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        검색결과 122

        41.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The most important role of air defense system is to attack the air target of enemy to defend the important military unit or facilities. In order to attack the target as soon as it is detected, fast and precise fire signal transfer using the fire control stick is very important. However, it was found that firing is not conducted in the test for fire control stick. In order to find the reason of such problem and improve life cycle of fire control stick, the test was conducted and it was found that chattering occurred and this led to malfunction of signal transfer from control stick to fire control unit of air defense system. In order to draw resolution for this problem, two contact plate made of beryllium copper is suggested to add to the control stick to enhance the contact and reduce chattering effect. The four fire switch prototypes were tested for 100,000 times and it showed its reliability of use.
        4,000원
        42.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In case vehicle system has low travel distance and short duration of engine operation, this can be relatively susceptible to engine scuffing related problem. Users also experience inconvenience in system maintenance that they have to manually start engine periodically in cold night during winter. In order to solve such problems and improve system's life cycle, the automatic engine start system is developed. In order to develop the automatic engine start sytem for air defense system BIHO, two types of engine start sytem and the engine sub system are studied and four steps to start and control the automatic engine start system is suggested. The prototype of automatic engine start system was tested for the single assembly and vehicle-installed test and all requirement of the system was madeto prove its possible application.
        4,000원
        43.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Air Defense System requires fast movement of the turret to detect and attack the flying target of enemy. In order for the air defense system to operate accurately and properly, it is necessary to optimize the design of the motor brake system. The air defense system that is not designed properly has possibility of low performance of the gun turret and environment of operators. The previous air defense system had such flaw in its design and it caused much noise and current in the operation of the turret. In order to resolve this flaw, we changed the position and design of the components of the motor brake system to reduce load and achieved the 62.5% reduced current and 40% reduced noise of the motor brake system compared to the previous design.
        4,000원
        45.
        2019.04 구독 인증기관·개인회원 무료
        Here, we investigated antioxidant defense mechanism in the spermatheca of A. mellifera queens via RNA-seq analysis of spermathecae in both mated and virgin queens. We identified the genes encoding antioxidant proteins, which were differentially expressed in the spermatheca of mated queens. The concentrations of antioxidant proteins, such as superoxide dismutase 1 (SOD1), catalase, glutathione peroxidase (GTPX), and transferrin (Tf) together with the levels of ROS, H2O2, and iron were higher in the spermathecal fluid of mated queens as opposed to those in the spermathecal fluid of virgin queens; this indicated that increase in antioxidant protein concentration is an antioxidant defense mechanism occurring in the spermathecal fluid of mated queens against ROS; this mechanism involves conversion of ROS using antioxidant enzymes and Tf-mediated inhibition of the Fenton reaction occurring between Fe2+ and H2O2. Our data indicate that an increased expression of antioxidant proteins could facilitate prolonged storage and survival of sperms in the spermatheca of mated queens, suggesting the role of antioxidant proteins in antioxidative defense against ROS.
        46.
        2019.04 구독 인증기관·개인회원 무료
        South Korea has over 0.38 million of managed honey bee (Apis cerana) colonies before 2009 years ago, which produce the highest quantity of honey in the Korea; however, almost colony (90%) were collapsed by Korean Sacbrood Virus (KSBV) in South Korea. Korean Sacbrood Virus (KSBV) is the pathogen of A. cerana Sacbrood disease, which poses a serious threat to honeybee A. cerana, and tends to cause bee colony and even the whole apiary collapse. Colony collapse of A. cerana was first reported on the Pyeong-Chang of the South Korea in 2009. Several scientists and governments has been tried research for cure the sacbrood disease in A. cerana colony by medicines and management techniques. Unfortunately, The sacbrood disease dosen’t improve. So, we were developed a better breed of A. cerana for resistance of sacbrood virus by selection and then artificial insemination. A. cerana breeding technique was first successful applied with A. cerana in Korean. Queens was grafted from sacbrood resistance line and then it was growing in sacbrood disease colony that was survived 100%. Altogether selected 18 queens were artificially inseminated and 2,000 drones of A. cerana in Korea was used to evaluate amount of semen collection. We are select two scabrood resistance A. cerana line (R and H). R line be used for rearing the Queen. Drone was reared in H line colony. The RH hybrid were not infected sacbrood virus even spread sacbrood virus (2×106). RH colonies have very excellent hygienic behavior, brood, and sacbrood disease resistance activity.
        47.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bisphenol A (BPA), a representative endocrine disrupting chemicals, has adverse effects on growth, development and reproduction in aquatic organisms. The object of this study was to investigate the modulation of antioxidant enzyme - coding genes using quantitative real time RT - PCR (qRT - PCR), enzyme activity and total protein content, to understand oxidative stress responses after exposure to BPA for 48 h in brackish water flea Diaphanosoma celebensis. The BPA (3 mg L-1) significantly upregulated the expression of Cu / Zn - SOD, Mn-SOD, and catalase (CAT ) mRNA. Three GST isoforms (GST-kappa, GST-mu, and GST-theta) mRNA levels significantly increased at the rate of 0.12 mg L-1 of BPA. In particular, GST-mu showed the highest expression level, indicating its key role in antioxidant response to BPA. SOD activity was induced with a concentration - dependent manner, and total protein contents was reduced. These findings indicate that BPA can induce oxidative stress in this species, and these antioxidants may be involved in cellular protection against BPA exposure. This study will provide a better understanding of molecular mode of action of BPA toxicity in aquatic organisms.
        4,000원
        48.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 중국의 국방·안보백서 발간의 추이와 함의를 분석하기 위한 것이다. 이를 위해 중국의 국방·안보백서의 발간경위 및 구성, 시진핑 시기의 국방·안보백서의 요지와 함의의 순서로 살펴본 후 결론을 도출해 본 것이다. 중국 국방부는 1998년 이후 2010년까지 2년 주기로 7권의 『중국의 국방』을 발간했다. 그리고 중국 국방부는 이미 1995년 국방관련 주제의 백서 『중국의 무기통제와 군축』을 처음 발간한 데 이어, 2013년 『중국 무장역량의 다양한 운용』, 2015년 『중국의 군사전략』의 3권의 국방관련백서, 그리고 2017년 『중국의 아시아·태평양 안보협력정책』이라는 1권의 안보백서를 발간했다. 모두 중국의 전략적 계산을 반영한 프로파간다라는 공통적 특징을 지니고 있다. 중국이 전향적으로 국방백서를 발간하기 시작한 데는 ①미국 등 주변국의 군사적 투명성 요구에 대한 압력, ②‘중국위협론’의 불식, ③중국의 군사 현대화의 성과에 대한 자신감 등 복합적 요인이 작용한 것으로 보인다. “중국의 꿈은 강국의 꿈이고 강국의 꿈은 강군건설이 필수이다.”라는 시진핑의 의지가 담긴 ‘적극적 방어전략’ 및 강대강전략은 주변국에게 안보적 우려감을 증폭시키고 있다. 튼튼한 한·미 안보공조관계를 유지·강화해 나가는 한편, 한중경제협력관계도 조화롭게 추진해 나가는 헤징전략이 우리에게 요구된다.
        8,700원
        51.
        2018.10 구독 인증기관·개인회원 무료
        애벌레의 번지점프는 포식자로부터 몸을 지키기 위한 방어 전략이다. 본 연구는 애벌레가 어떠한 감각 자극에 반응하여 번지점프를 하는지 확인하기 위한 연구이며, 본 연구를 수행하기 위해 2018년 목포대학교 승달산 부근에서 애벌레를 채집하여, 시각(애벌레 시야로 접근), 바람(일정한 세기를 위해 선풍기를 이용한 바람), 촉각(애벌레의 몸을 나뭇가지로 자극)에 대한 반응(번지점프)을 조사하였다. 조사결과 28종 78마리의 애벌레가 방어 전략으로 번지점프를 사용하였다. 또한 애벌레의 자극에 대한 번지점프를 비교해 본 결과 시각, 바람에 반응을 보이는 빈도수가 촉각에 비해 현저하게 적게 나타나는 것을 실험적으로 확인하였다. 애벌레의 번지점프가 포식자로부터 몸을 지키기 위한 생존전략이라는 것을 추가적으로 검증하기 위해 포식자(개미로 가정)가 접근 시 발생하는 진동(포식자가 접근할 때 표면에 나타나는 진동)과 포식자와의 접촉(개미가 애벌레에 접촉)에 대한 애벌레의 반응을 조사하였다. 실험 결과 포식자가 접근 시 발생하는 진동보다는 포식자의 접촉(촉각)이 애벌레의 번지점프를 유도한다는 사실을 확인하였다. 두 실험결과에서 간접적인 자극인 시각, 바람, 진동보다 직접적인 자극인 촉각에 보이는 반응이 현저하게 높게 나타난다. 이는 애벌레의 번지점프는 애벌레와 포식자의 접촉이후 보이는 최종적인 애벌레의 방어 전략이라는 것을 시사하고 있다.
        52.
        2018.10 구독 인증기관·개인회원 무료
        Many insects are able to feed on crucifers despite the presence of a potent activated defense system known as the mustard oil bomb. In damaged tissue, mustard oil glucosides (glucosinolates) are hydrolyzed by the enzyme myrosinase to form toxic mustard oils (isothiocyanates). Here, we analyzed how the the cabbage stem flea beetle Psylliodes chrysocephala, a key pest of oilseed rape, copes with this chemical defense. First, we found that P. chrysocephala prevents the activation of ingested glucosinolates by two different strategies, a) by sequestering glucosinolates and b) by converting glucosinolates to desulfo-glucosinolates. Our next aim was to identify the sulfatase enzyme(s) responsible for the detoxification of glucosinolates in P. chrysocephala. Nine arylsulfatase-like genes were identified in the transcriptome of P. chrysocephala, and five of them showed glucosinolate sulfatase activity upon heterologous expression in Sf9 cells. By using RNAi, we confirmed that PcGSS1 and PcGSS2 are active towards benzenic and indolic glucosinolates in P. chrysocephala adults in vivo. However, in feeding experiments, the proportion of sequestered and desulfated glucosinolates ranged from 26 to 35% which suggests that these strategies alone are likely not sufficient to overcome the chemical plant defense. Indeed, P. chrysocephala additionally conjugates isothiocyanates to glutathione and metabolizes them via the conserved mercapturic acid pathway. In summary, the cabbage stem flea beetle avoids isothiocyanate formation by specialized strategies (sequestration and desulfation), but also relies on a conserved detoxification pathway to prevent toxicity of isothiocyanates.
        53.
        2018.10 구독 인증기관·개인회원 무료
        Many herbivorous insects sequester plant defense compounds from their host plants to protect themselves from natural enemies. In plants, these defense compounds are often stored as protoxins separated from their activating enzymes. A well-known example is the glucosinolate-myrosinase defense system in plants of the order Brassicales. When plant tissue is ingested by herbivores, glucosinolates are hydrolyzed by the enzyme myrosinase to form highly reactive isothiocyanates. We previously reported that flea beetles of the genus Phyllotreta selectively sequester high amounts of glucosinolates from their crucifer host plants, and convergently evolved their own myrosinase which enables them to utilize sequestered glucosinolates for their own purposes (Beran et al., 2014). The presence of intact glucosinolates in these beetles suggests that despite tissue damage, ingested glucosinolates are not activated by the plant myrosinase. Rapid and efficient glucosinolate uptake from the gut lumen into gut epithelial cells can prevent hydrolysis and thus might be crucial to overcome this activated plant defense. We use the horseradish flea beetle Phyllotreta armoraciae as a model to study the molecular basis of sequestration in insects. In short-term feeding experiments, we showed that ingested glucosinolates are rapidly sequestered in the foregut. To identify the transporters that mediate glucosinolate import from the foregut lumen into gut epithelial cells, we focused on the MFS transporter family, which is known to transport a wide range of substrates. A phylogenetic analysis of putative MFS transporter sequences identified in P. armoraciae and other beetles revealed several specifically expanded clades in P. armoraciae. Out of 21 candidate genes that were heterologously expressed in Sf9 cells, nine showed glucosinolate transport activity in vitro. Interestingly, most candidate genes were exclusively expressed in the malpighian tubules, and two genes were additionally expressed in the foregut. We currently elucidate the function of these transporters in glucosinolate sequestration in vivo using RNAi. To better understand the function of sequestered glucosinolates, we performed bioassays with P. armoraciae larvae and the generalist predatory ladybird Harmonia axyridis. Upon predator attack, P. armoraciae larvae emitted high amounts of isothiocyanates and ladybird larvae stopped feeding within a few seconds and were highly irritated. However, silencing myrosinase gene expression in P. armoraciae larvae led to increased mortality compared to control larvae in survival assays with ladybird larvae. Our results demonstrate how Phyllotreta use plant defense metabolites to defend themselves against predators.
        54.
        2018.05 구독 인증기관·개인회원 무료
        최근 몇 년 사이에 가장 화두가 되는 단어는 단연 4차 산업혁명일 것이다. 인공지능, 가상/증강현실 구현, 모바일, 빅데이터 등 최신 ICT 기술은 인류 삶의 패러다임을 완전하게 바꾸어 놓았다. 이런 ICT기술의 진보는 국방분야에도 많은 영향을 미쳤고 이에 가장 민감하게 반응하고 변화하고 있는 분야가 국방 M&S분야일 것이다. 기술의 진보에 따라 사회환경이 변하듯 전장환경도 빠르게 변하고 있는 상황에서 본 주제발표에서는 미래를 예측하고 준비하는 국방 M&S분야의 현 주소와 발전방향을 제시하고자 한다.
        55.
        2018.04 구독 인증기관·개인회원 무료
        Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host-selection behaviors are often consistent with the preference-performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically-relevant interactions. In this time, I will talk about the host-selection behaviors of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field- and glasshouse-experiments with transgenic host plants specifically altered indifferent components of their secondary metabolism. In addition, I will show that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions.
        56.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the defense acquisition, a company’s goal is to maximize profits, and the government’s goal is to allocate budgets efficiently. Each year, the government estimates the ratio of indirect cost sector to defense companies, and estimates the ratio to be applied when calculating cost of the defense articles next year. The defense industry environment is changing rapidly, due to the increasing trend of defense acquisition budgets, the advancement of weapon systems, the effects of the 4th industrial revolution, and so on. As a result, the cost structure of defense companies is being diversifying. The purpose of this study is to find an alternative that can enhance the rationality of the current methodology for estimating the ratio of indirect cost sector of defense companies. To do this, we conducted data analysis using the R language on the cost data of defense companies over the past six years in the Defense Integrated Cost System. First, cluster analysis was conducted on the cost characteristics of defense companies. Then, we conducted a regression analysis of the relationship between direct and indirect costs for each cluster to see how much it reflects the cost structure of defense companies in direct labor cost-based indirect cost rate estimates. Lastly a new ratio prediction model based on regularized regression analysis was developed, applied to each cluster, and analyzed to compare performance with existing prediction models. According to the results of the study, it is necessary to estimate the indirect cost ratio based on the cost character group of defense companies, and the direct labor cost based indirect cost ratio estimation partially reflects the cost structure of defense companies. In addition, the current indirect cost ratio prediction method has a larger error than the new model.
        4,000원
        57.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        사회적으로 안전에 대한 관심이 많아지고 있는 상황에서 계속되는 북한의 미사일 실험은 이를 대비한 민방위 대피시설의 운영 실태를 점검하는 계기가 되었다. 본 연구에서는 공간 최적화 접근을 통하여 개별 대피시설 수준에서 서비스 커버리지와 수용 능력을 평가하였다. 특히 수요를 상주인구로 재현하였을 때와 현주인구로 재현하였을 때 모델링 결과가 어떻게 달라지는지 분석하였다. 사례지역으로 대구광역시 서구의 민방위 대피시설의 커버리지를 평가하였다. 그 결과, 지정된 민방위 대피시설에 의해서 커버되지 않은 현주인구가 상주인구에 비하여 절대적으로 뿐만 아니라 상대적으로 많았다. 또한 기존 대피시설에 의해서 커버되지 않는 상주인구와 현주인구의 위치가 달랐다. 마지막으로 개별 대피시설에 할당된 인구를 수용가능 인구와 비교해 본 결과 대체로 시설의 규모가 클수록 실제 수용률이 낮게 나타났다. 이러한 공간 최적화 접근을 통하여 도출한 정보는 재난관리를 보다 구체적이고 체계적으로 만드는데 기여할 것이다.
        4,300원
        60.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Defense industries which require high reliability need an optimized quality management system with well-planned implementation. And the government should examine the overall status of defense industries, then establish practical policies with a proper support plan in required areas to upgrade the quality management level of manufacturers. Thus, DTaQ developed the model for 2 years from 2014, which specialized in quality management level analysis for defense industries. And a survey has been undertaken with that model by DTaQ and Korea Research Center in 2016. The surveyed companies randomly sampled among those which have more than 30 employees and delivery history over past 3 years, and finally 106 defense industries were selected. This paper present survey method and indexes for survey of defense industry quality management level. The survey was conducted in the order of planning, data collection and data processing, and the validity and reliability of the data were verified to increase objectivity of survey results. The survey contents mainly consist of system quality and management quality. System quality includes Product Development Management, Production Operation Management, supply chain quality management, Safety & Environment Management and Reliability Management, on the other hand, management quality includes Strategic Leadership, Human Resource Management, Customer Market Management and Information & Knowledge Management. Thus this proposes the current overall quality management status of the 106 defense industries and shows level differences by company sizes and manufacturing sectors based on the result of survey. Specifically, this paper enables to track the areas which need prompt government support with the policy directions to make quality management level higher. Therefore, it is expected that this can be used as reference data in establishing quality policies for military supplies in the future.
        4,000원
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