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        검색결과 1,271

        341.
        2018.05 구독 인증기관·개인회원 무료
        Ground depression/cave-ins due to subsurface cavities have been occasionally occurred in urban area. To prevent the ground cave-ins, a ground penetrating radar (GPR) method was applied and more than 2,000 subsurface cavities were found in Seoul. For each cavity, excavation was carried out to investigate main cause of the cavity and then the site was restored permanently. It was found that this excavation-and-restoration method was not efficient to repair small size cavities. Instead, grouting methods was used to repair the small cavities temporarily. This study evaluated the field applicability of grouting methods on restoring small cavities. Three types of grouting materials were applied on 12 sections and two non-destructive tests were conducted in field. A falling weight deflectometer(FWD) test was conducted to assess the bearing capacity of the site before and after grouting. Ground penetrating radar (GPR) was used to evaluate the extent of the grouting materials to a cavity. From the FWD test results, the bearing capacity of the Section A and B was enhanced by 7.5% and 13.5% while the bearing capacity of the section C was reduced by 11.5%. It was found from the GPR tests that the grouting materials used in the Section B and C could fill the cavity well and also extended to surrounded area due to injection pressure or selfexpansion. In common, the small cavities could be restored quickly, less than 30 minutes per a cavity by the grouting methods. Hence it can be concluded that the grouting methods can be applicable to restore small cavities. However, it needs to consider the application of grouting methods carefully because the grouting methods can be lost through a pipe link to a cavity. Also, excavations can be conducted occasionally in urban roads so that the stiffness of grouting materials needs to soft enough to be excavated and strong enough to support traffic loads.
        343.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        긴급하거나 광역으로 발생한 해상유류오염사고에는 방제정만으로 대응하기에는 한계가 있어서, 해양경찰청 경비함정도 방제 작업에 동원된다. 본 연구에서는 소형 경비함정에 적합한 유흡착장비를 개발하였다. 장비는 고정지지대, 폴대, 슬라이드고정부 3개 부속품으로 구성되어 용접 또는 추가 구조물 설치 없이 소형 경비함정 현측 추락방지봉에 간단하게 토글핀으로 결속하는 방식으로 장착 및 분리가 가능하다. 각 부속품의 무게는 고정지지대 약 9.2 kg, 폴대(2개) 약 6.5 kg, 슬라이드 고정부(4개) 약 3.5 kg이며, 좌·우 180°로 원활하게 움직이는 길이 3 m의 폴대는 갑판 방향으로 접어서 유흡착재 교체작업을 할 수 있다. 본 장비의 개발로 소형 경비함정에서 유흡착재의 투입 및 수거가 용이한 방법으로 개선되어 보다 효율적인 방제작업이 가능할 것으로 판단된다.
        4,000원
        345.
        2018.04 구독 인증기관·개인회원 무료
        Small hive beetle (Aethina tumida) (SHB) is an invasive species to most northern hemisphere countries, including Korea. In an attempt to obtain basic information for efficient management of SHB, genes encoding conventional insecticide targets [voltage-sensitive sodium channel α-subunit (VSSC) and acetylcholinesterase (AChE)] were annotated and characterized following the analysis of whole transcriptomes of adults and larvae. A single VSSC gene was identified but no apparent mutations associated with pyrethroid resistance were detected. Genes encoding two AChEs (AtAChE1 and AtAChE2) were identified from the SHB transcriptome. AtAChE1 was determined to be the main catalytic enzyme, thereby being a toxicologically more relevant target. No apparent mutations associated with resistance to organophosphorus and carbamate insecticides was identified in the AtAChE1 gene, whereas the S238G mutation, originally identified from the Colorado potato beetle, was detected in the AtAChE2 gene.
        346.
        2018.04 구독 인증기관·개인회원 무료
        One of the leading pests of rice, small brown planthopper (Laodelphax striatellus) can grow up to have either short or long wings, depending on conditions. However, under the same breeding conditions, the phenotypes of the long- and short-winged small brown planthopper observed to keep the first collected phenotype. To investigate the mechanism involved in wing dimorphism, metabolomic researches have been conducted. In this study, we observed several metabolites change, and the difference of metabolites could provide clues to the relationship between physiological changes in the small brown planthopper and ecological transport.
        347.
        2018.04 구독 인증기관 무료, 개인회원 유료
        정부와 안전보건공단에서는 건설현장의 안전사고를 줄이기 위하여 감독․점검, 기술지도, 재정지원 등의 산업재해예방 활동을 지속적으로 수행하여 왔다. 하지만, 전체 산업의 사고사망만인율과 재해율이 전반적으로 감소 추세에 있는 반면에, 건설업의 사고사망만인율 및 재해율은 2014년 이후 오히려 증가 추세에 있다. 특히, 2016년 재해통계를 기준으로 전체 건설업 재해자의 약 70%가 공사금액 20억 미만의 소규모 건설현장에서 발생하였다. 이러한 소규모 건설현장의 재해를 줄이기 위해서는 현재의 산업안전보건법 상의 소규모 건설현장 산업안전보건관리체제와 고용노동부 및 안전보건공단에서 수행하고 있는 소규모 건설현장재해예방 사업에 대한 실효성을 파악하고 개선할 필요가 있다. 현 산업안전보건관리체제에서는 건축공사 기준으로 120억 이상인 공사인 경우 안전관리자를 의무 선임하도록 되어 있으며 3억에서 120억 미만 공사의 경우 재해예방지도기관의 기술지도를 받도록 되어 있다. 또한, 안전보건공단에서는 민간위탁기관을 지정하여 3억 미만 건설공사의 안전관리를 지원하고 있으며, 클린사업장 조성지원사업을 통해 20억 미만 소규모 건설현장의 추락재해예방을 위해 시스템 비계, 사다리형 작업발판 및 안전방망 등의 설치 비용을 지원하고 있다. 본 연구에서는 공사금액별 재해통계 및 안전관리자 선임관련 제도를 분석하여 안전관리자 선임 대상을 현행 건축공사 120억 이상인 공사에서 단계적으로 50억까지 확대할 것을 제안한다. 설문조사와 전문가 의견을 수렴하여 재해예방지도기관의 기술지도 영역을 조정하고 실효성을 강화하기 위한 방안을 수립하고, 클린사업장 조성지원사업의 사업 확대 요구 및 개선사항을 도출한다.
        4,600원
        348.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cellular cyclic adenosine-3’ 5’-monophosphate (cAMP) modulator is known as meiotic inhibitor and can delays spontaneous maturation in IVM experiment. Among many cAMP modulators, the role of Pituitary adenylate cyclase activating polypeptide (PACAP) on IVM isn’t known. The purpose of this study is to improve the maturation of oocytes derived from follicles ≤ 3 mm in diameter through PACAP as meiotic inhibitor during pre-in vitro maturation (pre-IVM). First, we checked PACAP and its receptors in cumulus cells and, to establish the optimal phase and concentration of PACAP for pre-IVM, we conducted chromatin configuration assessments. As a result, the rate of GV (Germinal Vesicle) according to duration of pre-IVM was significantly decreased 12 h and 18 h after IVM (87.1 and 84.1%, respectively) compared to 0 h (99.4%). When COC was cultured for 18 h, the GV rate in the 1 μM of PACAP treatment group (82.1%) was significantly higher than any other PACAP treatment groups (60.5, 64.1, 74.4 and 69.9 %, respectively). So, we divided into four groups as follows; MF (the conventional IVM group, obtained from follicle from 3 to 6 mm in diameter), SF (the conventional IVM group, obtained from follicle ≤ 3mm in diameter), Pre-SF(-)PACAP (IVM group including 18 h pre-IVM without 1 μM of PACAP, obtained from follicle ≤ 3mm in diameter) and Pre-SF(+)PACAP (IVM group including 18 h pre-IVM with 1 μM of PACAP, obtained from follicle ≤ 3mm in diameter). To examine the effect of PACAP during pre-IVM, we investigated analysis of nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels. In cumulus cells, PACAP receptors, ADCYAP1R1 and VIPR1 were detected but were not detected in oocytes. After IVM, the Pre-SF(+)PACAP had the highest Metaphase II rate (91.7%) among all groups (P<0.05). The GSH levels in the MF and Pre-SF(+)PACAP were significantly higher than in the other groups (P<0.05) and ROS levels was no significant difference among all groups. In conclusion, these results indicated that even though the oocytes were derived from SF, pre-IVM application of PACAP improved meiotic and cytoplasmic maturation by regulating intracellular oxidative stress.
        4,200원
        349.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To enhance the physiological activity of the Rhynchosia volubilis (RV), R. volubilis (RVHE-A) and R. volubilis-added herbal powder (RVHE-B) were fermented with a solid state culture of Hericium erinaceum mycelia (HE). The total isoflavone contents of the non-fermented RV-A (489.9 μg/g) and RV-B (571.1 μg/g) were remarkably increased in fermented RVHE-A (1,836.4 μg/g) and RVHE-B (1,276.7 μg/g). In particular, aglycone isoflavones such as daidzein and genistein were significantly higher in the RVHE-A than any other sample. When hot-water (HW) and EtOH extracts (E) were fractionated from the RV and RVHE, both extracts from the RVHE-A were higher than those from the RV-A in total polyphenol and flavonoid contents. However, the RVHE-B-HW showed a lower polyphenol and flavonoid content level than did RV-B-HW. RVHE-A-HW and -E also had more potent ABTS radical scavenging activity than any extract from the non-fermented RV and other ferments (RVHE-B). In the meanwhile, RVHE-A-HW potently stimulated the production of macrophage activation-related cytokines such as TNF-α, IL-6 and IL-12 (841.7±71.3 pg/mL, 3.9±0.1 ng/mL, 179.3±30.2 pg/mL) from peritoneal macrophage more than RV-A-HW (92.5±1.5 pg/mL, 0.1±0.0 ng/mL, 37.4±5.4 pg/mL) as well as RVHE-B-HW (557.0±21.3 pg/mL, 1.8±0.0 ng/mL, 90.0±10.0 pg/mL). However, all the EtOH extracts did not show significant activity. In addition, the RVHE-A-HW showed a significantly higher intestinal immune system modulating activity through Peyer’s patch and GM-CSF production than did any other extract from RV and RVHE-B. In conclusion, these results suggest that the fermented R. volubilis with H. erinaceum mycelia possesses a possible use as an industrial application as functional food or material.
        4,200원
        350.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the outboard engine system of internal combustion engine is widely used in the field of small ship propulsion. However, the internal combustion engine has serious problems of energy depletion and environmental problems, so electric propulsion methods are being studied. In this paper, we have developed important motors and controllers of electric propulsion system for small marine outboard motors. The motor design was performed through the motor characteristics analysis method, and the 30Kw system was developed through the BEMF processing circuit and the power conversion circuit by the embedded microprocessor. This study was carried out through government supported projects and achieved quantitative targets through accredited institutions.
        4,000원
        351.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In knowledge information society entering global unlimited competition era, our middle and small sized companies are the base of national and enterprise competitiveness and core base of national economy as an origin of jobs. The competitiveness of middle and small sized companies is so important to decide the level of the competitiveness of the whole industries, but the gap from big sized company is much low in comparison with advanced countries from angles of important factors of enterprise growth, productivity and technological competitiveness, so, it's urgent to improve the competitiveness through productivity enhancement. The purpose of this research is to do a positive study on effects of learning organization management outcomes of middle and small sized company on enterprise productivity among various types of outcome brought for strengthening of enterprise competitiveness. It confirmed learning organization has functions and usefulness as a management tool bringing positive effects on enterprise productivity through the Productivity improvement.
        4,000원
        352.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this experiment was to determine the effect of supplementation of hot melt extrusion (HME) processed Zn sulfate on growth performance, nutrients digestibility, small intestinal morphology and excretion of Zn in weanling pigs. A total of 200 piglets of mixed sex randomly allotted to four treatments on the basis of initial BW (7.15±0.81 kg). There were five replicates in each treatment with 10 pigs per replicate. The experimental treatments consisted of: 1) basal diet containing ZnSO4; 2) basal diet containing Zn-Methionine (ZnMet); 3) basal diet containing low level of nano-Zn as HME (ZnHME50); 4) basal diet containing medium level of nano-Zn as HME ZnSO4 (Zn-HME75). The average daily gain was improved by the ZnMet and ZnHME75 compared with the pigs fed ZnSO4 supplemented diets (p=0.009). Moreover, ZnHME75 and ZnMet affected on the ATTD of CP during phase 2 (p=0.014). The villus height (VH) was affected by increasing when pigs fed diets supplemented the ZnHME75 (P=0.044). The pigs fed diets supplemented ZnHME50 had significantly the lowest (p=0.037) Zn content in liver compared with other treatments. The Zn content in the feces was significantly higher (p<0.001) in ZnSO4 and ZnMet compared with ZnHME50 or ZnHME75. In conclusion, it could be concluded that dietary Zn can be reduced by 25% with ZnHME without any detrimental effect on performance of weanling pigs.
        4,200원
        353.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the advent of the fourth industrial revolution, the digital transformation craze has intensified in diverse industries, such as finance, automotive, health care and agriculture. However, relative to industry demand, there is only few domestic research on digital transformation of small traders and no one has implemented empirical study on this field at all. Thus, the study conducted an empirical study to measure the digital transformation intention of domestic small traders. In the early days of domestic business start-ups, we searched for factors affecting the digital conversion intention of small business owners and designed an integrated framework to explain the causal relationship between factors. This study not only expanded and refined the scope of related research but also suggested the direction of another research that was not presented in previous research. However, there are limitations in many ways as much as the initial stage of a specific field of small business owners. There are limitations in explaining the overall perception of Korean small business owners. Therefore, in future studies, it is necessary to study more deeply by presenting more specific and various variables. In addition, although the number of respondents was sufficient in the process of empirical analysis, it is considered that the respondents are not enough to universalize the research result as a traditional small business person who did not convert all digital. It is necessary to carry out a comparative analysis by dividing the two groups in more detail and more specifically in the future study. The result of this study can suggest the direction for accelerating small traders’ digital transformation intention in terms of practical view, and provide useful references which can support the theoretical foundation for researchers who will perform future related research in terms of academic view.
        4,200원
        354.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the competitiveness of SMEs (small and medium enterprises) is getting more and more improved and globalized, the government provides various consulting services to secure the competitiveness of small and medium firms and support stable growth. However, the assessment of the result from the government’s support is generally focused on non-financial factors, such as customer satisfaction and analysis of improvement effect. This paper is in regards to the statistical analysis of how much the government’s support in the form of providing consulting services contributes to financial outcomes in terms of profitability and growth. ROA (return on asset) and ROS (return on sales), which are investment profitability and sales profitability respectively, are chosen as an indicator of profitability. For analysis of growth, sales revenue and total asset growth are used. The samples are 44 corporations which are supported by government, and 150 corporations which are selected for comparison, with corporate growth support center program by the Ministry of Trade, Industry, and Energy chosen as the consulting model. After gathering the yearly balance sheets and income statements of the samples from CRETOP, Korea Enterprise Data, the analysis is conducted in the way of identifying the statistical significance of financial difference in the same period between corporates taking consulting services and corporates which have not, and the difference of financial outcomes from the corporates taking consulting services before and after consulting services. As a result, in terms of business growth, it is turned out to have positive difference both in growth ratio and profitability compared to the compared corporations at the significant level. Therefore, it is obvious that the consulting program which government provides to SMEs have direct influence practically to the corporates’ management performance.
        4,000원
        355.
        2017.12 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 전도성 고분자인 polystyrene sulfonic acid doped poly~3,4-ethylenedioxythiophene (PEDOT:PSS)을 소스/드레인 전극으로 사용한 펜타센 단분자 유기 반도체 기반의 전계효과 트랜지스터를 제작하고, 금을 소스/드레인 전극으로 하는 기준소자와 전기적 특성을 비교하여 평가하였다. 전기적 특성을 측정한 결과, PEDOT:PSS 박막은 금 박막에 비해 상대적으로 낮은 전도도를 가짐에도 불구하고 PEDOT:PSS 소스/드레인 전극을 갖는 펜타센 유기 트랜지스터는 금을 소스/드레인 전극으로 갖는 기준 소자와 비교할 만한 성능을 보였다. 이는 PEDOT:PSS와 펜타센 사이의 접촉저항이 금과 펜타센 사이의 접촉저항보다 낮아 상대적으로 낮은 전기전도도에 의한 성능 저하를 보상하기 때문으로 추측된다.
        4,000원
        359.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 ICT 분야 중소기업의 외부환경 민감도와 혁신활동에 대한 조직성향 이 기업성과에 미치는 영향요인에 대해 실증분석하였다. 분석방법으로는 첫째, 탐색적 요인 분석(Exploratory Factor Analysis)을 통해 투입된 변수간의 관계성과 패턴을 파악하였고 둘 째, 요인분석에 의해 축약된 영향 요인들을 유형화하는 군집분석(Cluster Analysis)을 실시 하였다. 마지막으로 유형화된 군집들의 혁신활동과 기업성과간 구조적 관계를 규명하고자 구조방정식모형(Structural Equation Modeling)을 이용하여 분석을 실시하였다. 본 연구는 국내 ICT분야 중소기업을 대상으로 실시한 E-연구원의 수요조사 결과 1,022부에 대해 실증 분석에 활용했다. 내⋅외부 환경에 대한 40개 투입변수에 대해 탐색적 요인분석을 실시한 결과, 총 7개의 요 인이 추출되었으며 7개의 요인을 기반으로 총 4개의 군집(n=1,022)이 형성되었다. 군집 4개 의 대해 구조방정식 모형을 활용하여 실증분석을 한 결과, 기술⋅경쟁 환경에 민감하며, 혁 신적인 조직 성향을 가진 군집1은 자체기술개발만이 기업성과에 긍정적 영향을 미치는 것으 로 나타났다. 시장 환경에 민감하며, 내부 협력적 조직 성향을 가진 군집2는 자체기술개발과 공동연구를 통해서만 기업성과에 긍정적 영향을 미치는 것으로 나타났다. 경쟁적인 환경에 민감하며, 혁신적이고 정부/관련기관과의 협력적 조직 성향을 가진 군집3은 공동연구 그리고 매개변수인 정부 지원 프로그램 활용을 통해 기업성과에 긍정적 영향을 미치는 것으로 나타 났으며, 기술도입은 기업성과에 부정적 영향을 미치는 것으로 나타났다. 개방적인 조직 성향 이 강한 군집4는 자체기술개발과 매개변수인 네트워크 활용 및 정부 지원 프로그램 활용이 기업성과에 긍정적 영향을 미치는 것으로 나타났다. 본 연구의 결과는 중소기업 혁신을 위한 전략 및 정책 수립에 유용하게 활용될 수 있을 것이다.
        8,600원