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        검색결과 79

        21.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 가스추진 174K급 LNG 운반선의 가스 압축기실에서 발생하는 가스누출 모사를 통해 가스탐지기의 최적 위치를 분석 하였으며, 새로 개정된 IGC 코드에 명시된 안전규정을 만족하는 합리적인 방법도 함께 제안하였다. 가스압축기실에서의 LNG 가스누출 수치해석을 위해, 실제 ME-GI 엔진이 장착된 174K급 LNG 운반선의 압축기실 형상과 장비, 배관의 배치와 같은 치수로 3D 설계되었다. 가 스누설에 대한 시나리오는 305 bar의 높은 압력과 1 bar의 낮은 압력을 적용하여 진행하였다. 고압용 핀홀의 크기는 4.5, 5.0, 5.6 mm이고 저압용은 100, 140 mm이다. 해석 결과, 5.6 mm 핀홀(고압)과 100, 140 mm 핀홀(저압) 상태의 누출에 대한 환기평가에서 가연성 가스농도는 심 각한 위험이 없음을 확인하였다. 그러나 개정된 IGC 코드에 따라 설치된 압축기실의 가스 감지 센서의 실제 위치는 다른 지점으로 이동 해야 하고, 측정 지점이 현 규정에서 요구하는 것보다 더 추가되어야 함을 확인하였다.
        4,000원
        22.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of supplementary feeding levels on livestck and forage productivity and grazing intensity in Elk stags (Cervus canadensis). A fifteen 2-year-old Elk stags about 195 kg were randomly assigned to one of three dietary treatments (five animals per treatment). The dietary treatments consisted of a feeding concentrate of 1.0% of body weight (T1), 1.5% of body weight (T2) and 2.0% of body weight. Total dry matter intake (TDMI) was increased with increased with an increasing supplementary feeding levels. Average daily gain (ADG) were significantly increased with an increasing supplementary feeding levels (p<0.05) and reached a maximum on July and was lower in spring than autumn. The velvet antler production was no differences among treatment groups. Forage productivity of pasture and crude protein content were highest on May and decreased thereafter, however, crude fiber content was the reversed. The grazing intensity of Elk stags was increased in spring (38 to 59 head per ha) than summer and autumn (13 to 32 head per ha). The average grazing intensity of Elk stags ranged from 21 to 34 head per ha, which is affected by supplementary feeding levels. This result suggests that feeding supplementary diet at 1.5 % of body weight was needed to maintain the stable wight gain in antler growing periods and control the proper grazing intensity of Elk deer stags.
        4,000원
        26.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 저성장-인구감소 시대를 맞아 발생한 구릉지의 유휴공간을 생태적으로 복원하여 미래의 불확실성에 대비하는 공간으로 창출하기 위한 계획 방법에 관한 것이다. 군산시 해신동 일대를 대상으로 하였으며, 계획을 위해 ‘안전한 기반’, ‘생물서식 기반’, ‘지속가능한 유지관리 기반’을 조성하는 전략을 구상하였다. 먼저, 불안정해진 경사지의 지반을 복원하여 안전한 기반을 마련하고자 하였다. 둘째, 복원 목표종이 서식할 수 있는 생물서식 기반을 조성하고자 하였다. 셋째, 지속가능한 공간으로 조성하기 위해서 기후변화에 대응할 수 있는 LID 계획, 기존 자원을 재활용한 시설물 계획, 그리고 커뮤니티를 활용한 거버넌스 창출 등을 계획하였다. 본 계획은 방치된 구릉지의 유휴공간을 어떻게 생태적으로 복원하는지, 어떻게 야생 동식물에게 새로운 서식환경을 제공하고 인간이 함께 공생하고 지켜나갈 수 있는지, 계단식 지형이 갖는 불리한 특성을 어떻게 문화적인 이점으로 활용하여 복원하는지 등에 대하여 이해할 수 있는 자료를 제시하였다.
        4,300원
        27.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        통합과 포용력이 사회의 주요한 이슈로 부각되면서, 사회적 약자인 노년층과 저소득 계층의 여가 활동을 충족시키는 도시계획시설에 대한 역할이 주목받고 있다. 본 연구는 노원구 △△영구임대주택 거주민을 대상으로 옥외활동 시설에 대한 이용 실태와 주요 공간 이용에 따른 사회적 관계망 형성 효과를 분석하였다. 분석은 빈도, t-분석 그리고 사회연결망 분석 방법을 활용하였다. 분석결과, 단지 내 공간 및 시설이용 빈도는 복지관(36.9%), 나팔공원(17.9%), 텃밭(10.2%)의 순으로 나타났으며, 1인이 교류하는 이웃의 수는 텃밭(13.44명), 나팔공원(6.47명), 복지관(5.13명) 이용자의 순으로 나타났다. 특히, 텃밭 이용자는 이웃 간 교류의 범위가 가장 넓게 나타났으며, 다양한 그룹을 통해 정보의 교류가 활발히 일어나고 있었다. 관계의 질적 수준 역시 일반적인 교류의 수준을 넘어 정보 교류 및 문제 발생 시 적극적으로 도움을 주고받는 상호 부조의 관계를 유지하는 것으로 확인되었다. 반면 산책, 휴식, 운동 등의 여가 활동이 이루어지는 나팔공원과 교육 활동이 제공되는 복지관의 경우 이용자들 간 교류의 범위가 좁고 집중화된 정도가 소수 그룹에 한정되었다. 본 연구는 영구임대주택에 거주하는 취약계층을 대상으로 주민들의 자발적인 교류와 지속적인 옥외활동을 촉진하는 공간 및 시설에 대한 사회적 기능을 밝혔다는데 의의가 있다.
        4,200원
        28.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        엘크 수사슴의 체중 성장곡선 및 일당증체량을 추정하기 위하여 국립축산과학원 가축유전자원센터에서 사육중인 엘크 수사슴 183두의 체중-일령 자료 1,509개에 대해 비선형 회귀식인 Gompertz와 Logistic 모형을 적용하였다. 추정된 엘크 수사슴 성장곡선 모수인 성숙체중(A), 성장비율(b)과 성숙률(k)은 Gompertz 모형의 경우 각각 335.5±1.415kg, 2.18±0.045와 0.0025±0.00005였고, Logistic 모형에서는 330.5±1.337kg, 5.46±0.209와 0.0355±0.00009였다. 적합도 검정을 위한 결정계수(R2)는 두 모형에서 큰 차이가 없어 두 모형 다 적합한 것으로 나타났다. 다만, 실제 측정값과 추정값에 대한 차이인 평균제곱근 오차 값이 엘크 암사슴에 비해 크게 나타났으며 따라서 엘크 수사슴의 낙각 및 번식기 체중 증감을 고려한 성장곡선 모형에 대한 추가적인 연구가 필요할 것으로 판단된다. 엘크 수사슴에서 Gompertz 모형으로 추정된 함수식은 f(t)=335.5Xe^-2.18e^-0.0025t였고, Logistic 모형의 경우 F(t)=330.5X(1+5.465e^-0.00355t)^-1였다. 각 모형에서 제1차 도함수로 유래된 일당증체량 곡선은 Gompertz 모형의 경우 F'(t)=0.0025Xf(t)X1n(335.5/f(t)), Logistic 모형의 경우f'(t)=0.0036Xf(t)X[1-f(t)/330.5]였다. 이 함수식을 통해 도출된 엘크 수사슴에서 최대 증체량을 나타내는 시기인 315~478.3일령, 123.4~165.3㎏ 도달 전후에는 보다 세심한 사양관리가 필요할 것으로 보인다. 본 연구에서 도출된 엘크 수사슴의 성장곡선 모수 추정값, 변곡점 및 변곡점 도달일령 등은 사슴산업 종사자들이 사양관리 및 육종계획을 수립하는 데에 도움이 될 수 있을 것으로 사료된다.
        4,000원
        29.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to predict the energy requirements for maintenance and growth of female Korean black goats during their growth and pregnancy phases. Fifty female goats (18.7±0.27 kg) in their growth phase with an average age of 5 months were stratified by weight and randomly assigned into 5 groups. They were fed 5 diets varying in metabolic energy (ME) [2.32 (G1), 2.49 (G2), 2.74 (G3), 2.99 (G4), and 3.24 (G5) Mcal/kg] until they were 9-month-old. After natural breeding, 50 female goats (30.7±0.59 kg) were stratified by weight and randomly assigned into 5 groups. They were fed 5 diets varying in ME [2.32 (P1), 2.43 (P2), 2.55 (P3), 2.66 (P4), and 2.78 (P5) Mcal/kg]. The average feed intake ranged between 1.5 and 2.0% of the body weight (BW), and there was no significant difference between the treatment groups with goats in growth or pregnancy phases. Average daily gain (ADG) in diet demand during the growth phase increased with an increasing ME density and ranged from 46 to 69 g/d (p<0.01). Feed conversion ratio (FCR) improved with the ME density during the growth phase (p<0.01). The intercept of the regression equation between ME intake and ADG indicated that energy requirement for maintenance of goats during growth and pregnancy phases was 103.53 kcal/BW0.75 and 102.7 kcal/BW0.75, respectively. These results may serve as a basis for the establishment of goat feeding standards in Korea. Further studies are required to assess the nutrient requirement of goats using various methods for improving accuracy.
        4,000원
        30.
        2019.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Three-dimensional(3D) printing is a process for producing complex-shaped 3D objects by repeatedly stacking thin layers according to digital information designed in 3D structures. 3D printing can be classified based on the method and material of additive manufacturing process. Among the various 3D printing methods, digital light processing is an additive manufacturing technique which can fabricate complex 3D structures with high accuracy. Recently, there have been many efforts to use ceramic material for an additive manufacturing process. Generally, ceramic material shows low processability due to its high hardness and strength. The introduction of additive manufacturing techniques into the fabrication of ceramics will improve the low processability and enable the fabrication of complex shapes and parts. In this study, we synthesize silica composite material that can be applied to digital light processing. The rheological and photopolymeric properties of the synthesized silica composite are investigated in detail. 3D objects are also successfully produced using the silica composite and digital light processing.
        4,000원
        31.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        황금배’에서 염화칼슘 침지 처리에 따른 유통 중 품질을 조사한 결과, 0.5% 염화칼슘 처리구가 20.5-21.3N으로 다소 높게 유지되었다. 과피색의 변화에 있어 적색도인 a*은 무처리구는 -2.62로 가장 높았고, 염화칼슘+ 초음파 처리구가 -3.03~-4.13으로 가장 낮아 과피의 녹색소실이 지연되었다. 유통환경에서 가장 많이 발생한 생리장해는 과육갈변으로 무처리구 과실에서 지수 28로 가장 높았고, 0.5% 농도에서는 침지 13, 초음파병행구 10으로 유의하게 낮았다. FSD 발생은 무처리구에서 지수 9로 칼슘처리구에 비해 발생이 높았고 과심갈변 발생은 처리간 유의한 차이를 볼 수 없었다. ‘원황’를 대상으로 리소포스파티딜에탄올아민(LPE)의 수확 후 처리 효과를 1-MCP 처리와 비교 조사한 결과, 과실 경도는 1-MCP 처리구는 유통과정 중 33N 이상으로 일정하게 유지되는 등 유통 중 경도저하가 낮았으나 유통 21일에 LPE 처리구에서 29.04N으로 다소 낮았다. 생리장해 발생에 있어 1-MCP 처리구는 유통 14일까지 유의하게 생리장해 발생지수가 낮아 효과적이었는데 유통 21일에 FSD 발생이 무처리구 및 LPE 처리구에 비해 2배 증가한 결과를 제외하고는 전반적으로 생리장해 발생이 유의하게 낮았다. 한편, LPE 처리구는 무처리구에 비해서는 생리장해 지수가 낮았으나 1-MCP에 비해서는 상대적으로 높은 결과를 보였다.
        4,000원
        34.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study was conducted to determine effects on forage productivity, feed value, grazing intensity and livestock productivity in growing Korean native female goat grazing in native pasture. Its with average initial body weight of 14.10±3.6kg and an average age of 4 months were used in this study. Dry matter content of native pasture was the highest at 33.48 ± 2.56% in June, and the content was significantly increased from spring to autumn (p<0.05). Crude protein was maintained between 11% and 12% on average. Nutrient content was maintained at a certain level in native pasture, but there were differences due to the different types of wild grasses produced in each season. The productivity of forage crops increased from June, but decreased after August and showed a characteristic of grassland where productivity decreased rapidly in spring and autumn. The average grazing intensity are 39 head/ha. Black goat average daily gain was 80.2g/d. The stable weight gain in grazing is that the nutrient requirement of the black goat was met by supplementing the concentrated feed during grazing. study, can be expected that the productivity of livestock can be increased through the proper feeding of supplementary feed and maintenance of grazing intensity
        4,000원
        35.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to estimate the growth curve parameters of body weight for female Elk. Weight and age data from 115 does raised at the Animal Genetic Resources Research Center in Korea were used in this study. The growth curve parameters were estimated from a nonlinear regression using Gompertz and Logistic models. Mature weight (A), growth ratio (b) and maturing rate (k) of female Elk were 214.1±2.17 kg, 2.12±0.0045 and 0.0043±0.00011, respectively, according to the Gompertz model. They were 208.3±2.17 kg, 5.56±0.234 and 0.0065±0.00017, respectively, according to the Logistic model. The goodness of fit determined by R2 was higher in the Gompertz model than that in the Logistic model. The growth curve functions obtained from the Gompertz and Logistic models in female Elk were f(t)=214.1×e-2.124×e-0.00484×t and f(t)=208.3×(1+5.561×e-0.00651×t)-1, respectively. The absolute growth rate functions from the Gompertz and Logistic models in female Elk were f'(t)=0.0043×f(t)×1n(214.1/f(t)) and f'(t)=0.0065×f(t)×[1-f(t)/208.3]respectively. The growth pattern of female Elk generated from this study can be useful in determining the most appropriate feeding plans and the best breeding strategies for deer.
        4,000원
        36.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The objective of this study is to develop a pavement rehabilitation decision tree considering current pavement condition by evaluating severity and distress types such as roughness, cracking and rutting. METHODS: To improve the proposed overall rehabilitation decision tree, current decision tree from Korea and decision trees from other countries were summarized and investigated. The problem when applying the current rehabilitation method obtained from the decision tree applied in Seoul was further analyzed. It was found that the current decision trees do not consider different distress characteristics such as crack type, road types and functions. Because of this, different distress values for IRI, crack rate and plastic deformation was added to the proposed decision tree to properly recommend appropriate pavement rehabilitation. Utilizing the 2017 Seoul pavement management system data and considering all factors as discussed, the proposed overall decision tree was revised and improved. RESULTS: In this study, the type of crack was included to the decision tree. Meanwhile current design thickness and special asphalt mixture were studied and improved to be applied on different pavement condition. In addition, the improved decision tree was incorporated with the Seoul asphalt overlay design program. In the case of Seoul's rehabilitation budget, rehabilitation budget can be optimized if a 25mm milling and overlay thickness is used. CONCLUSIONS: A practical and theoretical evaluation tool in pavement rehabilitation design was presented and proposed for Seoul City.
        4,200원
        37.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: In order to evaluate a crack resistance at cold joint, sealing tape was adopted to apply at cold joint instead of typical tack coat material(RSC-4). The sealing tape was made by hot sealing material. The crack resistance as function of environmental and traffic loading was measured with visual observation. METHODS : In this study, the crack resistance was evaluated as function of environmental and traffic loading. The freeze-thaw method was adopted for environmental loading of asphalt pavement. condition. The damage of cold joint under freeze-thaw action is initiated by ice expansion load and accelerated by the interfacial damage between new and old asphalt pavement. The traffic loading was applied with wheel tracking machine on the cold joint area of the asphalt pavement for 3 hours at 25℃. The evaluation of crack resistance was measured with visual observation. The freeze-thaw results shows that the sealing tape was significantly increased the crack resistance based on. RESULTS : To estimate the crack resistance at cold joint area due to the environmental loading, the Freeze-thaw test was conducted by exposing the product to freezing temperature(approximately -18℃) for 24 hours, and then allowing it to thaw at 60℃ for 24 hours. The tack coat material(RSC-4) was debonded after 21 cycles of the Freeze-thaw test. The first crack was observed after 14 freeze-thaw cycle with RSC-4 material. But, the sealing tape was not debonded after 24 cycle test. Also, the sealing tape shows the better performance of the crack resistance under the traffic loading with wheel track test. The crack was generated the under traffic loading with RSC-4(tack coating), however, the crack was not shown with sealing tape. It indicates that the sealing tape has a strong resistance of tensile stress due to traffic loading. CONCLUSIONS: Based on limited laboratory test result, a performance of crack resistance using the sealing tape is better than that of general tack coat material(RSC-4). It means that the sealing tape is possible to extend a pavement service life because the crack, one of the main pavement distresses, will be delayed. Keywords Sealing Tape, Crack Resistance, Freeze-Thaw, Tensile Adhesion
        4,000원
        38.
        2018.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        급성 췌장염은 췌장의 염증성 질환으로 췌장성 복수 및 가 성 낭종과 같은 합병증을 일으킬 수 있다. 이러한 합병증은 심할 경우 결장, 복막 및 장간막의 이차성 변화를 일으켜 복막암 종과 구별하기 어려울 수 있다. 본 증례의 환자는 타 병원에 서 급성 췌장염 및 합병증으로 발생한 가성 낭종을 치료하는 도중 복막암의 가능성이 있어 추가 평가를 위하여 본원으로 전원되었다. 복막암의 가능성을 배제하기 위한 복막 조직검사 없이 순차적인 시술적 접근을 통하여 췌관의 손상으로 발생한 췌장성 복수와 가성 낭종으로 진단할 수 있었다.
        4,000원
        39.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of pasture grazing and barn feeding system on the growth performance, weight gain and velvet antler productivity in Elk. Twelve 5-year-old elk stags about 273 kg were stratified by weight and randomly assigned by feeding system (a pasture grazing and a barn feeding, n=6). The average feed intake were not signigicant difference between two groups. Average daily gain for grazing and barn feeding group was 0.25 g and 0.29 g respectively, showing no significant difference. Velvet antler yield for grazing and barn feeding group was 7,700 g and 6, 960 g respectively, with no significant difference. In conclusion grazing group was better than barn feeding group in feed intake, body weight gain and velvet antler productivity. However, there were no statistical significant difference between the two group. These results may serve as the basis for further study of deer feeding system in Korea and further study needed to examine the grazing intensity and economic efficiency.
        4,000원
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