• 융합신호처리학회논문지
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• 제4권3호
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• pp.21-26
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• 2003

본 논문은 퓨리에 변환을 이용한 3차원 폐곡면 객체의 특징 벡터 추출 기법을 제시한다. 특징 벡터는 3차원극좌표계를 이용하여 폐곡면 객체의 회전각도별 내측거리값을 퓨리에 변환을 통해 주파수 영역으로 변환하여 추출한다. 특징 벡터는 폐곡면 표면점과 중심점과의 관계를 나타내는 내측거리값을 활용하므로 위치 이동에 불변이고 내측거리값은 퓨리에 변환 전 정규화되기 때문에 크기 변화에 불변이며 퓨리에 변환 후 파워 스펙트럼을 적용하여 회전 변화 불변임을 보여주고 있다. 실험 결과 위치 이동, 크기 변화, 회전 변화에 불변임을 알 수 있고 서로 상이한 객체간에 변별력이 있어 객체 고유의 특징 벡터로써 활용이 가능함을 제시한다.

• 한국농림기상학회지
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• 제13권4호
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• pp.176-184
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• 2011

본 연구에서는 폐쇄집수역의 냉기호 현상을 기존의 냉기집적효과와 연계하여 일 최저기온 분포를 모의할 수 있는 방법을 제시하였다. 집수역 내 찬 공기가 담길 '그릇'의 용적을 계산하고 '그릇'안에 집적되는 냉기량을 고도에 따라 표현하였다. 기존의 계곡지형 냉기류에 냉기호를 합산하여 냉기집적으로 인한 기온하강분을 계산하였다. 이때 냉기호의 '수면'은 일교차 조건에 따라 변화시켰다. 이 방법을 검증하기 위해 경남 하동군 악양계곡의 200m 이하 냉기호 형성지역에 기상관측기 10대에서 1분 단위로 기온을 측정하였다. 5월 17일 새벽에는 형제봉 정상에서 적외선 영상 복사계로 지면온도분포를 획득하였다. 개선된 소기후 모형을 적용하여 0530 LST의 기온 분포를 30m 해상도로 추정한 결과 그 양상이 적외선 열영상 분포와 유사하였다. 10개 기상관측지점에 해당하는 격자의 기온추정값을 추출하여 실측값과 비교한 결과, MAE는 1.01에서 0.60으로, RMSE 1.30에서 0.71으로 감소하여 집수역 출구에 가까운 저지대 평야부분에서 발생하는 기존 방법에 의한 오차가 개선되었다.

• 전기학회논문지
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• 제64권2호
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• pp.310-314
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• 2015

To improve the optical performance of the backlight unit with light guide plate(LGP), we investigated the effects of LGP patterns on the brightness and viewing angles properties of the backlight unit. We designed several patterns of LGP and calculated their optical properties by the optical simulation. The results reveal that the highest brightness and wide viewing angle was achieved with the extended-closed-polygon diffusion pattern and upper triangle prism pattern of the LGP.

• 한국항만학회지
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• 제13권2호
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• pp.409-418
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• 1999

Gamcheon Bay has complicated and unique flow pattern which is affected by topography characteristics of a semi-closed bay and warm water discharge from the power plant located at the bay. It is very important to consider warm water discharge with tidal period and wind effects, which are mainly acting on the surface flow patterns in Gamcheon Bay. The results of observation show as follows; i) Because Gamcheon bay has much elongated shape to the north-south direction and narrow entrance with two separated breakwaters, the flow is very weak inside the bay. ii) The main flow path is at the west side of the bay. The direction of flood current is northward along the west side of the bay and the direction of ebb current is southward along the west side of the bay. The southward direction of warm water discharge has curved to the west side of the bay. iii)At the period of flood current for neap tide, the flow direction is southward in the bay, which is thought by the effects of warm water discharge. But at the bottom layer, the effects of tidal current reached to the middle of the bay, and showed features like eddy. iv) The wind effect is very strong, especially, prominent in the west and east side of the bay.

• PNF and Movement
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• 제7권3호
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• pp.17-27
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• 2009

The purpose of this study was to investigate the effect of close kinetic chain(CKC) and open kinetic chain(OKC) posion on proprioceptive neuromuscular facilitation applied to the unilateral upper extremity on the muscle activation of lower extremity. All subjects were randomly assigned to two groups: open kinetic chain group(n=5),closed kinetic chain group(n=5). All participants were PNF patterns applied on the unilateral upper extremity in all subjects were the kinetic chain(CKC) and open kinetic chain(OKC) posion on flexion/abduction/external rotation. The hold and approximation techniques for the irradiation were applied to end range. All measurements for each subject took the following tests: pre-test, post - test in 4weeks, post-testin 8weeks. EMG data was collected from the vastus medialis, tibialis anterior, biceps femoris, and gastrocnemius muscle of both lower extreamity using surface EMG system, Each EMG value in individual muscle was normalized for maximal voluntary contraction. The data were analyzed using Two-way analysis of variance(ANOVA) with repeated measures to determine the statistical significances. The results of this study are summarized as follows. First, during for close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application, all of the %MVIC values of close kinetic chain and open kinetic chain posion increased sign ificantly compared(p<0.05). Second, The close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application was significantly increased with in the intervention period(p<.05). Third, there was a no significant open kinetic chain posion on PNF pattern application of sing muscle group with in the intervention period.(p<0.05) there was a significant close kinetic chain posion on PNF pattern application of sing muscle group with with in the intervention period(p<0.05). Forth, interaction of the exercise position and muscle was also significant. Post-hoc tests revealed that the activation levels of vastus medialis muscle and tibialis anterior muscle was higher in the closed kinetic chain position(p<.05). that the activation levels of vastus medialis and gastrocnemius muscle was higher in the open kinetic chain position(p<.05). In conclusion, it was found that the application of PNF patterns to the unilateral upper extremity effect on the muscle activation of lower extremity and both open kinetic chain exercise and closed kinetic chain exercise was significantly increased muscle activity. Further studies are needed to analyzed long term effects and subjects resulting from these changed.

• The Korean Journal of Ecology
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• 제19권6호
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• pp.529-541
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• 1996

During the period of December 1992 (winter-spring) and from February 1995 (winter-spring), the leaf processing rates of oak (Quercus serrata) and tulip (Liriodendron tulipifera) tree was investigated in the headwater streams in southeastern part of Korea in conjunction with the distribution pattern of macroinvertebrate fauna. Using two types of bags ($10\times30cm$ with 5 g of dry leaves; open bag with holes, closed bag without holes), decomposition rates of oak and tulip tree by shredder and/or microbiota at a reatively undisturbed 2nd-order stream were compared, Regardless of leaf type, leaves in the open bage decomposed slightly faster than those in the closed bags. In the 1992 experiment, osk leaves decomposed much slower than tulip leaves (after 138 degree days, osk : closed, 0.006% loss/day ; open, 0.008 ; tulip: closed, 0.021 ; open, 0.023; n=2). The of the first experiment using oak leaves in 1995 were similar to those of the first experiment (after 151 degree days, oak: closed, 0.005% loss / day; open, 0.006; n=6). Over 50% of invertebrates from 122 leaf pack samples collected from 12 streams during the winter period of 1994 were identified as shredders (shredder, 56.2; collector, 32.7; scraper, 8.65; predator, 2.45%). Among shredders, Gammarus sp. and Tipula sp. were dominant species in terms of number and biomass (8.2 ind./g, 1.0 ind./g AFDW of leaves). Among many physico-chemical parameters, the width of stream channel was found to be the most influential factor in the distribution of Gammarus and Tipula (Gammarus: r=-0.34, P<0.001;Tipula:r=0.40, P<0.001). Considering the fact that oak is one the dominant riparian vegetation in the southeastern part of korea, the patterns of oak processing and shredder distribution shown in theis study may well represent some of the important characteristics of headwater steams in southeastern Korea.

• 한국의류산업학회지
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• 제23권5호
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• pp.634-644
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• 2021

This study aims to propose various ways to utilize CLO, which focuses mainly on the production of 3D virtual samples, by comparing it with the pattern drafting functions of Four apparel CAD experts, who have teaching experience in YUKA and CLO, participated in a focus group interview, and a basic bodice prototype drafting was carried out by each participant to evaluate the pattern drafting functions of YUKA and CLO. The result of this study showed that the pattern drafting tools of YUKA are subdivided since YUKA is a CAD tool inherently specialized in pattern making. Though CLO provided a relatively limited pattern drafting menu compared to YUKA, it was found that pattern drafting could be accomplished with the help of supplementary tools and functions. This finding suggests that each CAD offers the corresponding tools for the same use of menus or functions in the prototype drafting process. The major difference between YUKA and CLO is that YUKA defines the pattern area by a set of line segments, whereas CLO utilizes an outline composed of closed curves. YUKA provides various specific tools according to the options such as angles, straight lines, and curves, while CLO produces the same results using combinations of a limited number of tools. Compared with YUKA, the advantage of CLO is its user-friendly task environment such as the Windows-based user interface, from the usability perspective. This study concludes that pattern drafting education using CLO would help not only industrial 3D design practitioners but also pattern education in academia

• 대한기계학회논문집A
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• 제24권1호
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• pp.118-123
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• 2000

Most quadruped walking robots under current research are individually controlling every joint ic make them step or walk according to an integrated strategy. Such methods are characterized by at least one pair of an actuator and a sensor installed per each 'oint so that the robots weigh execssively and move inefficiently in terms of energy expenditure. In addition, the task of controlling all the joints simultaneously is quite complex and prone to destabilize the robot motion. These respects keep the existing walking robots away from realistic applications such as transportation even if they have potentially, outstanding adaptability to swamps or uneven terrains as opposed to wheeled vehicles. So, this paper presents a new conceptual quadruped robot developed to walk and steer only with a minimal number of actuators owing to a closed-chain mechanism. To prove its actual performance including the adaptability to various types of terrains. experiments are done with the mammal-type prototype. And. it is also shown that the same concept can be easily extended to carry out different gait forms. for instance, that of spiders only with minor modifications.

• Journal of Advanced Marine Engineering and Technology
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• 제23권6호
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• pp.770-777
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• 1999

In this study a phase diagram has been used to investigate the unsteadiness of two-dimensional lid-driven closed flows within a square cavity for twelve Reynolds numbers; $7.5{\times}10^3,\; 8{\times}10^3,\; 8.5{\times}10^3,\; 9{\times}10^3,\; 9.5{\times}10^3,\; 10^4,\;1.5{\times}10^4,\;2{\times}10^4,\; 3{\times}10^4,\; 7.5{\times}10^4$ and $10^5$. The results indicate that the first critical Reynolds number at which the flow unsteadiness of sinusoidal fluctuation appears from the temporal variation of total kinetic energy curves is assumed of sinusoidal fluctuation appears form the temporal variation of total kinetic energy curves is assumed to be in the neigh-bourhood of $Re=8.5{\times}10^3$ The second critical Reynolds number where the periodic amplitude and frequency collapse to random disturbance being existed around $Re=1.5{\times}10^4$ The exponentially decreasing vortices formed at the lower two corners are found commonly at the time-mean flow pattern of $Re=3{\times}10^4$.

• 음성과학
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• 제4권2호
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• pp.91-102
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• 1998

The present study attempted to modify the conventional Melodic Intonation Therapy (MIT) in three aspects: number of syllables of adjacent target utterances (ATU), melody patterns of ATU, and initial listening of melody and intoned speech with the eyes closed. The modified Melodic Intonation Therapy (MMIT) was applied to two severe Korean aphasics. The patients exhibited a severely nonfluent aphasia resulting from a left CVA(Cerebrovascular Accident). The purpose of the modification was to avoid perseveration and improve reflective listening skills. First, the treatment program avoided ATU with the same number of syllables. Second, four different patterns of melody were developed: rising type, falling type, V-type, and inverted V-type. One type of prosodic pattern was preceded and followed by another type of melody. These two variations were to decrease perseverative behaviors. Finally, the patients kept their eyes closed when the clinician played and hummed a target melody at the initial stage of the program in order to improve reflective listening skills. A single-subject alternating treatment design was used. The effects of MMIT were compared to the conventional MIT. Differing the number of syllables and the type of melodic patterns decreased perseverative behaviors and produced more correct names. The initial listening of the target melody with the patients' eyes closed seemed to increase their attentiveness and result in a more fluent production of target utterances. Probable reasons for the effectiveness of MMIT were discussed.