능 및 행동 경향을 측정하기 위한 설문지를 개발하였으며 설 문지를 충남소재 대학의 대학생들과 그들의 가족을 대상 으로 배포하였다. 설문결과를 SPSS프로그램으로 분석한 결과를 보면 다음과 같다. 첫째, 청년층은 장년층보다 나 트륨섭취가 더 많았다. 둘째, 상관관계분석에서 장년층은 고염식으로 인한 위험에 취약하다는 것을 알고 있지만 고 염식을 억제할 수 있다고 확신할 때 까지는 식습관을 바꾸지 않는다. 셋째, 구조모델분석에 따르면 대처지각이 높을수록 고염식식습관의 경향성이 낮아지는 경향을 보인다. 이 결과는 고염식식습관을 줄이기 위해서는 실행 가능한 정보를 제공하고 저염식을 하였을 때 어떤 변화가 발생하는지를 인식 시킴으로써 대처지각을 높이는 방안이 더 효과적임을 시사한다.
        4,000원
        34.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to suggest the methodology to improve to estimate back-calculated fish growth parameters using weighted average. It is to contribute to correct errors in the calculation of back-calculated growth equation with unequal numbers of sample by age. If the numbers of sample were evenly collected by age, each back-calculated length at age was equal between arithmetic and weighted averages. However, most samples cannot be evenly collected by age in reality because of different catchability by fishing gear and limitation of environment condition. Therefore, the estimation of back-calculated length by weighted average method is essential to calculate growth parameters. There were some published growth equations from back-calculated length using a simple arithmetic average with different numbers of samples by age when searching for back-calculated growth equations from 91 relevant papers. In this study, the process of deriving growth equation was investigated and two different average calculations were applied to a fish growth equation, for example of Acheilognathus signifer. Growth parameters, such as L∞, k and t0, were estimated from two different back-calculated averages and the growth equations were compared with growth performance index. Based on the correction of back-calculated length using weighted average by age, the changes by female and male were -14.19% and -5.23% for L∞, and 59.28% and 18.91% for k, respectively. The corrected growth performance index by weighted average improved at 7.05% and 2.46% by female and male, respectively, compared to the arithmetic averages.
        4,000원
        37.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to consider application and evaluation of value and class of domestic wetland, we investigated 146 wetlands located Gyeongsangnam-do using Rapid Assessment Method (RAM). We utilized Self-Organizing-Map (SOM) to analysis relationship between evaluation index and land coverage ratio surrounding wetland. Among total 8 evaluation index, ‘Fish and herptile habitat’ and ‘Aesthetic value’ were higher, most of the wetlands evaluated as 2, 3 grade. Result of SOM analysis, ‘vegetation diversity and wild animals habitat’ is negatively related to the ‘Fish and herptile habitat’, because fishs were not prefer habitat excessively occupied by plant. However, high vegetation diversity can be support high score of ‘Aesthetic’ in wetland. Also, ‘Erosion control’ and ‘Flood storage and control’ were closely related, wetlands with high score of ‘Erosion control’ have high score of ‘Flood storage and control’. When applied RAM in domestic wetland, six out of 6 evaluation index induced biased results, the index of RAM need a little change as some new or modify evaluation index. Therefore, we consider to need adjustable, subdivide, and actualization of some evaluation index for application of RAM in domestic wetlands. Consequently, wetland assessment and class using RAM can be utilized as important indicate for conservation and management of wetland, and contributed greatly to maintain biodiversity include to endangered species by preserving remaining wetland.
        4,200원
        39.
        2017.04 구독 인증기관 무료, 개인회원 유료
        In the current administration, the government's main policies for youth employment and job creation are recognized by the Ministry of National Defense as a special environmental group. In particular, we believe that the self-help efforts of the advanced armed forces of the military, which are being pursued by the military, will fully demonstrate synergies with the current government policies. For this purpose, this study focuses on the people who are the targets of the youth employment, and suggests ways for them to have better jobs and values after the whole world. In accordance with the policy trends of job creation and job creation, we plan to propose a plan to link the national technical qualifications of the Korea Human Resources Development Service with the various projects currently underway for an average of 250,000 human resources development methods of 250,000 soldiers each year. This study suggests the link between IP (criticality performance) analysis and the Boston Consulting Group 's matrix (BCG Matrix) on the relevance of military human resource operations and qualifications. The results will be presented in conjunction with the military-oriented development projects of advanced countries currently under military control.
        4,000원
        40.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        MTO (Make to Order) is a manufacturing process in which manufacturing starts only after a customer’s order is received. Manufacturing after receiving customer’s orders means to start a pull-type supply chain operation because manufacturing is performed when demand is confirmed, i.e. being pulled by demand (The opposite business model is to manufacture products for stock MTS (Make to Stock), which is push-type production). There are also BTO (Build to Order) and ATO (Assemble To Order) in which assembly starts according to demand. Lean manufacturing by MTO is very efficient system. Nevertheless, the process industry, generally, which has a high fixed cost burden due to large-scale investment is suitable for mass production of small pieces or ‘mass customization’ defined recently. The process industry produces large quantities at one time because of the lack of manufacturing flexibility due to long time for model change or job change, and high loss during line-down (shutdown). As a result, it has a lot of inventory and costs are increased. In order to reduce the cost due to the characteristics of the process industry, which has a high fixed cost per hour, it operates a stock production system in which it is made and sold regardless of the order of the customer. Therefore, in a business environment where the external environment changes greatly, the inventory is not sold and it becomes obsolete. As a result, the company’s costs increase, profits fall, and it make more difficult to survive in the competition.Based on the customer’s order, we have built a new method for order system to meet the characteristics of the process industry by producing it as a high-profitable model. The design elements are designed by deriving the functions to satisfy the Y by collecting the internal and external VOC (voice of customer), and the design elements are verified through the conversion function. And the Y is satisfied through the pilot test verified and supplemented. By operating this make to order system, we have reduced bad inventories, lowered costs, and improved lead time in terms of delivery competitiveness. Make to order system in the process industry is effective for the display glass industry, for example, B and C groups which are non-flagship models, have confirmed that the line is down when there is no order, and A group which is flagship model, have confirmed stock production when there is no order.
        4,200원
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