• Journal of Aquaculture
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• v.3 no.1
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• pp.49-63
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• 1990

A population ecological study was carried out to estimate survival and growth rates, biomass, biological production and turnover ratio of cultured sea squirt, Halocynthia roretzi, by growth stages, using data from in situ culture experiment off Hansando in the southern part of Korea from February 1985 to July 1986. The squirt population followed an exponential decay function and the instantaneous coefficient of total mortality (Z) was estimated to be 0.0614 $month^{-1}$(Var (Z) = 0.000126). Growths in total weight and meat weight of squirts were expressed as linear functions during the period of culture experiment. The growth of squirts showed a negative correlation with the water temperature. The mean biomass per string ranged from 2.14 kg for March of the first year to 16.26 kg for March of the next year. The biological production per string was estimated to range from 3.28 kg for the first summer (June - July) to 6.46kg for the first late winter (February-March). The peak of turnover ratio occurred in the late winter (February-March) as 3.013 and the ratios sharply declined thereafter. Based on the results of this study, management implications for culturing sea squirts were also suggested. The optimum harvest time ($t_{mb}$) when the peak biomass in terms of total weight occurred was estimated to be late June of the second year, which corresponded to 16.7 months after the main hanging. However, the time when the peak biomass in terms of meat weight was occurred was early July of the second year. The maximum harvest biomass was 17.4 kg per string in terms of total weight and 6.3 kg per string in terms of meat weight. In conclusion, the process of culture should be conducted on the basis of the knowledge of population ecological theories as shown in this study.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.86-111
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• 2011

Wan is a tableware in which boiled rice or soup, side dish are put, and it is a representative model which shows the development of personal tableware. From the establishing period of Hanseong Baekje, the form of wan which is Jung-do Style(中島式) Plain Pottery of previous period Proto-Three Kingdoms Period was succeeded to, but wan is produced and used as a wan baked in the kiln, which is far development of the producing technique including hardness and clay. By and large, the size of $0.3{\sim}0.4{\ell}$ was the majority and the production technique of wan which used carefully selected soft quality clay are largely confirmed to be two methods which are, first, basic method by which on a clay tablet on the rotating table, clay band is accumulated and moulding is finished, and second, the new method which had the same basic moulding as that of basic method but in the last stage takes wan off the rotating table and reverse it to trim the bottom and remove the angle of flat bottom. The former, basic production method is the classical production method since wan of Jung-do Style Plain Pottery and wan was produced and used for all periods of Hanseong Baekje. On the other hand, the latter is the production method obtained through form imitation of China made porcelain flowed into through interchange between Baekje and China, and through comparison with Chinese chronogram material it is estimated to have been produced and used after middle of 4th century. Therefore it can be known that the Baekje people's demand for China made articles was big and imitation pottery was produced and used with Baekje pottery. In addition, bowl with outward mouth are confirmed in multiple number in Lakrang(樂浪) pottery wan and it is assumed that wan was the form produced under the influence.

• Polymer(Korea)
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• v.39 no.1
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• pp.33-39
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• 2015

Olmesartan affiliated to biopharmaceutics classification system class 2 is a poorly water soluble drug. For this reason, olmesartan showed a low bioavailability and a lot of difficulties in the process of designing the pharmaceutical formulation. We prepared the solid dispersions of olmesartan. We confirmed the dissolution rate of drug which was prepared by manufacturing. The pharmaceutical formulation of solid dispersions was designed by using PVP as water soluble polymer. We analyzed morphological feature of solid dispersion by employing a scanning electron microscope. Then, the crystalline property of solid dispersion was confirmed through X-ray diffraction and differential scanning calorimeter. Also, the chemical change of solid dispersion was confirmed by the Fourier transform infrared spectroscopy. In vitro dissolution test was used to analyze the dissolution rate of solid dispersion. The prepared solid dissolution olmesartan confirmed the dissolution rate in the pH 1.2. It was compared with olmetec and improved dissolution rate through solid dispersion.

• The korean journal of orthodontics
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• v.37 no.6
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• pp.407-420
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• 2007

The aim of this study was to compare the differences in closing extraction spaces between maxillary first premolar and second premolar extractions using 3-dimensional finite element analysis (FEA). Methods: Maxillary artificial teeth were selected according to Wheeler's dental anatomy. The size and shape of each tooth, bracket and archwire were made from captured real images by a 3D laser scanner and FEA was performed with a 10-noded tetrahedron. A $10^{\circ}$ gable bend was placed behind the bull loop on a $0.017"{\times}0.025"$ archwire. The extraction space was then closed through 12 repeated activating processes for each 2mm of space. Results and Conclusions: The study demonstrated that the retraction of anterior teeth was less for the second premolar extraction than for the first premolar extraction. The anterior teeth showed a controlled tipping movement with slight extrusion, and the posterior teeth showed a mesial-in rotational movement. For the second premolar extraction, buccal movement of posterior teeth was highly increased.

• Development and Reproduction
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• v.7 no.1
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• pp.29-34
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• 2003

Anatomical and histological observations were used to examine the morphological differentiation and development of the digestive tract during ontogenesis in tiger puffer, Taklyugu rubripes. Before hatching, the digestive tract was located between yolk sac and notochord of embryo. Newly hatched larvae had a straight tubular digestive tract. The larval mouth opened at 2 days after hatching (DAH). At 4 DAH, sphincters separated the digestive tract into the esophagus, anterior intestine, mid-intestine and rectum, and the anus was opened. At 5 DAH, the larval intestine bent between the anterior and intermediate parts and mucous cells developed in the esophageal epithelium. At this time yolk sac was absorbed completely. At 6 DAM, the digestive tract was differentiated into the U type with expansion of the anterior intestine toward the head of the larvae. At 10 DAH, the expanding anterior intestine became wider and a elliptical. At 15 DAH, the anterior intestine was divided into two portions by invagination of dorsal epithelium and the mid-intestine was convoluted dorsally. At 21 DAM, the frontal portion of the anterior intestine formed a differentiated expansion sac. At 24 DAH, the second convolution was observed in the anterior part of the posterior intestine. At 30 DAH the expansion sac was extended longitudinally and the digestive tract took on the form seen in adult fish.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.490-497
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• 2007

Odontoma is defined as a benign odontogenic tumor containing enamel, dentin as well as cementum and constitued 22% of all odontogenic tumors. Although the lesions are commonly asymptomatic, they may be discovered routine radiographic examination. Odontomas often cause disturbances in the eruption of teeth such as, impaction or delayed eruption, retention of primary teeth, or abnomalities in the position of the teeth such as tipping or displacement of adjacent teeth. Radiologically, odontomas manifest as a dense radiopaque lesion surrounded by a thin radiotransparent halo. However, in some cases, radiopacity was not quite clear and images of the teeth shadowed very tiny odontomas. And at early development stages of odontoma, calcification remains immature and is difficult to diagnose on radiographs. This suggests that when delayed eruption of the teeth is found, periapical radiographs should be taken to clarify whether any small area of radiopaque material exists. This case report shows tiny odontomas involving an impacted tooth and crowding and we remove the tiny odontoma surgically.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.36-42
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• 2016

Recently, many 3D contents have been produced through the multiview camera system. In this system, since a difference of the viewpoint between color and depth cameras is inevitable, the camera parameter plays the important role to adjust the viewpoint as a preprocessing step. The conventional camera calibration method is inconvenient to users since we need to choose pattern features manually after capturing a planar chessboard with various poses. Therefore, we propose a semi-auto camera calibration method using a circular sampling and an homography estimation. Firstly, The proposed method extracts the candidates of the pattern features from the images by FAST corner detector. Next, we reduce the amount of the candidates by the circular sampling and obtain the complete point cloud by the homography estimation. Lastly, we compute the accurate position having the sub-pixel accuracy of the pattern features by the approximation of the hyper parabola surface. We investigated which factor affects the result of the pattern feature detection at each step. Compared to the conventional method, we found the proposed method released the inconvenience of the manual operation but maintained the accuracy of the camera parameters.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.3
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• pp.199-207
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• 2013

In hydrographic survey, data surveyed with multibeam system includes various errors due to multiple factors. These are corrected by a calibration called patch test, and if existing method is used, the test needs to be conducted for about 8 times for precise system calibration. For more prompt and precise multibeam system calibration, the exact offset of a ship was determined using terrestrial laser scanning and TS surveying, which was used as the initial input for the patch test. In the result, the error of closure was 0.001 m or less for TS surveying and backsight error was 0.005 m or less for scanning. All the surveying data based on the same local coordinate was converted into vessel reference coordinate during which R-square for all rotation angles was 0.99 or higher and standard deviation was 0.008 m or less. Finally, in a patch test using calculated offset of sensors and motion sensor offset, the offset of MBES transducer satisfied manual on hydrography only with 1-time calibration. With these results, it is thought that terrestrial laser scanning and TS surveying can fully be utilized for multibeam system calibration.

• Journal of Biosystems Engineering
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• v.7 no.1
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• pp.62-72
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• 1982

이 연구(硏究)는 정백과세중(精白過稅中)에 발생(發生)하는 도정산물(搗精産物) 즉, 정백미(精白米), 미당(米糖), 쇠미등(碎米等)의 발생(發生)을 조사(調査)함으로써 현미(玄米)의 정백(精白)이 진행(進行)되는 과정(過程)을 밝히고자 함이다. 본(本) 실험(實驗)에서는 분풍마찰식(噴風摩擦式) 정미기(精米機)를 사용(使用)하였으며, 정미기(精米機)의 롤러 회전속도(回轉速度)를 850rpm으로 고정(固定)하고 출구저항(出口抵抗)은 3가지 수준(水準)으로 변화(變化)시켰다. 한편 이 실험(實驗)에 사용(使用)된 벼는 밀양 23호(號)로써 전형적인 통일계품종(品種)의 일종(一種)이다. 매순환(每循環)마다 생산(生産)되는 정백미(精白米) 및 부산물(副産物)로부터 sample를 채취(採取)하여 미당(米糖), 대소쇄미(大小碎米), 완전미(完全米) 및 도정수율(搗精收率)을 분석(分析)하였다. 실험결과(實驗結果)를 요약(要約)하면 다음과 같다. 1) 전체당층(全體糖層)의 75%가 2번째 순환이내(循環以內)에서 제거(除去)되었다. 당층제거율(糖層除去率)은 출구저항(出口抵抗)에 크게 영향(影響)을 받으며, 높은 출구저항(出口抵抗)에서 높은 당층제거율(糖層除去率)을 보였다. 2) 대쇄미(大碎米)의 발생(發生)은 대부분 정백과정(精白過程) 초기단계(初期段階)에서 이루어 졌으며, 완전미(完全米)로 부터의 새로운 쇄미발생(碎米發生)은 순환(循環)이 반복(反復)됨에 따라서 급격(急激)히 감소(減少)하였다. 출구저항(出口抵抗)과의 관계(關係)는 출구저항(出口抵抗)이 증가(增加)할수록 대쇄미(大碎米)의 발생(發生)도 증가(增加)하였다. 3) 미당집적기(米糖集積器)로부터 채취(採取)한 sample에서 측정(測定)한 소쇄미(小碎米)는 양적(量的)으로 다른 도정산물(搗精産物)에 비(比)해 적은 편이었다. 8%의 미당(米糖)이 제거(除去)된 후(後) 소쇄미(小碎米)는 현미중량(玄米重量)의 0.6% 이하(以下)로 나타났다. 4) 도정수율(搗精收率)과 완전미수율(完全未收率)은 어느 정도 출구저항(出口抵抗)의 영향(影響)을 받는 것으로 나타났다. 출구저항(出口抵抗)이 증가(增加)함에 따라서 특히 완전미수율(完全未收率)은 감소(減少)하는 경향(傾向)을 나타냈기 때문에 백미(白米)의 질적저하(質的低下)를 막기 위해 높은 출구저항(出口抵抗)(본(本) 실험결과(實驗結果)에 의(依)하면 85g/$cm^2$)을 사용(使用)하는 것은 부적당(不適當)한 것으로 사려(思慮)된다. 5) 백도계(百度計)의 측정치(測定値)와 미당제거정도(米糖除去程度)(정백도(精白度)) 사이에는 고도(高度)의 상관관계(相關關係)가 있었다. 그러므로 "KETT"제(製) 백도계(百度計)는 정백미(精白米)의 정백도(精白度)를 판명(判明)하는데 사리(使利)하게 사용(使用)될 수 있다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.04a
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• pp.235-239
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• 1996

분류가 모서리에 충돌할 때 발생하는 순음성 소리인 쐐기소리(edgetone)는 공력음향의 대표적인 현상으로서 지금까지 수많은 연구가 있어 왔으며 그 대부분의 특성이 규명되었다고 할 수 있다. 쐐기소리의 발생기구인 되먹임(feedback) 이론을 처음으로 제안한 이는 Powell로서 그는 되먹임사이클의 위상조건에 의하여 주파수특성에 관한 모델을 제안하였으며, 최근 그 모델의 위상인자에 관하여 Kwon은 새로운 값을 제안한 바 있다. 그런데, 쐐기소리의 이론은 주로 분류가 쐐기나 벽에 충돌할 경우에 집중되어 왔으며 분류가 원통에 충돌하여 발생하는 경우에 관한 연구는 Krothapalli의 초음속분류에 관한 연구와 Mochizuki등의 아음속분류에서 원통지름의 영향에 관한 연구를 들 수 있을 뿐이다. Mochizuki등은 원통의 지름이 노즐의 높이보다 작은 경우에 쐐기 소리의 주파수가 원통의 와류이탈(vortex shedding) 주파수와 같은 것을 관찰하였다. 그러나 분류와 원통이 작용하여 발생하는 쐐기소리의 주파수 특성에 관한 이론적 해석을 시도한 연구는 없으며 또한 방사음장의 특성에 관하여도 Han과 Kwon에 의한 모델이 발표된 바 있으나 실험적으로 입증되지 못하였다. 따라서, 본 연구의 목적은 2 fig.1과 같이 2차원 분류가 원통에 충돌할 때 발생하는 쐐기소리의 주파수특성의 정량적인 모델을 세우고 방사음장의 지향특성의 이론 모델을 확립하는 것이다. 먼저 주파수특성을 실험하고 되먹임이론을 적용하여 분석하므로써 유효음원의 위치를 구하고 또한, 수직벽에 작용하여 발생하는 충돌음(impinging tone)의 경우를 실험하여 주파수특성을 비교 고찰하므로써 유효음원의 위치에 관한 이론을 입증한다. 아울러 원통과 평면벽의 각 경우에 방사음장의 지향특성을 측정하고 고찰한다.2,5,6]을 단계별로 고찰하여, 점점 까다로워져 가는 선박 진동규제[3,4]에 대처하고 승무원의 안락성에 대한 욕구, 구조물의 안전성, 장비의 성능보존이 만족되는 저진동 선박의 건조를 위해 향후 해결해야할 과제들을 도출하여 선박진동분야이 연구개발 방향을 제시하고자 한다. 하는 것은 진단의 정밀도에 문제가 있을 것으로 생각된다. 따라서 언어적진리치가 도입되어 [상당히 확실], [확실], [약간 확실] 등의 언어적인 표현을 이용하여 애매성을 표현하게 되었다. 본 논문에서는 간이진단 결과로부터 추출된 애매한 진단결과중에서 가장 가능성이 높은 이상원인을 복수로 선정하고, 여러 종류의 수치화할 수 없는 언어적(linguistic)인 정보ㄷㄹ을 if-then 형식의 퍼지추론으로 종합하는 회전기계의 이상진단을 위한 정밀진단 알고리즘을 제안하고 그 유용성을 검토한다. 존재하여도 모우드 변수들을 항상 정확하게 구할 수 있으며, 또한 알고리즘의 안정성이 보장된 것이다.. 여기서는 실험실 수준의 평 판모델을 제작하고 실제 현장에서 이루어질 수 있는 진동제어 구조물에 대 한 동적실험 및 FRS를 수행하는 과정과 동일하게 따름으로써 실제 발생할 수 있는 오차나 error를 실험실내의 차원에서 파악하여 진동원을 있는 구조 물에 대한 진동제어기술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but strongly in fluences on both