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        검색결과 4,924

        821.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The current practice in car headlight visibility performance evaluation is based on the luminous intensity and illuminance of headlight. Such practice can be inappropriate from a visibility point of view where visibility indicates abilities to perceive an object ahead on the road. This study aimed at evaluating the appropriateness of current headlight evaluation methodMETHODS: This study measured the luminance of object and road surface at unlit roadways. The variables were measured by vehicle type and by headlight lamp type. Based on the measurements, the distance where drivers can perceive an object ahead was calculated and then compared against such distance obtained by conventional visibility performance evaluation.RESULTS: The evaluation method based on illuminance of headlight is not appropriate when viewed from the visibility concept that is based on object-perceivable distance. Further, the results indicated a shorter object-perceiving distance even when road surface luminance is higher, thereby suggesting that illuminance of headlight and luminance of road surface are not the representative indices of nighttime visibility.CONCLUSIONS : Considering that this study utilized limited vehicle types and that road surface (background) luminance can vary depending on the characteristics of the given road surface, it would likely go too far to argue that this study’s visibility performance evaluation results can get generalized to other conditions. Regardless, there is little doubt that the current performance evaluation criterion which is based on illuminance, is unreasonable. There should be future endeavors on the current subject which will need to explore study conditions further, under which more experiments should be conducted and effective methodologies developed for evaluating automotive headlight visibility performance. Needs are recognized particularly in the development of headlight visibility performance evaluation methodology which will take into account road surface (background) luminance and luminance contrast from various perspectives as the former indicates the driver’s perception of the front road alignment and the latter being indicative of object perception performance.
        4,000원
        822.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The mortality rate in industrial accidents in South Korea was 11 per 100,000 workers in 2015. It’s five times higher than the OECD average. Economic losses due to industrial accidents continue to grow, reaching 19 trillion won much more than natural disaster losses equivalent to 1.1 trillion won. It requires fundamental changes according to industrial safety management. In this study, We classified the risk of accidents in industrial complex of Ulju-gun using spatial analytics and data mining. We collected 119 data on accident data, factory characteristics data, company information such as sales amount, capital stock, building information, weather information, official land price, etc. Through the pre-processing and data convergence process, the analysis dataset was constructed. Then we conducted geographically weighted regression with spatial factors affecting fire incidents and calculated the risk of fire accidents with analytical model for combining Boosting and CART (Classification and Regression Tree). We drew the main factors that affect the fire accident. The drawn main factors are deterioration of buildings, capital stock, employee number, officially assessed land price and height of building. Finally the predicted accident rates were divided into four class (risk category-alert, hazard, caution, and attention) with Jenks Natural Breaks Classification. It is divided by seeking to minimize each class’s average deviation from the class mean, while maximizing each class’s deviation from the means of the other groups. As the analysis results were also visualized on maps, the danger zone can be intuitively checked. It is judged to be available in different policy decisions for different types, such as those used by different types of risk ratings.
        4,000원
        823.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate the optimum conditions of dispersion and strength to maximize the mechanical properties of woody cellulose nano–crystal (CNC). As a dispersing method, ultrasonic dispersing machine and magnetic stirrer were used as the mechanical dispersion method. The mixing ratio of cellulose nano-crystals (CNCs) was 0.2% and the dispersion time was 10 minutes. Steam curing was carried out for 6, 24 and 48 hours. Based on the experimental results, we will propose source technology regarding CNC for construction materials.
        4,000원
        824.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study is to compare noise reduction quantities between before/after two-layer low noise pavement implementation using equivalent noise level analysis and to analyze the noise reduction effects of the two layer low noise pavement with a statistical method such as the Anderson-Darling Test.METHODS: In order to compare and to analyze noise reduction effects between before/after two-layer low noise pavement implementation, data acquisition as noise levels on a roadside and an apartment rooftop was conducted in the study area. The equivalent noise level was estimated in order to compare noise reduction quantities and the Anderson-Darling Test was carried out for estimating noise reduction effects of the two-layer low noise pavement.RESULTS: The equivalent noise levels of before/after two-layer low noise pavement implementation for the roadside during the daytime are 65.355 dB and 63.520 dB and during the nighttime are 62.463 dB and 59.088 dB. The equivalent noise levels for the apartment rooftop during daytime are 57.301 dB and 59.088 dB and during the nighttime are 54.616 dB and 52.464 dB. Also two-layer low noise pavement decreased the noise reduction effects estimated with the statistical method as the Anderson-Darling test for the roadside during the daytime by around 66.68% and decreased noise reduction effects on the roadside during the nighttime by 0.70%. Moreover it reduced noise reduction effects in the apartment rooftop during the daytime and nighttime by 0% and 96.32%, respectively.CONCLUSIONS : Based on the result of this study, two-layer low noise pavement can positively affect noise reduction during both the daytime and nighttime according to the results of estimating the equivalent noise levels and the Anderson-Darling test.
        4,200원
        825.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to gather precise information on the real fabric color and texture, and purchasing intention of mobile shoppers buying clothes. Eighty volunteers participated in the sensory test on three smartphones with four colors and two fabricssmooth taffeta and hairy doeskin. This study carried out the posteriori test using the one-way ANOVA and Duncan test by SPSS21.0. In the analysis’ results of color preference, there were no differences among the four colors of taffeta between the smartphones, but different preferences between the red and yellow doeskin exist. In the case of the Samsung phone, which has an immense color distortion, the red fabric has a low color preference. In contrast, on the Apple phone yellow fabric had the highest preference because of its brightness. The Apple phone also has the highest purchasing intention of yellow colored taffeta, which is similar to the color preference results, although the real fabric has the opposite result. For doeskin, the real red and blue colored fabric has the highest purchasing intention. The Samsung phone has the biggest color mismatch with the real fabric. It also has the lowest purchasing intention of red taffeta fabric, while the LG phone has the lowest purchasing intention of blue fabric. Using the paired comparison method of the similarity between ‘real’ fabrics and the mobile version of fabric colors has a low similarity on all four colors of taffeta and doeskin fabrics. Therefore it can be concluded that phones do not represent the ‘real’ fabric color.
        4,300원
        826.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        According to the nuclear safety act, the enforcement regulations and the notification of the atomic energy commission, a preliminary decommissioning plan must be submitted at all domestic nuclear facilities. In accordance with this preliminary decommissioning plan, it is required to prepare eleven items from the outline of the decommissioning plan of the nuclear facility to the fire protection. Currently, the nuclear fuel cycle facility operated by the Korea Atomic Energy Research Institute (KAERI) consists of a radioactive waste form test facility (RWFTF), a post irradiation examination facility (PIEF), a radioactive waste treatment facility (RWTF), and a radioactive waste storage facility (RWSF). The decommissioning strategies, decommissioning methods and dismantling activities of these nuclear facilities are described in this paper. The scope of decommissioning, the dismantling method, the final conditions of the site, the management of radioactive waste, and the cost of decommissioning are established in the decommissioning strategy. The decommissioning schedule, work order, basic principle and technical feasibility are determined at the method of decommissioning. The disinfection techniques and activity plans for facilities and sites contaminated with radioactive materials are described at the dismantling activity. Therefore, this paper describes the concept of decommissioning of the nuclear fuel cycle facilities and prepares a preliminary decommissioning plan to be prepared afterwards.
        4,200원
        827.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the surface passivation process for InP-based quantum dots (QDs) is investigated. Surface coating is performed with poly(methylmethacrylate) (PMMA) and thioglycolic acid. The quantum yield (QY) of a PMMA-coated sample slightly increases by approximately 1.3% relative to that of the as-synthesized InP/ZnS QDs. The QYs of the uncoated and PMMA-coated samples drastically decrease after 16 days because of the high defect state density of the InP-based QDs. PMMA does not have a significant effect on the defect passivation. Thioglycolic acid is investigated in this study for the effective surface passivation of InP-based QDs. Surface passivation with thioglycolic acid is more effective than that with the PMMA coating, and the QY increases from 1.7% to 11.3%. ZnS formed on the surface of the InP QDs and S in thioglycolic acid show strong bonding property. Additionally, the QY is further increased up to 21.0% by the photochemical reaction. Electron–hole pairs are formed by light irradiation and lead to strong bonding between the inorganic and thioglycolic acid sulfur. The surface of the InP core QDs, which does not emit light, is passivated by the irradiated light and emits green light after the photochemical reaction.
        4,000원
        828.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the current status of odor and to examine the application method of the odor emission standard in a restaurant environment. The complex odor dilution concentrations (“times”) and odor compounds were measured in 8 restaurants. The highest complex odor dilution times were 966 in outlets and 97 in site boundaries of C restaurants. The average complex odor dilution times were 632 in outlets and 29 in site boundaries, which exceeded the allowable odor discharge standard of residential areas. Eighteen of the 22 specified offensive odor substances were detected. Aldehyde-type substances showed high concentrations, and the highest concentration of ethanol was detected in addition to the designated odorous substances. Dichloromethane, benzene, and phenol, which are harmful air pollutants, were also detected. The odorant concentrations of restaurants were found to exceed the odor standard threshold in A, B, and F restaurants. Upon review of the Japanese-style odor index respective to restaurant odor, it is difficult to apply an equivalent emission allowance standard as the permissible emission standard of the workplace. It is necessary to regulate emission standards by different emission standards. In the future, it will be necessary to determine how to measure the odor index and how to apply the odor emission standard to everyday facilities, such as restaurants, grocery stores, etc.
        5,200원
        831.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The coupled shear wall system with coupling beams is an efficient structural system for high-rise buildings because it can provide excellent ductility and energy dissipation to the buildings. The objective of this study is to simulate the hysteretic behavior of diagonally reinforced concrete coupling beams including pinching and cyclic deteriorations in strength and stiffness using a numerical model. For this purpose, coupling beams are modeled with an elastic beam element and plastic spring element placed at the beam ends. Parameters for the analytical model was calibrated based on the test results of 6 specimens for diagonally reinforced concrete coupling beams. The analytical model with calibrated model parameters is verified by comparing the hysteretic curves obtained from analysis and experimental tests.
        4,000원
        832.
        2017.11 구독 인증기관·개인회원 무료
        최근 우리나라의 고령자 인구 비율이 증가함에 따라 고령자의 삶의 질 향상에 대한 요구가 증가되고 있다. 이에 고령자를 위한 연화식 개발을 위해 삼치의 연도 개선에 적합한 열처리 공정 방법에 대한 연구를 수행하였다. 본 연구에서는 열처리 공정 방법(conventional steam, superheated steam (chamber temp.: 100, 200°C )의 가열 시간(1-30 min)에 따른 삼치(3×3×1cm3)의 경도 변화, 조리 감량, 수분함량 변화를 분석하였다. Conventional steam은 100°C 수증기를 이용한 열처리 방법으로 가열 시간 (1-30 min) 증가에 따른 삼치의 경도는 일정하게 유지되었다. Superheated steam 100°C에서는 처리시간이 증가함에 따라 conventional steam과 유사하게 경도가 유지되었고, 200°C에서는 가열 시간 5min 까지는 conventional steam과 경도에서 유의차가 없었다. 하지만 조리시간 10 min 이상에서는 조리시간 증가에 따라 경도가 증가하였다. 조리 감량은 1, 5, 10, 20, 30 min 처리시간이 증가함에 따라 conventional steam의 경우 각각 8.0, 16.9, 20.6, 26.6 25.2 %로 나타났고, superheated steam 100°C에 의해서는 각각 8.6, 17.0, 19.1, 22.1, 24.9 %로 200°C에서는 각각 11.8, 22.1, 37.4, 60.8, 66.0 %로 나타났다. 열처리 공정 방법에 따른 수분함량의 변화는 처리시간이 증가함에 따라 감소하였고, 감소 속도에서 conventional steam과 superheated steam 100°C 처리는 유사하게 측정되었고, superheated steam 200°C 처리는 빠르게 감소하는 것으로 측정되었다. 즉, 100°C에서는 conventional steam 또는 superheated steam 방법에 따른 경도 차이가 없었고, 처리시간이 증가함에 따른 경도 변화도 미미하게 나타났다. 반면 200°C superheated steam 가열 공정 시 10 min 이상 처리시간은 경도와 조리 감량의 급격한 증가와 수분함량의 감소가 유도되었다.
        833.
        2017.11 구독 인증기관·개인회원 무료
        마카(Lepidium meyenii)는 안데스산맥 해발 4.000미터 이상의 고지에서 자생하는 페루의 인삼으로 알려져 있다. 마카는 탄수화물 60~75%, 단백질 10~14%, 지질 2%, 섬유질 8.5%, 다량의 필수아미노산, 철분 및 칼슘 등을 함유하는 영양식품으로 알려지면서 2010년대 이후 건강식품으로 주목을 받고 있다. 마카에는 리놀렌산, 팔미트산, 올레인산 같은 지방산, 식물성 스테롤 및 미네랄도 다량 함유하고 있으며, 지표성분인 마카엔(macaene)이나 마카마이드(macamide)와 같은 다른 식물에서 발견되지 않는 고유의 불포화지방산이 존재한다. 마카는 항암작용, 불임증 해소, 남성의 정자 수 증가, 월경 증후군 및 갱년기 증상완화 같은 효능 역시 보고되어 왔다. 본 연구에서는 추출용매의 특성을 이용하여 중국산 마카로부터 다양한 생리활성물질의 추출효율을 최적화하고자 하였다. 마카는 중국(윈난성)산으로 에스에스바이오팜㈜에서 제공받았으며, 추출용매는 식품에 사용가능한 주정, n-헥산, 물을 사용하였다. 생리활성물질은 Lowry 방법에 의한 단백질, Phenol-sulfuric 방법에 의한 총 당, DNS 방법에 의한 환원당, Aluminum nitrate colorimetry 방법에 의한 플라보노이드, Folin-Ciocalteu colorimetry 방법에 의한 페놀화합물, DPPH Radical Scavenge capacity를 이용한 항산화력, HPLC 방법에 의한 마카마이드 B(N-benzyl hexadecanamide)를 분석하였다. 마카추출액의 제조는 5시간의 추출시간과 마카와 추출용매의 비율(10%, w/v)을 기준으로 Soxhlet을 이용한 Reflux 방식과 40°C에서 교반하는 suspension방식을 적용하였다. Reflux 추출방법으로 추출된 전체 생리활성물질은 50% 및 100% 주정을 용매에서 27g%로 가장 높은 반면 지표성분인 마카마이드 B는 주정과 헥산이 1:1 혼합된 50% 헥산용매에서 85 mg%로 가장 높았다. 추출물의 항산화력은 1N HCl_주정을 이용한 추출물에서 1,050 mg%로 가장 높은 결과를 얻었다. 한편 단순 교반에 의한 Suspension 추출방법으로 1N HCl 주정을 이용한 경우 전체 생리활성물질은 64 g%로 Reflux 방식의 최대 추출효율 대비 2배 이상 추출효율이 향상되었다. Suspension 방법에 의한 추출물의 마카마이드 B는 50% 헥산용매에서 70 mg%, 100% 주정에서 61 mg%, 그리고 1N HCl 주정에서 59 m%로 유사한 수준이었다. 추출물의 항산화력 역시 1N HCl_주정을 이용한 Suspension 추출방법에서 974 mg%로 Reflux 방법의 추출효율과 유사하였다. Suspension방법으로 1N HCl 주정을 이용한 마카추출물은 100% 주정을 이용한 추출물 대비, 마카마이드 B, 플라보노이드, 항산화력은 유사한 수준인 반면 전체 생리활성물질의 추출효율은 4.5배, 페놀화합물, 총 당의 추출효율은 3배 이상 향상되었다. 따라서 마카로부터 생리활성물질의 대량생산은 1N HCl 주정을 이용하는 Suspension방법이 가장 효율적이었다.
        834.
        2017.11 구독 인증기관·개인회원 무료
        본 연구는 제주마와 더러브렛을 교잡한 제주산마의 사양 방법에 따른 등심근의 일반 성분과 지방산 조성를 조사하기 위해 수행되었다. 공시축으로 36개월령 이상 제주산마(더러브렛×제주마) 16두를 처리구별 8두씩(개별 사양 8두, 군집 사양 8두) 배치하였다. 농후사료 급여는 말 체중의 2.5%를 일일 4회 나눠서 3개월간 급여하였고, 건초(라이그라스)와 물은 무제한 급여한 후 도축하여 등심근을 분석에 공시하였다. 제주산마 등심근의 일반 성분 조사 결과, 개별 사양을 한 처리구가 군집 사양을 한 처리구보다 수분함량은 낮고(p<0.05) 지방함량이 높았다(p<0.05). 지방산 조성 분석 결과, Palmitic acid와 포화지방산은 개별 사양 처리구가 집단 사양 결과보다 유의적으로 높게 나타났으나(p<0.05) 불포화지방산은 군집 사양 처리구에서 유의적으로 높게 나타났다(p<0.05). 이상의 결과를 종합해보면 말의 사양 방법은 말고기의 일반 성분, 지방산 조성 등에 유의적인 영향을 미치기 때문에 비육마의 경우 목적에 맞는 사양 방법 선택이 필요한 것으로 생각된다.
        835.
        2017.11 구독 인증기관·개인회원 무료
        목적: 정시안과 안경 및 콘택트렌즈 착용 근시안의 조절반응량을 비교하고, 근시안에서는 굴절 이상도와 조절반응량의 상관성을 확인하고자 하였다. 방법: 안질환 및 전신질환이 없고 굴절교정수술을 하지 않은 성인 (19~25세) 중 암실 (scotopic) 조명상태에서 Pupilmeter (VIP™-200, NEUROPTICS, USA)를 이용하여 동공크기를 측정한 뒤, 그 크기가 평균 동공크기 7.5±0.8 mm 이내(6.7 ~ 8.3 mm)의 인원을 선별하여 대상자로 정시안 16명, 근시안 25명 총 41명이 참여하였다. 굴절검사는 포롭터를 이용한 자각식 굴절검사 시행하였다. 근시안의 경우 안경렌즈와 콘택트렌즈로 완전교정한 후 양안개방형 ARK(autorefractokeratometer, NVISION-K 5001, SHIN-NIPPON, JP)를 이용하여 원/근거리(5 m/33 cm)를 주시하게 한 후 조절반응량을 측정하였다. 통계분석은 MedCalc Version 17.9.7 (MedCalc, Belgium)을 이용하였고, 안경렌즈 교정군과 콘택트렌즈 교정군의 조절반응량은 독립표본 t 검정(independent t-test)으로, 굴절이상도에 따른 조절반응량은 Pearson correlation test를 이용하여 상관성검정을 하였다. 모든 통계분석은 p값이 0.05 미만인 경우를 유의한 차이가 있는 것으로 해석하였다. 결과: 양안개방형 ARK로 측정한 조절반응량은 근시안이 정시안에 비해서 작았고, 안경렌즈 교정군과 콘택트렌즈 교정군의 조절반응량은 유의한 차이가 없었다(p=0.849). 양안개방형 ARK로 측정한 조절반응량과 근시도는 안경렌즈 착용군(r=0.4726, p=0.0197), 콘택트렌즈 착용군 (r=0.4745, p=0.0191)에서 모두 상관성이 있는 것으로 나타났다. 결론: 정시안이 근시안에 비해 조절반응량이 높았고, 근시도가 증가할수록 조절반응량은 작았다. 안경렌즈 교정군과 콘택트렌즈 교정군의 조절반응량은 유의한 차이가 없어 이에 대한 추가적인 연구가 필요할 것으로 생각된다.
        837.
        2017.11 구독 인증기관·개인회원 무료
        목적: 본 연구는 소프트 콘택트렌즈의 제조를 위해 상온중합과 열중합 방법을 사용하였으며 제조된 콘택트렌즈의 물성을 각각 비교, 분석하였다. 방법: HEMA(2-hydroxyethyl methacrylate)와 증류수 그리고 개시제 및 촉매제를 혼합하여 기본 조합으로 하였으며 1-vinylimidazole를 첨가제로 사용하여 상온중합 하였다. 또한 개시제인 AIBN(azobisisobutyronitrile), 가교제인 EGDMA(ethylene glycol dimethacrylate)를 사용하여 열중합 하였다. 제조된 하이드로젤 렌즈의 물리적 특성을 평가하기 위해 함수율, 굴절률, 분광 투과율, 인장강도 및 파단강도를 각각 측정하였다. 결과: 제조된 고분자의 물리적 특성을 측정한 결과, 상온중합과 열중합을 비교하였을 때 열중합이 상온중합에 비해 함수율이 낮게 나타났으며 자외선 영역에서 낮은 투과율을 보여 다소 차단되는 것으로 나타났다. 두 조합 모두 첨가제인 1-vinylimidazole 양이 증가함에 따라 함수율이 낮아지는 경향을 나타내었다. 또한 인장강도의 경우 0.1687에서 0.1215kgf/mm2로 다소 감소하는 경향을 나타내었다. 결론: 본 연구를 통해 상온중합으로 콘택트렌즈 제조한 결과, 열중합과 비슷한 경향을 나타내어 하이드로젤 렌즈의 중합방법으로 적절하다고 판단된다.