• 한국해양공학회지
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• 제27권6호
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• pp.22-26
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• 2013

The purpose of this study was to improve the design of a mooring line by attaching a lumped mass to it on the seabed. A numerical analysis of the redesigned mooring system is performed to analyze the effect of the weight of the attached lumped mass using the commercial software Orcaflex. The ultimate tension of the mooring system with the lumped mass is compared with that of a bare mooring line in the original design. An appropriately designed weight for the lumped mass is found to induce a critical lifted point in the mooring line by floater motion in the ultimate condition to move toward the floater position from the anchor point, while maintaining a similar safety factor for the mooring line. On the other hand, it is shown that excess weight for the lumped mass induces snapping in a mooring line, resulting in low safety factor for the mooring system. The distance between lumped weights is shown to be a minor parameter affecting the safety of a mooring line, although a shorter line has an advantage from an economic point of view. Using the optimal weight for the lumped mass attached to the mooring line on a seabed reduces the mooring line length and installation area occupied by a mooring system under real sea conditions.

• 반도체디스플레이기술학회지
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• 제12권1호
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• pp.15-21
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• 2013

In this paper, sensor system and inspection algorithm in order to inspect steel balance weight for automobile is described. Steel balance weight is composed of clip and weight, which is joined by press process. The defective one has a gap between clip and weight. To detect whether there is a gap, sensor system is simply configured with laser line projector and USB camera, which make it possible to measure the height difference of clip and weight area. Laser line pattern which is made on the surface of a balance weight is captured by USB camera. In case that USB camera is used in machine vision, barrel distortion caused by wide angle lens makes the captured image distorted. Image warping function is applied to correct the distortion. Simple image processing algorithm is applied to extract the laser line information and whether it is good or not is judged through the extracted information.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.36-36
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• 2003

In the present study, growth performances of the offspring from selected brood line were compared to those of the offspring from non-selected brood line of red sea bream. Offspring groups were mass produced separately from two brood lines, selected and non-selected Korean strain. Selected brood line have been selected by fish size for four generations (upper 5∼30% per generation) and non-selected brood line is the second generation of wild population at south sea in Korea. There's no significant difference in body length between offspring from selected and non-selected brood line during early growing stage (until 96-days old). However, offspring from selected brood line had superior body weight growth than offspring from non-selected brood line. At sea cages rearing trials with communal stocking, Offspring from selected brood line showed significantly better performance in body weight, body length, weight gain, specific growth rate and feed consumption (but not in feed conversion ratio) than offspring from non-selected brood line. At 24 months old, offspring from selected brood line grew faster 1.10 times in body length and 1.41 times in body weight than offspring from non selected brood line. The response to selection when compared to a non-selected line is on average of 10% in weight per generation at 24 months old.

• Plant Resources
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• 제5권1호
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• pp.45-50
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• 2002

Korean cultivars of buckwheat(Fagopyrum esculentum Moench.) was crossed with Canadian cultivars in order to improve seed yield as well as leaf production of buckwheat for using as food and medicine. The agronomic characteristics and rutin contents of F$_2$ hybrids are investigated for further selection of superior lines. Dry weight per plant was the highest in a line 1110(6.71g) and leaf weight per plant was the highest in a line 1110(1.91g). Hybrid seeds were 0.55 - 0.70cm long and 0.37 - 0.47cm wide on average. 100 seeds weight ranged from 2.57g to 3.58g. Line 1076 produced the longest seeds(0.70cm) and line 1186 was the longest in seed width. Line 1196 showed the highest 100 seeds weight(3.58g). The highest frequency of the LWR(length/width rate) was 0.66~0.70, indicating that seed shape of the hybrids was mostly oval. Line 1087 showed the highest contents of rutin(77.26ppm). Lines 1090 and 1181 contained respectively rutin of 54.76ppm and 54.35ppm in the seeds. From the yield and rutin point of view, the most superior lines was line 1087 among the lines used for this study.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.639-648
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• 2005

Up to now, practical engineers applying simplicity value of rockfall block weight suggested in design manual without considering in-situ rockfall block weight which reflect joint characteristics. However, the size of rockfall block varies with joint spacing of discontinuities and influences over rockfall analysis results. In this paper, we estimate realistic rockfall block weight distribution using statistical invariances of joint spacing derived from scan-line survey result. And, we study whether this distribution is applicable in practical rockfall analysis directly. As the results of this study, rockfall analysis results that using rockfall block weight distribution estimated from scan-line survey show resonable and realistic outcomes.

• Asian-Australasian Journal of Animal Sciences
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• 제23권3호
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• pp.302-307
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• 2010

The present study aimed to investigate the effects of maternal factors on body weight at hatching (day-old) and at six weeks of age in a commercial broiler line. A total of 6,765 records on body weight at day-old (BWTDO) and 115,421 records on body weight at six weeks of age (BWT6W), originated from a commercial broiler line during 14 generations, were used to estimate genetic parameters related to the effects of maternal traits on body weight of chicks immediately after hatch or six weeks thereafter. The data were analyzed using restricted maximum likelihood procedure (REML) and an animal model with DFREML software. Direct heritability ($h^{2}{_a}$), maternal heritability ($h^{2}{_m}$), and maternal environmental variance as the proportions of phenotypic variance ($c^{2}$) for body weight at day-old were estimated to be 0.050, 0.351, and 0.173, respectively. The respective estimated values for body weight at six weeks of age were 0.340, 0.022, and 0.030. The correlation coefficient between direct and maternal genetic effects for six-week-old body weight was found to be -0.335. Covariance components and genetic correlations were estimated using a bivariate analysis based on the best model determined by a univariate analysis. Between weights at hatching and at six week-old, the values of -0.07, 0.53 and 0.47 were found for the direct additive genetic variance, maternal additive genetic variance and permanent maternal environmental variance, respectively. The estimated correlation between direct additive genetic effect influencing weight at hatch and direct additive maternal effect affecting weight at six weeks of age was -0.21, whereas the correlation value of 0.15 was estimated between direct additive maternal effect influencing weight at hatch and direct additive genetic effect affecting weight at six-week-old. From the present findings, it can be concluded that the maternal additive genetic effect observed for weight at six weeks of age might be a factor transferred from genes influencing weight at hatch to weight at six-week-old.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.335-335
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• 2017

Recently NERICA (New Rice for Africa) was developed by a crossing of African rice (Oryza glaberrima Steud.) and Asian rice (Oryza sativa L.) in West Africa, and is considered to be drought resistant, but drought resistance of NERICA and differences between Asian rice are not clarified enough. In this research, NERICA (four cultivars and two lines), Asian rice (three cultivars and sativa parent of NERICA) and African rice (glaberrima parent of NERICA) were cultivated in the field in Shizuoka University under drought and traits of each cultivar and line relevant to drought resistance, stomatal conductance by porometer, soil water content of individual depths by TDR method, SPAD values by SPAD meter and leaf thickness by micrometer, were measured and compared with dry matter production and yield. Effects of compost were also compared among sativa parent, one NERICA cultivar and two NERICA lines. Glaberrima parent showed highest top dry weight. One NERICA line, one drought resistant Asian rice cultivar and sativa parent, showed higher top dry weight and yield (ear weight) than other Asian rice cultivars and NERICA cultivars and line tested. Compost tended to increase top dry weight and yield in one of NERICA line and sativa parent. But in one NERICA cultivar and line, top dry weight and yield were not increased. In one of Asian rice, one of NERICA line and sativa parent that showed high top dry weight and yield, stomatal conductance was high. On the contrary the glaberrima parent and in other NERICA cultivars and line it was low. In sativa parent compost increased stomatal conductance but in NERICA cultivar and lines it was not. Among cultivars and lines that showed high top dry weight and yield sativa parent and one of NERICA line SPAD value and leaf thickness were high but in one of Asian rice and glaberrima parent they were low. Cultivar and line differences in yield and top dry weight among Asian rice and NERICA were significantly correlated with those in stomatal conductance ($r=0.778^{**}$ and $r=0.654^*$, respectively) and those in leaf thickness ($r=0.600^*$ and $r=0.640^*$, respectively). In Asian rice cultivars average soil water content was significantly correlated with yield ($r=0.886^*$) but in NERICA cultivars and lines it was not significant correlated (r= -0.256). Cultivar and line differences in leaf thickness were significantly correlated with SPAD value ($r=0.773^{**}$). In Asian rice cultivars it was significantly correlated ($r=0.962^{**}$), but in NERICA cultivars and lines it was not significantly correlated (r=0.559). Asian rice cultivars tended to consume soil water to increase yield but in NERICA cultivars and lines the tendency was not clear. Correlation between SPAD value and leaf thickness was different between Asian rice and NERICA cultivars and lines, and in Asian rice cultivars it was significantly correlated but in NERICA cultivars and lines it was not significant. Importance of maintaining high stomatal conductance by high leaf thickness was clarified.

• 한국의류학회지
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• 제28권3_4호
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• pp.396-402
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• 2004

The purpose of this study was to investigate the difference of cotton fabric texture perceived between on-line(screening fabric) and off-line(real fabric), and to analyze fabric characteristics having an effect on the difference. The similarity of 55 various cotton fabrics perceived between on-line and on-line were measured showing simultaneously real fabrics and screening fabrics by 7-scale questionnaire. And the characteristics of cotton fabrics such as weave structure, thickness, weight, fabric density, stiffness, Hunter's L, a, b, and hue were measured. Cotton fabrics were classified into 3 groups by extent of similarity. There were no significant differences in weft density, stiffness, Hunter's L, a, b, and hue among 3 groups. But there were significant differences in weave structure, thickness, weight, warp density, and difference of warp ＆ weft density. The fabrics having large similarity were thick and heavy, had small warp density and difference of warp ＆ weft density, and distinct surface texture. The group having medium similarity included fabrics of medium thickness and weight, having weak surface texture, large warp density and difference of warp ＆ weft density. The group having small similarity, which the differences between on-line and off-line were large, included thin and light fabrics having smooth surface and large warp density and difference of warp ＆ weft density.

• 한국가금학회지
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• 제10권2호
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• pp.75-81
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• 1983

산란종계의 란중을 개량하기 위하여 란중에 대한 유전력과 유전상관등의 유전적 모수를 추정한 후 백색 레그혼종 2계통(A, K)에서 주령에 따른 란중의 증가양상을 살펴보았다 또한 선발에 의한 유전적 개량량을 크게 하기 위하여 조기선발을 실시할 경우 조기선발의 최적시기를 찾아내는 것이 중요하므로 년 평균란중에 대한 각 기간별 란중의 상관관계와 아울러 회귀관계를 분석하여 최적 선발시기를 알아보았고 각 기간별 선발에 의한 개량량을 상대적으로 나타내므로써 조기선발에 대한 타당성을 구명하고자 본 시험을 수행하였으며 얻어진 결과는 다음과 같다. 주령이 늘어남에 따라 란중도 증가하였는데 산란초기에서는 증가량이 컸지만 점차 감소하였으며 회귀방정식으로 나타낸 증가량은 A, K계통에서 주당 각각 0.46g과 0.83g이었다. 년 평균 란중에 대한 각 기간별 란중의 회귀계수는 29-32주령의 평균란중이 0.86(A), 0.88(K)로 나타나 가장 큰 수치를 보였다. 45-48주령의 평균란중을 기준으로 했을 때의 선발에 대한 각 기간 평균란중의 선발상대효율에서는 A계통에서 33-36주령, K통계에서 29-32주령의 추정치가 가장 크게 나타나서 이 시기에서의 조기선발에, 대한 타당성을 보여주었다.

• 한국기계가공학회지
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• 제20권8호
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• pp.86-92
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• 2021

As interest and demand for high value-added industries, including the global automobile and aerospace industries, have increased recently, demand for line centers with excellent performance that can respond to the production system for producing high value-added products is also rapidly increasing. A line center improves productivity based on the installed area using a multi-spindle compared to a conventional machining center. However, as the number of spindles increases, the weight increases and results in structural problems owing to the heat and vibration generated by each spindle. Therefore, it is necessary to improve machining precision through the structural improvement of the line center. This study presents research on the stabilization design of the line center through structural stability analysis through structural analysis to develop a compact multi-axis line center. An optimization model of the line center has been proposed to improve the processing precision and increase the rigidity by performing weight reduction based on the structural analysis results.