• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.117-123
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• 2001

Anchovy scoop nets, a kind of lift net have been used in the coastal area of Cheju and South sea of Korea. An incandescent lamp(AC 100V, 1kW) is being used as a fishing lamp for gathering anchovy. Fishing lamp was installed at 1m ahead of the prow and 1.5m higher than the water surface. The fishing lamp let fish school rise to the water surface and attract to bag net. Accordingly, a successful anchovy catching depends on controling of fishing lamp. On the study, the distribution of spectral irradiance illumination of incandescent lamp(1kw) and the irradiance efficiency of reflection plate were analyzed and discussed to investigate the ability of fishing lamp which can attract anchovy school effectively. The results obtained are summarized as follows : 1. Around 180% of irradiance efficiency of incandescent lamp was increased by using the reflection plate. The light of lamp was radiated into water with circular shape. 2. The irradiance illumination of incandescent lamp in air was a maximum in wave length of 994nm but it was 690nm at 0.5m and 1.0m of water depth. 3. The relationship between water depth(x) and water illumination(y) of vertical light is represented as follows : y=146.03e supper(-0.37x) 4. The light of incandescent lamp(1kW) pass through much better into vertical direction than horizontal but it was estimated that the light was not able to reach depth of 20m.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.37-47
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• 2009

This study develops a technique training program to enhance the completion of Kolman, the high air flight technique, and applies it to two national athletes of the horizontal bar, one of the gymnastic events, for eight weeks. After that, their improvement was measured through 3D motion analysis to help them elevate their performance. The training program includes swing, hand release, twist, and bar hold, and its implementation produced the results stated below. They were made to practice the motion in the following way. After the hand-standing of giant swing which initiates the motion, they lift their body upward a little bit more. Next, they take their body down almost like a vertical descent and make a deep tap swing. Instead of doing the tap swing which widens the flection of hip and shoulder joints, while body revolution is more emphasized in particular, they release the bar as raising the centroid of their body sufficiently. During the flight, they try to narrow every joint in their body. As a result, the bar's elasticity becomes greatly increased, and since the backing rate of their body gets higher, the centripetal force of the swing is improved that they can release the bar in the higher position. In addition, because they can erect their body faster during the flight, they can perform comfortable twist and revolution in the air. They can also adjust the direction of the flight easily without too much concern for the proper timing of hand release as they rise. Thereby, they can not only maintain adequate distance from the bar for the bar hold but also ensure enough distance for body revolution and twist.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.63-70
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• 2015

This paper proposes a novel airfoil named "KA2" for the blade of the wind turbine systems. Dynamic loads characteristics are analyzed and compared using aerodynamic data of ten airfoils including the proposed airfoil. The blade is divided into the sixteen elements in the longitudinal direction of the blade for applying the Blade Element Method Theory (BEMT) method, and in each element, torque, thrust, and pitching moment are calculated using turbulent time varying wind speed and aerodynamic data of each wing. Additionally, each force and torque is accumulated in the whole region of the blade for the estimation of representative values. The magnitude of such forces is comparatively analyzed for different airfoils. The angle of attack is constant below the rated wind speed due to the fact that the tip speed ratio is kept at the constant value, and it increases in the region of over rated wind speed as the tip speed ratio decreasing with constant rated rpm and increasing wind speed. Such increase in the angle of attack causes the changes of the force acting on the airfoil with different characteristics of lift and drag in the stall region of each different airfoil. Even though the mean wind speed is in the rated speed in a given time, because of the turbulence, it has either the over rated or under rated speed most of the time. Furthermore, the dynamic properties of each force are analyzed in this rated wind speed in order to objectively understand the dynamic properties of the blades which are designed based on the different airfoils. These dynamic properties are also compared by the standard deviation of time varying characteristics. Moreover, the output characteristics of the wind turbine are investigated with different airfoils and wind speeds. Based on these investigations, it was revealed that the proposed airfoil (KA2) is well applicable to the blade with passive pitch control system.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.835-845
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• 2013

Association rule of data mining techniques is the method to quantify the relevance between a set of items in a big database, andhas been applied in various fields like manufacturing industry, shopping mall, healthcare, insurance, and education. Philosophers of science have proposed interestingness measures for various kinds of patterns, analyzed their theoretical properties, evaluated them empirically, and suggested strategies to select appropriate measures for particular domains and requirements. Such interestingness measures are divided into objective, subjective, and semantic measures. Objective measures are based on data used in the discovery process and are typically motivated by statistical considerations. Subjective measures take into account not only the data but also the knowledge and interests of users who examine the pattern, while semantic measures additionally take into account utility and actionability. In a very different context, researchers have devoted a lot of attention to measures of confirmation or evidential support. The focus in this paper was on asymmetric confirmation measures, and we compared confirmation measures with basic association thresholds using some simulation data. As the result, we could distinguish the direction of association rule by confirmation measures, and interpret degree of association operationally by them. Futhermore, the result showed that the measure by Rips and that by Kemeny and Oppenheim were better than other confirmation measures.

• Journal of the Korean Data and Information Science Society
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• v.25 no.3
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• pp.601-609
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• 2014

The most widely used data mining technique for big data analysis is to generate meaningful association rules. This method has been used to find the relationship between set of items based on the association criteria such as support, confidence, lift, etc. Among them, confidence is the most frequently used, but it has the drawback that we can not know the direction of association by it. The attributably pure confidence was developed to compensate for this drawback, but the value was changed by the position of two item sets. In this paper, we propose four symmetrically and attributably pure confidence measures to compensate the shortcomings of confidence and the attributably pure confidence. And then we prove three conditions of interestingness measure by Piatetsky-Shapiro, and comparative studies with confidence, attributably pure confidence, and four symmetrically and attributably pure confidence measures are shown by numerical examples. The results show that the symmetrically and attributably pure confidence measures are better than confidence and the attributably pure confidence. Also the measure NSAPis found to be the best among these four symmetrically and attributably pure confidence measures.

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.63-87
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• 2002

The purpose of this study was to analyze the kinematic variables when Uchi-mata(inner thigh reaping throw) performing by Kumi-kata(engagement position, basic hold) types A, B(A: grasping part-behind neck lapel, B: chest lapel) in Judo with three dimensional analysis technique DLT method by videography. The subjects were four male judokas who have been training in Yong-In University(YIU), on Korean Representative level and Uchi-mata is their tokui-nage(favorite technique), the throwing form was filmed on two S-VHS 16mm video camera( 30frame/sec. Panasonic). Kinematic variables were temporal, posture, and COG. The data collection was performing by Uchi-mata. Six good trials were collected for each condition (type A, B) among over 10 trials. The mean values and the standard deviation for each variable were obtained and used as basic factors for examining characteristics of Uchi-mata by Kumi-kata types. The results of this analysis were as follows : 1) Temporal variables The total time elapsed(TE) by Uchi-mata of types A, B were 1.45, 1.56 sec. respectively. Types A shorter than B. 2) Posture variables In performing of Uchi-mata, the range of flexion in type A, left elbow was $45^{\circ}$ and B was $89^{\circ}$ from Event 2(E2) to Event 6(E6). Type A and B were quite different in right elbow angle in Event1(E1). Left shoulder angle of type A was extended and type B was flexed in E4. Both types right shoulder angles were showed similar pattern. Also both hip angles(right/left) were showed similar pattern. When type A performed Uchi-mata the knee-angle of supporting foot showed $142^{\circ}$in the 1st stage of kake phase[KP], and extended to $147^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $86^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $126^{\circ}$in the 1st stage of KP, and extended to $132^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $106^{\circ}$in the 1st stage of KP, and extended to $121^{\circ}$in the 2nd stage of KP. When type B performed Uchi-mata the knee-angle of supporting foot showed $144^{\circ}$in the 1st stage of KP, and extended to $154^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $92^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $132^{\circ}$in the 1st stage of KP, and extended to $140^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $103^{\circ}$in the 1st stage of KP, and extended to $115^{\circ}$in the 2nd stage of KP. During Uchi-mata performing, type A showed pulling pattern and type B showed lift-pulling pattern. As Kumi-kata types, it were different to upper body(elbow, shoulder angle), but mostly similar to lower body(hip, knee, ankle angle) on both types. 3) C. O. G. variables When the subjects performed Uchi-mata, COG of type A, B up and down in vertical aspect was 71cm, 73.8cm in height from the foot in the 2nd stage of KP. As Kumi-kata types, it were different on medial-lateral direction aspect but weren't different in Kuzushi phase on vertical direction aspect.

• Archives of design research
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• v.19 no.1 s.63
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• pp.293-302
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• 2006

clay cups with handles made in studios in Korea and the United States were selected and analyzed. The shape of cup were fixed to ensure proper comparison between handle size of the cup and position. The variable factors were the thickness of the handle, the number of fingers required to hold the cup, the relationship between the handle's shape and the position of its attachment to the cup, the effect of the handle's setter, the change in shape of the handle's thickness, and the relationship between the cup's weight center and handle. Preference test were designed and tested to the users, and the results were analyzed. The results showed that to make a comfortable handle, it is important to incorporate the shape of the resting hand in the design of the handle. Specifically, the design should be such that the cup can be held comfortably. This is possible if the weight of the cup is spread evenly when several fingers are inside the handle's curve and if such factors as the hand size, the curve of the fingers, and the position that best controls the cup's weight center are carefully considered. At this time, if there is a setter for the thumb, a cup of the same weight can be lifted more lightly. In the design of such a cup, the oval line is drawn by extending the cup's handle toward the direction of the cup's body. If the cup's weight center is located on the oval line, the cup's handle may be said to be effective. In such a case, the nearer the handle is to the cup's body weight center, the less power is needed to lift the cup efficiently. Our test results can be applied as a powerful tools in design and manufacturing cups with handle in terms of artistry and functionality.