• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.150-156
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• 2004

Though the concept of Life-Cycle Cost (LCC) itself is not new, its effectiveness for planning, design, rehabilitation and maintenance/management of civil infrastructures is becoming increasingly recognized. For the decision problems as in the case of the LCC of plant facilities, equipments, bridge decks, pavements, etc., the Life-Cycle Cost Analysis (LCCA) is relatively simple, and thus its practical implementation is rather straightforward. However, when it comes to major infrastructures such as bridge, tunnels, underground facilities, etc., the LCCA problem becomes extremely complex because lack of cost data associated with various direct and indirect losses, and the absence of uncertainty data available for the assessment as well. As a result, the LCC studies have been largely limited only to those relatively simple LCCA problems of planning or conceptual design for making decisions. Accordingly, in the recent years, the researchers have pursued extensive studies on the LCC effectiveness mostly related to LCC models and frameworks for civil infrastructures. Moreover, recently the demand on the practical application of LCC effective decisions in design and maintenance is rapidly growing unprecedently in civil engineering practice. Indirction cost is very important on LCC formulation. But that is very difficult and complicate the estimation every LCC. The objective of this paper is to suggest efficient regression model for the estimation of indirect cost approach to the practical application of LCC for the design and rehabilitation of civil. infrastructures considering traffic, traffic network, detour condition, and workzone condition. In this paper, it performed the sensitivity analysis and correlation analysis of parameter for development of regression model of inflection cost.

• 한국컴퓨터정보학회논문지
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• 제10권5호
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• pp.187-198
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• 2005

본 논문에서 차세대 IP 네트워크인 Ipv6에서의 효율적인 데이타 전송을 위한 헤더압축 기법을 제안하고자 한다. 기존의 네트워크와 최근 각광받는 무선링크의 대역폭은 제한적인 물리적, 지역적 한계로 인해 점차 줄어들고 있으며 이것은 사용자의 처리율(Throughput)을 감소시키는 큰 요인으로 들 수 있다. 본 논문에서는 기존의 헤더압축방식인 RFC2507기법과 확장된 형태의 헤더압축 기술과 에러 감지시 신속하고 적절한 복구기술에 관하여 중점을 두고 있는 ROHC(RFC3095) 기법에 관하여 기술하였고, 특히 이 기법의 개선에 역점을 두었다. RTP헤더에 포함된 SN, TS의 압축효율과 견고성(Robust)을 향상시키는 확장된 ROHC(Extended ROHC) 알고리즘을 연구하였고, 그 알고리즘을 위한 확장 헤더의 표준을 제시하였으며, 개선된 알고리즘을 시뮬레이션을 통하여 증명하기 위해 비디오 패킷을 대상으로 실험하였다.

• 한국환경과학회지
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• 제5권5호
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• pp.593-603
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• 1996

용응탄산염 연료전지의 산소전극성능모사를 위한 이중기공구조의 filmed agglomerate model을 연구하였다. 이 모델에서는 전극과 전해질 계면의 물리, 화학적인 현상 및 전극반응기구를 고려하여 정상상태 에서 전극의 특성을 조업조건에 따라 표시할 수있다. 기존의 연구에서 기하학적인 구조를 가정하여 전극반응면적을 이론적으로 계산한 반면에 본 연구에서는 porosimeter를 이용한 기공도와 기공구조 분포 측정자료를 이용한 방법을 제시하였다. 계산결과는 전극재질, 기체조성, 전극두께, agglomerate 기공도 및 전해질 막의 두께에 따른 영향을 전류밀도와 과전압의 관계로 표시하였다. 또한 전극 재질로 perovskite (La0.8Sr0.2CoO3)와 NiO를 사용하여 실제전지를 이용한 성능을 측정하여 이론치와 비교하였다. 두전 극의 반쪽전지 실험에서 유사한 성능을 나타내었다. Perovskite 전극은 전극 기공도 65%, agglomerate 기공도 12% 그리고 전극두께 1.5~2mm에서 최적의 결과를 보여주었다. NiO전극의 경우 peroxide 반응기구에서 superoxide 반응기구의 계산결과보다 실험치와 일치하는 좋은 결과를 보였다.

• 대한간호학회지
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• 제31권5호
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• pp.921-931
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• 2001

The purpose of this study was to investigate the rate of pregnancy, abortion, delivery and contraceptive use and the relationship between the related factors and the early coitus among Korean teenagers. Method: The subjects of this study were 12,733 teenagers age 13-19 years in 7 major cities and 9 provinces in Korea. Data was collected from 2 Oct., to 28 Oct., 2000 and analyzed by using SPSS 10.0 Program. Results: The results showed pregnancy rate 4.5%, delivery rate 0.5%, abortion rate 0.4%. Adolescent girls who experienced coitus relatively went to vocational school, coeduaction school, night school in the general characteristics (p=0.000). Adolescent girls who experienced coitus tend to go to video room (18.5%), go the singing room (60.7%), the bar (54.8%), petting with the partner during the dates. There were overlapping juvenile delinquencies such as drinking (89.2%), pornography (65.3%), bond inhalation (2.7%), leaving homes (43.7%), smoking (14.5%), cyber sex (70.8%), phone sex (12.9%). Adolescent girls who experienced coitus were more suffering from Wangtta (26.1%) than who had not. They showed significant positive attitudes toward coitus; such as feeling of excitement (6.6%), nature (37.9%), beauty (8.7%). On the other hand, they had more guilty (2.8%) than the inexperienced (p=0.000). The main factors relating to early coitus were 'to confirm love' (46.9%), 'afraid of rejection' (32.2%). They think the benefits of coitus were 'more intimacy with boyfriends' (20.6%), 'satisfaction of curiosity' (16.8%). The losses on coitus were 'worry about pregnancy' (73.7%) and 'unability to refuse sexual contacts' (28.7%) Conclusion: It could be concluded that it is necessary to plan different sex education programs according to general characteristics and delinquency behaviors of teenage girls in Korea.

• 건축역사연구
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• 제15권5호
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• pp.19-39
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• 2006

This study deals with construction contract bid-rigging by Japanese contractors who monopolized the construction market of the Korean Peninsula during the Japanese colonial rule, and investigates the abuses of the contract bid-rigging. First of all, construction contract bid-rigging in Korea was triggered by Japanese construction contractors and contract brokers, who had savored the benefits of bidrigging in Japan and had repeated the bid-rigging in Korea since 1903. Second, the agency played a significant role to mediate construction contractors, and existed throughout the Japanese colonial rule on the Korean Peninsula with changing their names. Most of them were engaged in major contract bid-rigging scandals. Among them was Construction Association of Korea, which existed for over 13 years. The agencies had took part in governmental services since the mid-1930s when Japan exploited Korean people during wartime, and focused on sweating human resources for the constructions. Third, one of the biggest construction bid-rigging scandals during the Japanese colonial rule was "the 1st and 2nd scandal on Daegu construction contract bid-rigging." Indeed, the second scandal paved the way for the serial scandals: "Kyeongseong construction contract bid-rigging scandal", "Busan construction contract bid-rigging scandal", and other cases throughout the nation. Fourth, along with the contract bid-rigging cases related to the Japanese Government-General of Korea and local authorities, bid-riggings firmly took rooted in local governments' farmland reclamation projects in the 1920s and the poor relief services in the 1930s. The "bid-rigging charges" forced contractors to compensate their losses with exploiting material costs and labor costs, generating serious problems. The construction contract bid-rigging enabled Japan to monopolize the construction industry and to sweat farmers on the Korean Peninsula. Against this backdrop, contract bid-rigging by Japanese construction contractors during the its colonization made Korean contractors ruled out, and helped Japanese monopolize the industry. A large amount of bid-rigging charges drove Japanese contractors to do fraudulent work with cheap materials and to exploit Korean labor force.

• The Plant Pathology Journal
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• 제32권3호
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• pp.182-189
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• 2016

Together with the Fusarium graminearum species complex, F. culmorum is a major member of the causal agents of Fusarium head blight on cereals such as wheat, barley and corn. It causes significant yield and quality losses and results in the contamination of grain with mycotoxins that are harmful to humans and animals. In Korea, F. culmorum is listed as a quarantine fungal species since it has yet to be found in the country. In this paper, we report that two isolates (J1 and J2) of F. culmorum were collected from the air at a rice paddy field in Korea. Species identification was confirmed by phylogenetic analysis using multilocus sequence data derived from five genes encoding translation elongation factor, histone H3, phosphate permease, a reductase, and an ammonia ligase and by morphological comparison with reference strains. Both diagnostic PCR and chemical analysis confirmed that these F. culmorum isolates had the capacity to produce nivalenol, the trichothecene mycotoxin, in rice substrate. In addition, both isolates were pathogenic on wheat heads and corn stalks. This is the first report on the occurrence of F. culmorum in Korea.

• The Plant Pathology Journal
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• 제35권6호
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• pp.654-661
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• 2019

The soybean cyst nematode, Heterodera glycines, is a major plant-parasitic nematode that has caused important economic losses to Korea's soybean production. Four species of cyst nematodes, H. schachtii, H. glycines, H. trifolii, and H. sojae, all belong to schachtii group are coexist in field soil in Korea. The rapid identification of the nematode is crucial for preventing crop damage and in decision making for controlling this nematode. This study aimed to develop a species-specific primer set for quantitative PCR (qPCR) assay of H. glycines. The specific primer set (HGF1 and HGR1) for H. glycines was designed based on the cytochrome c oxidase subunit I (COI) sequence of mitochondrial DNA. After optimization, it is possible to identify the H. glycines using a qPCR assay with DNA extracted from a single cyst and single second-stage juvenile (J2). The specificity was confirmed by the absence of SYBR fluorescent signals of three other Heterodera species. A serial dilution of DNA extracted from a single cyst was obtained for the sensitivity test. The result showed that the standard curve of the test had a highly significant linearity between DNA concentration and Ct value (R² = 0.996, slope = -3.49) and that the detection limit concentration of DNA of the primer set was 10 pg of DNA per reaction. Our findings suggested that H. glycines could be distinguished from H. sojae and other Heterodera species when a qPCR assay is used with a specific primer set.

• Asian-Australasian Journal of Animal Sciences
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• 제13권3호
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• pp.401-412
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• 2000

Like other livestock, monogastric animals are essential components of the farming systems in the tropical countries. Pigs, chicken and ducks are by far the most important animals in the culture of the peoples of developing countries in the tropics. Traditionally these animals are raised in small farms and they are also the bulk producers of meat, eggs etc. in the tropics. In many countries the farmers of these small farms are unable to meet the requirement set by financial institution and other loan giving agencies for agricultural loan. Thus, the small farmers can get neither the opportunity to generate sufficient income to support the family nor to extend the livestock activities. The production systems are characterized by small number of animals with no or minimal inputs, low outputs and periodic destruction of animals by disease. Typically the litter size or flocks are small in number with each household containing 5-6 pigs and 7-10 poultry. Animals are owned by individual households and mostly maintained under a scavenging systems with little or no inputs for housing, feeding or health care. Because of the nature of this production system, productivity of these animals is rather low. The low level of inputs is due to a lack of capital and a low risk oriented outlook. The feed resource base for monogastric is scavenging and consists of household waste, roots and tuber, grain by-products and anything edible found in the immediate environment. Usually farmers select breeding gilts from their own female piglets or to a lesser extent, buy them from neighbors for natural mating. As regards poultry attempts have been made to increase egg and meat production by improving local poultry birds by upgrading and crossbreeding with exotic germ plasma in the tropics. Animal disease present a major constraint to animal production in the tropical region and the extent of the losses due to disease is very high.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.146-146
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• 2017

The pod shattering or dehiscence is essential for the propagation of pod-bearing plant species in the wild, but it causes significant yield losses during harvest of domesticated crop plants. Identifying novel molecular makers, which are linked to seed-shattering genes, is needed to employ the molecular marker-assisted selection for efficiently developing shattering-resistant soybean varieties. In this study, a genetic linkage map was constructed using 115 recombinant inbred lines (RILs) developed from crosses between the pod shattering susceptible variety, Keunol, and resistant variety, Sinpaldal. A 180 K Axiom(R) SoyaSNPs data and pod shattering data from two environments in 2001 and 2015 were used to identify quantitative trait loci (QTL) for pod shattering. A major QTL was identified between two flanking single nucleotide polymorphism (SNP) markers, AX-90320801 and AX-90306327 on chromosome 16 with 1.3 cM interval, 857 kb of physical range. In sequence, genotype distribution analysis was conducted using extreme phenotype RILs. This could narrow down the QTL down to 153 kb on the physical map and was designated as qPDH1-KS with 6 annotated gene models. All exons within qPDH1-KS were sequenced and the 6 polymorphic SNPs affecting the amino acid sequence were identified. To develop universally available molecular markers, 38 Korean soybean cultivars were investigated by the association study using the 6 identified SNPs. Only two SNPswere strongly associated with the pod shattering. These two identified SNPs will help to identify the pod shattering responsible gene and to develop pod shattering-resistant soybean plants using marker-assisted selection.

• 한국임상수의학회지
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• 제22권4호
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• pp.365-370
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• 2005

Enzootic pneumonia caused by Mycoplasma hyopneumoniae is responsible for major economic losses in pig herds of world wide. Mycoplasma hyopneumoniae can also act as a primary pathogen of porcine respiratory disease complex followed by bacterial or viral infection. This study was carried out to investigate the prevalence of mycoplasmal pneumonia of slaughtered pigs in Jeju for two years. The lungs and sera of 214 cases were examined for gross and microscopic lesions of the lungs, immunohistichemistry test for Mycoplasma hyopneumoniae antigen and enzyme-linked immunohistichemistry assay (ELISA) for serum antibody titer. Pulmonary consolidation was observed in the lungs of 163 pigs $(76.1\%)$ with average gross lesion score of $6.0\%$., Bronchointerstitial pneumonia was most frequently observed $(78.5\%)$. The incidence of pulmonary consolidation was decreased in vaccinated pigs compared to that of non-vaccinated pigs. The rate of consolidation in the lungs was significantly decreased in the vaccinated pigs (P<0.05). Antigen of Mycoplasma hyopneumoniae was identified by immunohistichemistry test in the lungs of 174 pigs $(81.3\%)$. ELISh antibodies to Mycoplasma hyopneumoniae were detected in 154 pigs $(72.0\%)$. These results showed the prevalence of swine pneumonia and the incidence of Mycoplasma hyopneumoniae in slaughtered pigs of Jeiu province. We expect that these results would be helpful for the control of swine mycoplasmal pneumonia and porcine respiratory disease complex in Jeju.