• 한국토양비료학회지
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• 제36권6호
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• pp.429-436
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• 2003

파종심도차이에 의한 콩의 하배축 생장동안 hook 열림 정도와 sucrose 대사의 변화를 관찰하기 위하여 황금콩을 2.5, 5.0, 7.5 및 10.0 cm의 깊이로 파종하였다. hook 열림 정도는 파종심도가 깊을수록 늦어진다는 사실이 밝혀졌다. 또한 열림각도는 하배축생장과 1% 수준에서 고도의 부(-)의 상관을 나타냈다. 또한 파종심도는 하배축 생장과 고도의 정(+)의 상관관계가 있었으며 이는 파종심도가 깊을수록 하배축생장이 촉진된다는 것을 의미하였 다. 더 나아가 하배축에서의 fructose와 glucose 함량이 자엽보다 다량 존재한다는 사실이 밝혀졌다. 하배축에서 fructose와 glucose는 지상부 출현 직전에 가장 높았으며 출현 후 급격히 감소하는 경향이었다. 총 가용 당의 함량은 파종심도가 얄은 2.5 cm와 5.0 cm로 파종한 콩 종자에서는 출현 후 까지 지속적으로 유지되는 반면 파종심도가 깊은 종자에서는 현저히 낮았다. 이러한 결과는 파종심도가 갚은 종자에서 하배축의 과도한 생장동안 세포벽 등의 생성을 위해 당이 모두 소진되었기 때문이었다. 이런 현상은 hook 열림이 출현 후 광 signal과 밀접한 관계가 있음을 말해 주는 것이었다. 깊은 파종심도에서 hook 열림의 지연은 하배축 생장이 암상태에서 진행되기 때문이었다. 이는 정단부 hook 열림 현상이 광과 관계한 sucrose 분해대사와 함께 진행한다는 것을 의미하였다.

• 수산해양기술연구
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• 제53권3호
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• pp.219-227
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• 2017

In pelagic longline, deploying the gear such that the depth of the hook is the same as that of the target fish is important to improve the fishing performance and selectivity. In this study, the depth of the tuna longline hook was estimated using the mass-spring model, catenary curve method, and secretariat of the pacific commission Pythagorean method in order to improve the performance of the longline gear in Fiji. The former two methods were estimated to be relatively accurate, and the latter showed a large error. Further, the mass-spring model accounted for the influence of tidal current in the ocean, which was found to be appropriate for use in field trials.

• 수산해양기술연구
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• 제39권4호
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• pp.305-317
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• 2003

중층 연승어구의 수중형상과 낚시의 심도는 어획성능을 좌우하는 중요한 요소하다. 또한 매조업시마다 얻어지는 낚시별 어획어종, 크기등과 같은 조획 데이터의 체계적인 관리와 분석도 향후 조업을 위한 지표로서 고려되어야 한다. 본 연구에서는 유향$.$유속에 따른 어구의 수중 형상을 시뮬레이션하여 해석하였고, 해석의 정확성을 검증하기 위해서 모형실험을 실시하였다. 또한 시뮬레이션에서 얻어진 각 낚시별 심도 정보를 활용하여, 낚시별로 사용한 미끼와 어획된 어종의 자료를 처리할 수 있는 데이터베이스 시스템을 구축하였다. 본 연구에서 얻어진 결과를 요약하면 디음과 같다. 1. 영각과 단축률이 일정할 때, 유속이 증가함에 따라 낚시의 심도는 유속에 비례해서 감소하였다. 2. 단축률과 유속이 일정할 때, 영각이 증가함에 따라 낚시의 심도는 영각에 비례해서 감소하였다. 3. 영각과 유속이 일정할 때, 단축률이 증가함에 따라 낚시의 심도는 단축률에 비례해서 감소하였다. 4 시뮬레이션에 의한 수중 형상과 모형어구의 수중 형상을 비교한 결과, 오차는 $ {\pm}3%$ 이내로 나타나 실험결과에 대한 시뮬레이션의 결과가 잘 일치함을 나타내었다. 5 본 연구에서 시뮬레이션에서 얻어진 낚시 심도정보를 활용한 조획률 데이터베이스 시스템은 여러 파라미터들 예를 들어 미끼, 낚시 섬도 등에 따라서 어획어의 종류와 크기를 분석할 수 있어서, 현장의 조획 데이터의 관리 및 분석에 많은 도움을 줄 수 있을 것이다.

• 수산해양기술연구
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• 제47권4호
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• pp.344-355
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• 2011

We conducted experiments to compare the catch rate of bigeye tuna and yellowfin tuna between circle hooks and straight shank hook in the Korean tuna longline fishery at the eastern and central Pacific Ocean from 2005 to 2007. We analyzed difference of fork length, survival and hooking location between a circle hook and a straight shank hook for both tunas, respectively. There was no difference in the mean fork length size of yellowfin tuna caught on the two type of hook but bigeye tuna was significant. In case of survival, there was no difference between two hook type, but the difference of hooking location was significant for both species. We also analyzed to find determinants of both tunas catch rate using generalized linear models (GLMs) which were used latitude, longitude, year, month, depth, hook type, bait type and so on as independent variables. Spatial factors, latitude and longitude, and temporal factors, year and month, affected catch rate of bigeye tuna and yellowfin tuna. And also, depth such as a marine environment factor was influenced on catch rate.

• 한국주조공학회지
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• 제23권5호
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• pp.257-267
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• 2003

In early solidification during the continuous casting of steel slabs, the formation of oscillation marks on the surface of slabs was mainly affected by carbon contents and casting conditions. The control of oscillation mark is required for the HCR(Hot Charged Rolling) process because the deep oscillation marks seriously deteriorate the surface qualities of steel slabs. The metallographic study has revealed that the oscillation mark can be classified principally according to the presence or absence of a small 'subsurface hook' and the depth of the oscillation marks in the subsurface structure at the basis of individual oscillation marks. The subsurface hook of oscillation marks was either straight or curved. When the amount of overflow was small and the subsurface hook was formed in the top of oscillation marks, the subsurface hook was straight and the oscillation mark was shallow. The oscillation marks without subsurface hook have small early solidification shell and were formed wide. The actual negative strip time$(t_N)$ was changed by the effect of meniscus level fluctuation Therefore irregular early solidification shell and oscillation mark were formed.

• Ocean and Polar Research
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• 제41권1호
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• pp.19-34
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• 2019

The present study obtained universal mathematical models of all elements and characteristics regarding hook and line fishing systems. To describe the hook and line fishing systems on site we used three kinds of coordinate systems: the earth based coordinate system, natural coordinate system, and flow (velocity) coordinate system. Mathematical models presented in this article allow us to define the shape of the fishing gear, the tension of the rope at different points, hydrodynamic resistance, diameter of the hook's wire, immersion depth of the fishing hooks, distance from hooks to the ground and the required lifting force of the floats. These models allow for the performance of computer simulations regarding any kinds of hook and line gears in still water or water where flow occurs.

• 한국어류학회지
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• 제20권2호
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• pp.105-111
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• 2008

다랑어낚시 및 사용미끼에 따른 어획률을 비교하기 위해, 2006년 9~10월간 태평양 중동부 해역에서 다랑어연승 시험조사가 수행되었다. 일반선형모형(GLM)을 이용하여 재래식 다랑어낚시 1종(J4)와 환형낚시 3종(C15, C16, C18), 미끼 5종(고등어(CM), 전갱이(JM), 밀크피쉬(MF), 정어리(SD), 오징어(SQ)) 및 낚시심도를 나타내는 낚시 순번들이 눈다랑어 어획률(1,000낚시당 마리수)에 미치는 효과를 평가하였다. 총 28회 조업에서 낚시순번 간 눈다랑어 어획률에는 유의한 차이가 인정되었다. GLM분석에서 낚시순번에 의한 눈다랑어 어획률 편차는 33%로 나타났다. 미끼 종류 간 어획률 차이는 그 편차가 2.7%로 적게 나타났고, 낚시형 4종 간 그 차이는 매우 적어 유의하지 않게 나타났다. 따라서, 낚시형 및 미끼 종류의 선택은 다랑어 연승어업에서 눈다랑어 어획률 차이에 영향을 주지 않는 것으로 평가되었으나, 어획수심을 나타내는 낚시순번은 눈다랑어 어획률에 영향을 주는 요인으로 판단되었다.

• Structural Engineering and Mechanics
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• 제91권3호
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• pp.263-277
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• 2024

The primary aim of this study is to introduce an innovative configuration for stirrup hooks in reinforced concrete beams and analyze the impact of factors such as stirrup spacing, placement, and hook lengths on the structural performance of reinforced concrete beam elements. A total of 18 specimens were produced and subjected to reversed cyclic loading, with two specimens serving as reference specimens and the remaining 16 specimens utilizing a specifically developed stirrup hook configuration. The experiment used reinforced concrete beams scaled down to half their original size. These beams were built with a shear span-to-depth ratio of 3 (a/d=3). The experimental samples were divided into two distinct groups. The first group comprises nine test specimens that consider the contribution of concrete to shear strength, while the second group consists of nine test specimens that do not consider this contribution. The preparation of reference beam specimens for both groups involved the utilization of standard hooks. The stirrup hooks in the test specimens are configured with a 90-degree angle positioned at the midpoint of the bottom section of the beam. The criteria considered in this study included the distance between hooks, hook angle, stirrup spacing, hook orientation, and hook length. In the experimental group examining the contribution of concrete on shear strength, it was noted that the stirrup hooks of both the R1 reference specimen and specific test specimens displayed indications of opening. However, when the contribution of concrete on shear strength was not considered, it was observed that none of the stirrup hooks proposed in the R0 reference specimen and test specimens showed any indications of opening. Neglecting the contribution of concrete in the assessment of shear strength yielded more favorable outcomes regarding structural robustness. The study found that the strength values obtained using the suggested alternative stirrup hook were similar to those of the reference specimens. Furthermore, all the test specimens successfully achieved the desired strengths.

• 수산해양기술연구
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• 제53권2호
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• pp.126-131
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• 2017

To improve the efficiency of hairtail trolling, it is important to gain an accurate understanding of the distribution of fish based on their diurnal vertical migration patterns. This study evaluated the vertical distribution of hairtails through catch efficiency tests using vertical longlines. Five replicate tests of the efficiency were carried out on the eastern coast of Jeju Island from August to September 2016, from 11:00 AM to 03:00 PM in the daytime and 11:00 PM to 03:00 AM in the nighttime. The fishing gear was composed of 20 hooks per line set, numbered in order from the first hook near the surface to the last hook on the seabed. The depth of the first hook was 18 m, and that of the last hook was 86 m. Pacific saury was used as the baits. In total, 10 sets of fishing gear were used per trip. After fishing, we counted the hairtails at each numbered hook, which were summed up both by number and in aggregate. A total of 232 hairtails were caught using 2,000 hooks: 193 individuals at daytime and 39 at nighttime. The hook rate was 11.5% : 9.6% at daytime; 2.0% at nighttime. For both daytime and nighttime catches, there were variations in the hook rates at each numbered hook. In the daytime, a maximum of 28.5% catches occurred at hook number 18, followed by 21.4% at number 20, and 10.7% at number 17, accounting for 60.6% of the daytime hook rates. In the nighttime, a maximum of 23.0% catches occurred at hook number 1, followed by 15.3% at hook number 4 and 9, accounting for 53.6% of the nighttime hook rate. Based on the above results, hairtails are usually distributed in deeper region in daytime, whereas they occur near the surface in nighttime. Therefore, it is necessary to position trolling lines according to diurnal vertical distribution layers of hairtails for fishing efficiency.

• 수산해양기술연구
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• 제47권3호
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• pp.173-182
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• 2011

The purpose of this paper is to provide useful information for fishermen in the manner of investigation a sinking speed of current type tuna longline gear at the North Pacific Ocean as a new developed tuna longline fishing ground. The sinking depth of mainline in connection with different basket was investigated. The experiments were also performed with different materials such as Supermansen (i.e., PE) and Hitech (i.e., PA) for the mainline to investigate the sinking depth of mainline and hooks. Furthermore, the relation between the sinking depth of hooks and catches are investigated also. The sinking depth of mainline at the first and the last shooting basket shows deeper than that of middle part of a basket due to reduced shortening ratio. The sinking depth of mainline and hook with Hitech material shows more shallow than that of Supermanse material, even the Hitech case was designed to sink deeper than that of Supermanse case. The highest catches arise at the middle part basket as the hook number 7 with around 248m sinking depth. From the results, longline with Hitech material is needed to increase the sinking force for reaching the relevant sinking depth. Moreover, the current strength at the North Pacific Ocean will be considered for further commercial fishing.