• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1991.04a
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• pp.17-22
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• 1991

최근 기계장치로부터 발생하는 소음을 감소시키는 새로운 방법으로서, 능동 적으로 소음을 제어하는 방법에 대한 연구가 활발히 진행되고 있다. 이것은 원하지 않는 소음을 그 신호의 역위상을 갖는 부가음을 이용하여 능동적으 로 감쇠시키는 방법으로서, 저주파수 대역에서 비효율적인 수동적인 방법인 소음기둥에 대한 대안으로 많은 학자들의 관심의 대상이 되어 왔다. 초기에 는 소음을 줄이기 위해 요구되는 여러가지 음향요소의 전달함수를 제어하는 데 대한 불가능성으로 인해 능동 소음제어에 대한 실질적인 발전이 지연되 어 왔으나 최근 마이크로 컴퓨터를 비롯한 전자공학의 발전으로 인해 적응 신호처리 분야가 등장하게 되었으며, 음향계의 소음을 원하는 수준까지 제어 하는 능동 소음제어의 실시간 구현이 가능하게 되었다. 그 중에서도 음이 1 차원적으로 전파한다고 볼 수 있는 길이가 긴 덕트구조물에서의 능동 소음 제어는 가장 기본적이며 현실적으로 자동차 배기계나 냉동.공조설비에 있어 서 실용적으로 적용할 수 있는 문제임 만큼 많은 연구가 이루어지고 있다. 이러한 능동 소음제어 방법을 음향계에 적용하였을 때, 부가적인 음을 발생 하는 제어용 스피커로 인해 입력마이크로폰으로의 음향궤환이 존재하고 이 에 따라 제어계가 불안정해질 수 있으며, 또한 변환기의 사용으로 인한 부가 적인 전달함수가 존재하므로 이에 대한 중요한 의미를 갖고 고려하여야 한 다. 본 연구에서는 적응 필터링 이론에 의한 소음원의 입력신호에 대한 최적 한 예측으로써 부가음을 발생시키고, 입력신호 및 제어된 출력신호간의 차인 오차를 최소화 시키도록 하는 오차적응제어법을 이용한 능동소음 제어 방법 을 제시하였다. 이와 아울러 제어계의 환경변화에 따른 파라메타의 변화에 적응적으로 응답이 가능해야 하는 적응 소음제어 시스템에서, 음향궤환과 함 께 필히 고려해야 하는 부가적인 전달함수의 영향을 고려한 능동 소음제어 에 대해 연구하였다. 경량화 추세에 따라 지반이나 케이싱이 경량이거나 유연하여 회전축과 동적으로 연성된 경우 회전축-베어링-지반으로 이루어진 2중구조의 회전축 계 동특성을 해석할 수 있는 프로그램을 개발하므로서 회전 기계류의 진동 전반에 걸친 문제점에 대한 그 원인과 현상을 명확히 분석하여 국내의 전기 계류의 보다 신뢰성있는 설계 및 제작자료를 확보하는데 기여할 수 있게 하 였다.존의 small molecular Gd-chelate에 비해 매우 큼을 알 수 있었다. MnPC는 간세포에 흡수된 후 담도계로 배출되는 간특이성 조영제임을 확인하였다. 장비 내에서 반복 시행한 평균값의 차이는 대체적으로 유의한 차이가 없었으나, 다른 장비에서 반복 시행한 장비간의 사이에는 유의한 차이가 있는 경우가 더 많았다. 따라서 , MRS 검사를 소뇌나 뇌교의 어떤 절환에 적용하기 전에 각 장비 마다 정상 기준치를 반드시 얻은 후에 이상여부를 판 정하는 것이 필수적이라고 생각된다.EX> 이상이 적절한 진단기준으로 생각되었다. $0.4{\;}\textrm{cm}^3$ 이상의 좌우 부피차를 보이는 모든 증례에서 육안적으로도 해마위축이 뚜렷이 나타났다. 결론 : MR영상을 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 inflection fie이 and the maximum relaxivity value. The results shows a fluences on both inflection field

• Journal of Sericultural and Entomological Science
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• v.51 no.1
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• pp.36-40
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• 2013

To promote the consumption of mulberry fruit, we manufactured mulberry fruit wine with 'simheung' by different processing methods and analyzed cyanidin-3-glucoside(C3G) stability and antioxidant capacity. In the processing of mulberry fruit alcoholic drink, 3 minutes blanching using microwave inhibited the C3G destruction by maintaining the antioxidant capacity and inactivation of enzymes related to pigment's stability. And freeze-dried mulberry fruit was the highest C3G pigment content and antioxidant capacity. Nevertheless, this is not recommended because the economic burden of the cost of freeze-drying. In conclusion, when processing mulberry fruit wine, the addition of citric acid and the enzyme's inactivation treatment were considered more effective than storage containers (transparent glass, brown glass bottles, aluminum foil, green glass, translucent glass bottles).

• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.386-393
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• 1999

Ethanol is considered as one of the most suitable substitutes for the petroleum, since it offers attractive functional features at an economical cost. Glucoamylase producing yeasts were isolated and characterized. Based on the morphological character, carbon fermentations, assimilation of carbon and nitrate, growth on vitamine-free medicine, and urease activity, five isolates of Saccharomyces diastaticus, two isolates of Saccharomycopsis fibuligera, and two of Schwanniomyces occidentalis, and each isolate of Ambrosiozyma monospora and Lipomyces kononenkoae were identified. Among 12 isolates, one of the S. diastaticus, E3 showed the highest activity of glucoamylase and identified as Saccharomyces diastaticus. The hydrolysis of starch by the E3 strain showed the release of considerable amount of reducing sugar, along with the reduction in iodine staining capacity. The product of action of glucoamylase, glucose was determined by thin-layer chromatography. The enzyme activity was found to be stable in broad pH range of $5.0{\sim}7.0$ with optimal activity at pH $5.0{\sim}6.0$. The enzyme showed optimal antivity at $50^{\circ}C{\sim}60^{\circ}C$. Soluble starch and glucose were better carbon sources for the enzyme production than xylose and glycerol. $Na^+\;and\;Mg^{2+}$ increased the glucoamylase activity, however $Hg^{2+}\;and\;Ag^{2+}$ inhibited the activity. Soluble starch was the best substrate for the enzyme activity.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.387-398
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• 2010

Recently SMEs(small and medium enterprises) in Korea have experienced severe labor shortages. In particular, college graduates avoiding SMEs are widely spotted. According to previous studies, the main causes of the evasion by college graduates are the inferior working environment and low wages. Some studies also state that SME workers experience discrimination. However, most studies have focused only on unemployment issues of the young graduates. In this research, the results of follow-up surveys on the employment status and job conditions of recent college graduates was linked as a panel data, and the performance of the graduates was analyzed. Based on the analysis, we found college graduates who are employed SMEs are likely to have their initial career fixed to the SMEs. Second, the job separation records of the young SME workers does not show positive labor market performances such as upward movements or wage increases, and the process itself turned out to be entailed frequent separation. Third, the inferior wage level at SMEs and the fact that this effect is cumulatively amplified has been a key factor for evading SMEs. Thus, it is difficult to say that the early-stage careers in SMEs are constructive in future career development. On the contrary, the early careers at SMEs result in lower labor market outcomes, and frequent job separation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.3
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• pp.83-92
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• 2004

A continuous monitoring of textural characteristics of surface sediments, sedimentation rates and beach profile was carried out to investigate the seasonal variations of sedimentary processes in the Imjado beach, southwestern coast of Korea for two years. The beach profiles consist of steep beach face and relatively flat middle and low tide beaches. The slope of the beach face increases in summer and decreases in winter, in good accordance with the standard beach cycle. Ridge and runnel systems are well developed in the middle and low tide beaches during the summer, but these structures are replaced by mega-ripples during the winter. The sediments are fining southward as well as landward. The mean grain-size tends to be increasingly coarser during seasons of autumn and winter on the north beach and during seasons of winter and spring on the south one. In addition, the sediments are eroded on the north beach and accumulated on the south one as a whole. These are probably due to southward transportation of the sediments as long-shore current (NE-SW) runs around the coastal line of the beach. However, the seasonal variations in accumulation rates are very complex and irregular. It is considered that the Imjado beach represents in non-equilibrium state, as a result of coastal and submarine topographic changes by artificial agents and sea-level uprising associated with global warming.

• Cartoon and Animation Studies
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• s.30
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• pp.1-25
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• 2013

The present study explores the problem of the placelessness and alienation through spaces of redevelopment in South Korean animation film since the 2000's. Actual space in South Korean society has been destroyed and changed unceasingly, and, in that space, humans have experienced existential conflict. While the swift development of digital technology has transcended physical restrictions to form one great network, humans are still limited as materially based beings. The recent steps in South Korean animation film are noteworthy because sociocultural changes since the 1990's and the relationship between the individual and the system are perceived in ways different from those of the past. and , the works analyzed in the present study, reveal the special sense of place in South Korean society, where the destructive reorganization of space leads to the instability of life. By intentionally bypassing a sense of place and the authority automatically bestowed on representational images, these works prompt the viewer to reexamine the relationship between reality and images. Space in these two works are presented representationally but immediately destroyed, and humans or the characters in the works accept this unfeelingly. The loss of place, which is committed by the massive system, and listless humans' weakness and alienation in response are depicted as signs of sociocultural abnormality. By showing the destructive loss of place and individuals who respond with self-anesthesia and self-estrangement, these works open viewers' eyes to South Korean society, where not only social alienation but also self-alienation is occurring. By perceiving South Korean animation film as a sociocultural phenomenon and analyzing it through the concepts of the placelessness and alienation, the present study seeks to expand further discussions on animation film.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.36-42
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• 2005

Purpose: To investigate the arthroscopic findings, and to evaluate the clinical outcomes of the treatment of posterior internal impingement of the shoulder in baseball players. Materials and Methods: We followed up 5 cases who were diagnosed as posterior internal impingement for the mean 15 months. All of the cases complained of the pain in the posterior shoulder at late cocking, and were positive in the relocation test added by hyper-horizontal abduction at $120^{\circ}$ abduction of the arm. We sutured posterior labral tear and SLAP lesion arthroscopically, and conducted debridement for rotator cuff. Three cases were performed of anterior capsular plication and the other two were performed of thermal capsular shrinkage. Pain, range of motion, and level of return to sports activity were assessed for the results. Results: As to the arthroscopic findings, all the five cases showed the fraying in posterosuperior labrum, and two of them was accompanied with the flap tear in posterosuperior labrum and the other one was accompanied with type 2 SLAP lesion. All the cases showed the fraying in supraspinatus, and one case showed partial tear. Meanwhile, in all the cases, the rotator cuff was impinged to the labrum at $90^{\circ}{\sim}120^{\circ}$ of abduction and external rotation. As to the postoperative results, all the cases did not complain of pain or instability while pitching, and the competition was recovered to be the mean 88%($80{\sim}100%$) of that before the injury. Conclusion: Definite diagnosis for the posterior internal impingement would be possible through arthroscopic examination. Favorable outcomes could be obtained with capsular plication or shrinkage for anterior microinstability and stretching exercise for posterior capsule tightness inducing the internal impingement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6447-6454
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• 2013

Seawater intake systems have significant problems due to seawater pollution, suspended solids, unstable intake and maintenance etc. An underground type seawater intake system was newly developed to overcome the existing weaknesses and was facilitated in Gyukpo port. In this study, to check the performance of the new system, the samples for water quality and the 3-D numerical modeling test were conducted. The five times test included the COD, total nitrogen, total phosphorus, pH, and suspended solid for the intake system. The analyses show that the COD, total nitrogen, total phosphorus, PH showedminor changes before and after. On the other hand, the change in suspended solids was significant and water was purified below 5 mg/l, first level fisheries water, after. The numerical model adopted the RNG $k-{\epsilon}$ algorithm and the CFX model based on the finite volume method. The porosity algorithm was used to reproduce filtered-sand, outer diameter, and thickness. The numerical results showed that the double pipe is advantageous in that it provides a uniform pressure between the inner and outer pipe for the flow to be stable. In addition, the use of multiple intake pipes did not interfere with the discharge reduction of 0.98 at the both intake pipes compared with the central intake pipe.

• Journal of the Korean Applied Science and Technology
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• v.24 no.2
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• pp.174-181
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• 2007

In this study, $SiO_2/poly(ethylene-co-vinyl$ alcohol)(EVOH) hybrid coating materials with gas barrier property could be produced using sol-gel method. The biaxially oriented polypropylene (BOPP) substrate with surface pretreatment was coated with the prepared hybrid sols containing various inorganic silicate component by a spin coating method. Crystallization behavior of the hybrids was investigated in terms of analysis of X-ray diffraction and cooling thermogram from DSC experiment. From the morphological observation of the $SiO_2/EVOH$ hybrid gel, it was confirmed that there existed an optimum content of inorganic silicate precursor, Tetraethylorthosilicate (TEOS), to produce hybrid materials with dense microstructure, exhibiting uniformly dispersed silica particles with average size below 100 nm. When TEOS was added at below or above the optimum content, particle clusters with large domain were observed, resulting in phase separation. This morphological result was found to be in good agreement with that of oxygen permeability of the hybrid coated films. In the case of film coated with hybrid prepared from addition of 0.01 - 0.02mol of TEOS, a remarkable improvement in barrier property could be obtained, however, with the addition of TEOS more than 0.04 mol, the barrier property was dramatically reduced because of phase separation and micro-crack formation on the film surface.

• Resources Recycling
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• v.23 no.2
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• pp.3-16
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• 2014

Car exhaust $CO_2$ gas reduction and fuel efficiency of the car lighter for the current era is a big challenge. The developments of high-performance Nd magnets, Li-ion secondary battery and exhaust gas purification performance of PGM catalysts used in the lightweight EV and HEV are activated. Country in order to improve the car lighter and function that use the resources of rare metals are ubiquitous imported from China because of export supply control, as soaring prices have unstable supply and demand. Compared to the emissions from the next-generation automotive recycling, waste scarce resources need to be. This study investigated the recycling technology analysis and development of the information technology, or delivered to the researchers by giving national car industry aims to contribute to the development. Findings, pulmonary high-performance motor vehicle emissions in the exhaust gas purification PGM Catalysts, Li-ion battery and Nd magnets recycling technology, such as pre- and post-processing techniques to classify technology, pre-urban mining technology mechanical separation by screening techniques under development, the study and post-processing technology has, pyro and hydro metallurgical smelting technology is established. Waste Recycling in terms of economic efficiency of mechanical components for the intensive study of screening techniques is needed.