검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 5,861

        1001.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        해양사고 예방을 위해서는 사고의 원인과 결과에 대한 분석 및 진단뿐만 아니라, 사고의 발생 패턴과 변화 추이를 예측함으로 써 정량적 위험도를 제시할 필요성이 있다. 선박교통과 관련된 해양사고 예측은 선박의 충돌위험도 분석 및 항해 경로 탐색 등 선박교통 의 흐름에 관한 연구가 주로 수행되었으며, 해양사고의 발생 패턴에 대한 분석은 전통적인 통계 분석에 따라 제시되었다. 본 연구에서는 해양사고 통계 자료 중 선박교통관련 사고의 월별, 시간대별 발생 현황 데이터를 활용하여 해양사고 발생 예측 모델을 제시하고자 한다. 국내 해양사고 발생 현황 중 월별, 시간대별 데이터 집계가 가능한 1998년부터 2021년까지의 통계자료 중 선박교통 관련 데이터를 분류하 여 정형 시계열 데이터로 변환하였으며, 대표적인 인공지능 모델인 순환 신경망 기반 장단기 기억 신경망을 통하여 예측 모델을 구축하 였다. 검증데이터를 통하여 모델의 성능을 검증한 결과 RMSE는 초기 신경망 모델에서 월별 52.5471, 시간대별 126.5893으로 나타났으며, 관측값으로 신경망 모델을 업데이트한 결과 RMSE는 월별 31.3680, 시간대별 36.3967로 개선되었다. 본 연구에서 제안한 신경망 모델을 기 반으로 다양한 해양사고의 특징 데이터를 학습하여 해양사고 발생 패턴을 예측할 수 있을 것이다. 향후 해양사고 발생 위험의 정량적 제 시와 지역기반의 위험지도 개발 등에 관한 추가 연구가 필요하다.
        4,200원
        1002.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 어장환경평가가 수행된 어류가두리 양식장의 조사 결과 중 일부를 대상으로 저서동물지수(Benthic Health Index, BHI)를 이용하여 양식장의 건강도를 평가하였으며, 평가 결과로 산출된 각 등급의 양식장 환경 특성을 파악하였다. 평가대상 어류가두리 양식장은 동해, 서해, 남해에 위치한 43개 양식장으로, BHI 1등급은 8개 양식장, 2등급은 4개 양식장, 3등급은 12개 양식장, 4등급은 19개 양식장이 포함되었다. 1등급 어류가두리양식장은 사질 퇴적상, 양식강도가 낮은 양식장이 포함되었으며, 2등급 어류가두리양식장은 해수 유통이 원활한 해역에 위치한 양식장이 속하였다. 3, 4등급이 속한 어류가두리양식장은 높은 강도로 양식 활동이 진행되고 있는 대다수의 양식장이 포함되었다. 3등급과 4등급의 양식장은 총유기탄소는 큰 차이가 없었으나, 다모류 군집분석의 결과는 4등급의 양식장에서의 유 기물 농축이 더 높은 것으로 나타났다.
        4,200원
        1003.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Various optical devices are utilized to fire artillery in Korean Army. To transport and store the optical devices, some cases are made up for a set. The covers of cases are made of Glass Fiber Reinforced Plastic(GFRP) and resin. Because of materials of case, it has a disadvantage in productivity for manufacturing covers and assembling components. In this study, ABS resin is presented for alternative and verify possibility through FEM analysis. Comparing with GFRP, max stress-ratio of ABS is decreased 19.6% for bottom, 8.2% for side and 25.4% for edge. Also each strain is changed 17.3%, 180.3% and 17.7%. According to the research results, ABS resin is considered possible for alternative. And the number of components is decreased for around 73.8%.
        4,000원
        1004.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Due to environmental pollution, regulations on fossil fuels are required. There is a movement for the regulations by using LNG fueled propulsion ships. LNG is an eco-friendly fuel that does not emit NOx or SOx during combustion, but its boiling point is -163°C. Under that condition, the use of metal is restricted, and IMO defined applicable materials through IGC code. Among the metals, 9% nickel steel is one of excellent mechanical properties such as yield strength and tensile strength in cryogenic condition. Thus 9% nickel steel is widely used in cryogenic storage containers for ships. In addition, laser welding, which minimizes thermoelastic distortion by applying a concentrated heat source to a narrow area for a short period of time, is in the spotlight. So, this study is a basic research to predict and respond to thermal distortion during laser welding. Secondary version of the representative heat source model was derived through the author's previous research with STS304L, and the heat source model was derived by applying the heat source model to 9% nickel steel in this study. 9% nickel steel is a material that is in high demand and is widely used in the manufacture of cryogenic containers, so this study is expected to be able to respond immediately to the field.
        4,000원
        1005.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, to improve the optical quality of aspherical plastic lenses for mobile use, the optimal molding conditions that can minimize the phase difference are derived using injection molding simulation, design of experiments, and machine learning. First, factors affecting the phase difference were derived using the design of the experiment method, and a data set was created using the derived factors, followed by the machine learning process. After predicting the model trained using the generated training data as test data and verifying it with the performance evaluation index, the model with the best predictive performance was the random forest model. Therefore, to derive the optimal molding conditions, random forests were used to predict 10,000 random pieces of data. As a result of applying the derived optimal molding conditions to the injection molding simulation, the phase difference of the lens could be reduced by 8.2%.
        4,000원
        1006.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most of automobile steering parts are manufactured through the multi-stage cold forging process using round-bar drawn materials. The same process is applied to the ball stud parts of the outer ball joint, and various research activities are being carried out to reduce the extreme manufacturing cost in order to survive in the limitless competition. In this paper, we present a quantitative prediction method for the limiting life of the die as a method for cost reduction in the multi-stage cold forging process. The load on the die was minimized by distributing the forming load based on process optimization through finite element analysis. In addition, based on the quantitative prediction algorithm of the limiting life of the die, the application of the split die and the optimization of the phosphate treatment of the material surface are presented as a conclusion as a method to improve the limiting life of the die.
        4,000원
        1007.
        2022.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The lattice oxygen mechanism (LOM) is considered one of the promising approaches to overcome the sluggish oxygen evolution reaction (OER), bypassing -OOH* coordination with a high energetic barrier. Activated lattice oxygen can participate in the OER as a reactant and enables O*-O* coupling for direct O2 formation. However, such reaction kinetics inevitably include the generation of oxygen vacancies, which leads to structural degradation, and eventually shortens the lifetime of catalysts. Here, we demonstrate that Se incorporation significantly enhances OER performance and the stability of NiFe (oxy)hydroxide (NiFe) which follows the LOM pathway. In Se introduced NiFe (NiFeSe), Se forms not only metal-Se bonding but also Se-oxygen bonding by replacing oxygen sites and metal sites, respectively. As a result, transition metals show reduced valence states while oxygen shows less reduced valence states (O-/O2 2-) which is a clear evidence of lattice oxygen activation. By virtue of its electronic structure modulation, NiFeSe shows enhanced OER activity and long-term stability with robust active lattice oxygen compared to NiFe.
        4,000원
        1008.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study was aimed to investigate the operational meal costs by kindergarten size in Seoul and to analyze recognition for optimal meal prices. A survey (31.6% recovery rate) was conducted on all kindergartens (779 kindergartens) in Seoul on April 2021 using descriptive analysis, t-test, and dispersion method. A price sensitivity measurement (psm) method was used to determine optimal meal prices. Result showed an average food cost for kindergartens of 2,647 won, an average labor cost of 605 won, an average operating cost of 146 won, and the total meal cost of 3,506 won. Total meal cost decreased with increasing kindergarten size (p<0.001). On the other hand, kindergartens with more students decreased the ratio of food cost to total meal cost, and operating cost and labor costs (p<0.001) increased. The optimal price of kindergarten operators' meal cost (OPP) was KRW 3,673. Furthermore, the analysis showed the sensitivity of operators' meal costs to kindergarten size was insignificant.
        4,000원
        1009.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As cholesterol intake increases, the prevalence of hypercholesterolemia is also increasing. With increasing food selection considering health, consumption of functional foods that can help health is also expected to increase. Ginger is rich in minerals (such as potassium and magnesium) and antioxidants. Antioxidants have been shown to be effective in lowering blood cholesterol levels. Therefore, we would like to produce madeleines helpful for hypercholesterolemia by adding ginger syrup to madeleines recently consumed as desserts. In this study, the quality and characteristics were analyzed after making madeleine by adding ginger syrup at 0%, 5%, 10%, 15%, and 20%. Baking loss was significantly reduced as the addition amount increased (p<0.001). The pH value decreased as the addition amount increased except for the 5% added group (p<0.001). The b value of the chromaticity showed a significant increase from the 5% addition group (p<0.001). Regarding textures, hardness (p=0.006), gumminess (p=0.001), and chewiness (p=0.001) all decreased as the addition amount increased. Regarding antioxidant activity, polyphenol, DPPH, and ABTS values were significantly increased as addition amount increased (p<0.001). Consequently, Madeleine using ginger syrup rich in antioxidants is expected to help health.
        4,000원
        1010.
        2022.08 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        신체적, 정신적 건강에 대한 관심이 높아지면서 몸, 마음, 정신의 통합을 목표로 하는 요 가가 생활스포츠의 하나로 자리매김하였다. 최근에는 도구 활용 요가가 신체균형개선, 자세 교정, 통증 완화 등 재활목적으로 활용되고 있다. 도구 활용 요가는 도구를 활용하여 안전 하고 효과적으로 근육을 이완시키거나 강화시켜 신체의 기능을 회복시키는 것을 돕는다. 도구를 활용하면 관절 가동범위를 무리하게 넘어서지 않고, 골격의 위치를 바르게 하며, 정 확하고 안정된 자세를 유지시켜, 자세교정 및 통증완화에 도움을 준다. 사용되는 도구는 볼 스터, 의자, 벨트, 담요, 블록, 라운드 블록, 프레임, 로프 등이다. 본 연구는 현대인들의 근 골격계 질환중 대표적인 거북목 증후군의 특징을 이해하고, 도구 활용 요가를 통해 거북목 증후군을 개선할 수 있는 맞춤형 도구 활용 요가 프로그램의 구성과 원리를 제안하였다.국 문 요약문(10줄 내외) 본 연구의 요약은 연구의 목적과 방법, 결과, 논의와 결론을 정리하며 주제와 개요를 명확하게 파악할 수 있도록 적는다.
        5,100원
        1011.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 산림자원으로 활용 가능한 활엽수림(혼효림 포함)의 상층 교목성 수종을 대상으로 유사한 수종구성을 갖는 산림 유형 분류를 통해 활엽수림의 효율적 산림관리 기반 구축을 위해 실시하였다. 제7차 국가산림자원조사 고정표본점(3,994지점) 중 2,291지점의 임분 현황 자료를 기반으로 클러스터분석, 지표종분석, 다중판별분석 등 다양한 다변량 통계분석 기법을 이용하여 산림 유형을 분류하였다. 활엽수림의 산림 유형은 신갈나무-피나무림, 신갈나무-당단풍나무림, 신갈나무-물푸레나무림, 신갈나무-굴참나무림, 신갈나무-소나무림, 졸참나무-굴참나무림, 소나무-신갈나 무림, 소나무-굴참나무림, 밤나무-아까시나무림, 상수리나무-소나무림 등 10개로 구분되었다. 신갈나무와 기타 활엽수림, 신갈나무가 우점하는 참나무 림, 주요 참나무류 수종과 소나무의 혼효림 형태로 구성된 것으로 파악되었다. 조사된 102종의 수종 중 점유비율이 높은 신갈나무, 굴참나무 및 소나무가 산림유형 분류에 중요한 역할을 한 것으로 나타났다.
        4,000원
        1012.
        2022.08 구독 인증기관 무료, 개인회원 유료
        This study was conducted to understand the current status of regional health inequalities and nurse supply and demand policies, and to suggest ways to supply nurses to regions where nurses are scarce. Secondary data such as academic papers, government announcements, and related laws were analyzed, and the results were reviewed from various perspectives to derive policy proposals. Health professions were distributed around large cities including Seoul, and those regions had relatively high health levels. However, the number of hospital beds increased steadily, mainly in the non-metropolitan area. This seems to be one of the reasons why there is always a shortage of nurses in the local medical field despite the supply of nurses, and it can be a factor that aggravates regional inequalities. In order to solve the chronic shortage of nurses, supply-oriented policies such as increasing the admission quota and utilizing inactive nurses, and demand-oriented policies such as regulations on the nurse staffing level and improvement of the incentive scheme for quality evaluation of hospital service have been implemented. In the past, the focus was simply on the quantitative expansion of nurses, but recently, policies that emphasize the qualitative aspect of nursing are being promoted. However, the policy for the distribution aspect of nurses is still somewhat incomplete. Therefore, to solve this problem, strengthening the nurse staffing level in medical institutions, promoting nursing policies led by local governments, developing standard wage guidelines, and training nurses as public health personnel were proposed.
        4,500원
        1013.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to understand the concept of zero-waste design and to apply Sophia Vyzoviti’s folding techniques to develop a zero-waste fashion design method that contributes to sustainable fashion design. In this study, we explore the method and characteristics of zero-waste fashion design based on the concept of folding described in Sophia Vyzoviti’s book on folding techniques. Using the autonomy of Sophia Vyzoviti’s folding technique, four changeable folding fashion designs were developed and produced, demonstrating zero-waste fashion design. The results were as follows. First, the development of fashion designs using Sophia Vyzoviti’s folding techniques enabled the development and production of free and creative zero-waste fashion designs that were three-dimensional, continuous, fluid, and full of potential. Second, the production of zero-waste patterns was further developed into a transformable fashion design that can be used with geometric patterns. These folding techniques produced a fashion design method that could transform one piece of clothing, demonstration the potential for maintenance of creativity using a zero-waste design based on these folding techniques. Third, the double-faced fabric, Neoprene, was chosen as an appropriate material as it emphasizes the depth of folding with application of two colors and its cotton/polyester blend that is suitable for folding.
        4,900원
        1014.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study was to investigate directions for future smart city transportation policies and service development by evaluating road service satisfaction levels and predicting future service demand. METHODS : A nationwide survey was conducted in Korea to develop a transportation service evaluation system based on the functions and objects of transportation. The satisfaction level of road service was evaluated using an analytic hierarchy process (AHP), promising service sectors were identified using the revised importance-performance analysis (IPA) technique, and detailed service demands by sector were suggested. RESULTS : The most valuable service value felt by the people was "safety" (weight 0.4), and the overall satisfaction level was 68.9 points, slightly exceeding "normal." As a result of analyzing the promising service sectors by dividing them into urban and rural areas, "handicapped, elderly, and pedestrians" were important in both areas, and "road facility maintenance" was classified as an additional promising sector for rural areas. CONCLUSIONS : People demand that future smart city transportation policies and services should be "people" and "safety" centered. In addition, it is necessary to pay attention not only to the development of new services but also to the improvement of problems with existing services and policies.
        4,000원
        1015.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : A methodology for estimating micro-emission factors using vehicle trajectory data collected from navigation and DTG devices and basic emission factors for each vehicle type of the MOtor Vehicle Emission Simulator (MOVES) is presented. The methodology can calculate micro-emissions based on only the traffic volume and average speed for each vehicle type. METHODS : Cluster analysis was performed by accumulating the trajectories of individual vehicles on a specific road section into speed groups in which vehicles drove with the same range of average speed. Then, the micro-emission factors were estimated for each speed group. RESULTS : Using the vehicle trajectory data revealed that the emissions calculated from micro-emission factors estimated by the proposed methodology were similar to the sum of the emissions calculated from the vehicle trajectories for each vehicle. CONCLUSIONS : The micro-emission factor database for each road type and vehicle type proposed in this study should be useful for estimating vehicle emissions on the road. The proposed method can calculate emissions in the same way as the macroscopic analysis method, using the traffic volume, average speed, and link length.
        4,000원
        1016.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study was to develop techniques for forecasting black ice using historical pavement temperature data collected by patrol cars and concurrent atmospheric data provided by the Korea Meteorological Administration. METHODS : To generate baseline data, the physical principle that ice forms when the pavement temperature is negative and lower than the dew-point temperature was exploited. To forecast frost-induced black ice, deep-learning algorithms were created using air, pavement, and dew point temperatures, as well as humidity, wind speed, and the z-value of the historical pavement temperature of the target segment. RESULTS : The suggested forecasting models were evaluated against baseline data generated by the above-mentioned physical principle using pavement temperature and atmospheric data gathered on a national highway in the vicinity of Young-dong in the Chungcheongbukdo province. The accuracies of the forecasting models for the bridge and roadway segments were 94% and 90%, respectively, indicating satisfactory results. CONCLUSIONS : Preventive anti-icing maintenance activities, such as applying anti-icing chemicals or activating road heating systems before roadways are covered with ice (frost), could be possible with the suggested methodologies. As a result, traffic safety on winter roads, especially at night, could be enhanced.
        4,000원
        1017.
        2022.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most of the drinking water dams managed by the local governments in Korea are earthfill dams, and these dams have almost no geotechnical property information necessary for seismic performance evaluation. Nevertheless, in the rough planning stage for improving seismic safety for these dams, it is necessary to classify their relative seismic hazard against earthquakes and conduct an additional ground investigation. The zero seismic failure probability curve is a curve suggested in this study in which the probability of failure due to an earthquake becomes ‘0’ regardless of the geotechnical properties of the earthfill dam. By examining the method and procedure for calculating failure probability due to an earthquake suggested in previous researches, the zero seismic failure probability curves for an earthquake in 1,000-year and 2,400-year return periods in Korea were presented in the form of a hyperbola on the plane of the dam height versus freeboard ratio (ratio of freeboard to dam height), respectively. The distribution characteristics of the dam height and the freeboard ratio of 81 Korean earthfill dams were presented. The two proposed zero seismic failure probability curves are shown on the plane of the dam height versus freeboard ratio, and the relative seismic hazard of 81 dams can be classified into three groups using these curves as boundaries. This study presented the method of classifying the relative seismic hazard and the classification result.
        4,000원
        1018.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 인공지능(AI) 기술이 급격하게 발전되고 있으며, 이를 활용한 산업이 점차 확대되고 있다. 또한 사회과학 연구분야에서 도 인공지능기술의 텍스트 마이닝을 활용한 분석연구가 활발하게 전개되고 있다. 해양수산부에서 소관하는 법률은 125여개로 해양환 경, 수산, 선박, 어촌, 항만 등 다양한 분야에서 제정되었다. 해양수산부 법률을 대상으로 한 연구가 활발히 진행되고 있으며, 양적으로 꾸준하게 증가하고 있다. 이 연구는 해양수산부 법률 관련 연구논문을 대상으로 텍스트 마이닝을 적용하여 국내 연구동향을 분석하였 다. 연구방법으로 첫째 텍스트 마이닝의 일종인 토픽 모델링을 수행하여 잠재된 토픽을 파악하였다. 둘째 특정 법률을 주제로 다룬 연 구논문의 동시출현 네트워크 분석을 수행하여 주요 주제를 도출하였다. 마지막으로 저자 네트워크 분석을 수행하여 저자 간 사회 연결 망을 탐색하였다. 분석결과 시기에 따라 핵심 토픽의 변화를 확인하였으며, 선박안전법, 해양환경관리법 등 법률별 주요 주제를 탐색하 였다. 또한 저자 네트워크 분석하여 핵심 연구자를 도출하고, 저자 간 공동연구 성향을 파악하였다. 이를 통해 해양수산부 법률 관련 연구주제의 변화를 탐색하였으며, 향후 연구주제의 다양화와 해양수산 분야 연구의 양적 증가와 질적 성장을 기대한다.
        5,200원
        1019.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 군산시 옥서면, 산북동, 비응도와 야미도, 신시도, 선유도 일대를 중심으로 야외지질학습을 위한 적절한 지질명소를 탐색하고 교육적 활용 방안을 논의하였다. 이를 위하여 2015 개정 교육과정의 지질 학습요소를 분 석하고 연구 지역에 관한 선행 연구를 바탕으로 현장 답사를 통해 7곳의 지질명소를 선정하였다. 이 일대는 중생대 쥐 라기부터 백악기 무렵 한반도 화성 활동의 결과로 형성된 화성암류와 백악기 퇴적암류, 공룡 발자국 및 식물 화석, 연 흔, 습곡 등 한반도 중생대 지질을 이해하는데 교육적 가치를 지니고 있다. 지질명소의 학습요소를 교육과정과 비교한 결과, 초등학교 고학년 수준에서 고등학교 수준의 학습요소를 내포하고 있으며 특히 고등학교에서 다루어지는 학습요소 를 두루 갖추고 있었다. 이에 따라 군산시 일대 지질명소와 각 장소에서 이루어질 수 있는 교육 활동을 제안하였다.
        4,900원
        1020.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydro-forming technology is a technology that will replace the existing press-forming technology and is used in various industry range from automotive parts to electronic products. The advantage of this technology is that it has dramatically changed the existing processing method, and it can be said that the process reduction due to the reduction of parts, cost reduction, and high precision are mentioned. In this study, it is intended to present a design process using computer simulation by changing the sub-frame for automotive parts produced with the existing press forming technology to the hide-forming method. To this end, it is intended to use it as part design data by comparatively analyzing the cross-sectional shape and thickness reduction, which are the major factors necessary to determine the successful development of the developed parts.
        4,000원