• Clinical and Experimental Pediatrics
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• 제52권1호
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• pp.105-110
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• 2009

목적 : 신생 백서의 저산소 허혈 뇌손상에 있어서의 erythropietin (Epo) 투여의 손상 예방 효과와 보호 기전에 철 대사가 관여하는지를 조사하고자 하였다. 방 법 : 신생 백서를 암수 구별 없이 생후 7일째에 편측 온목동맥 결찰 후 산소 농도 8%인 환경에 2시간 노출시켜 저산소 허혈을 유도하였으며 저산소 노출 직후 Epo 5,000 u/kg를 복강내 투여하였다. 이들은 저산소 허혈 유도 전 투여한 생리식염수, 철, deferoxamine 등에 따라 Epo군, Iron+Epo군, Def+Epo군, Iron+ Def+Epo군, 대조군으로 나누어 저산소 허혈 유도 후 7일에 뇌손상 정도를 비교하였다. 결 과 : Epo 투여시 뇌손상의 빈도와 정도는 대조군에 비해 감소하였다. 뇌손상의 빈도와 손상 점수로 뇌손상 정도를 비교한 결과 철 투여는 Epo의 뇌손상 예방 효과를 감소시키지 않았다. Deferoxamine 투여는 Epo 단독 투여군에 비해 뇌손상의 빈도와 정도가 경감하였으나 통계적 유의성은 없었다. 결 론 : Epo는 저산소 허혈 뇌손상에 있어 뇌손상 보호 효과를 보인다. 철 투여는 뇌손상을 악화시키지 않았으나 deferoxamine 동시 투여는 Epo 단독 투여에 비해 뇌손상의 빈도와 손상 점수가 감소하여 뇌손상 보호 효과에 철 대사가 관여할 가능성을 제시하였다.

• 한국가금학회지
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• 제33권4호
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• pp.317-321
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• 2006

본 연구는 humic substances의 급여가 산란계의 생산성과 난 특성에 미치는 영향을 알아보고자 실시하였다. 55주령 ISA brown 갈색계 252수를 공시하였고, 6주간 시험을 실시하였다. 처리구는 1) CON (basal diet),2) HS5 (basal diet added humic substances 5%), and 3) HS10 (basal diet added humic sudstances 10%)으로 처리구당 7반복 반복당 12수씩 완전 임의 배치하였다. 전 시험 기간 동안 hmic substances을 10% 첨가한 처리구는 난 생산성과 난황 직경이 대조구와 비교하여 유의적으로 감소하였다(P<0.05). 난황색은 HS10 처리구가 CON처리구와 비교하여 높게 나타났다(P<0.05). 개시시 난중은 처리구간에 차이가 없었다(P<0.05). 난각 강도에서는 HS5 처리구가 다른 처리구들과 비교하여 유의적으로 높게 나타났다(P<0.05). 결론적으로, 산란계 사료내 HS 5% 또는 10%의 첨가는 난황색 및 난각 강도를 향상시킬 수 있을 것으로 사료된다.

• 대한전자공학회논문지SP
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• 제39권1호
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• pp.97-107
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• 2002

본 논문에서는 PDA용 온라인 필기체 한자 인식기를 구현하였다. PDA는 PC보다 느린 CPU와 적은 메모리를 사용하기 때문에, 본 논문에서는 적은 연산량과 적은 메모리를 사용하면서 높은 인식률을 갖는 인식기를 개발하는데 초점을 맞추었다. 따라서, 빠른 인식을 위하여 적은 연산 과정을 갖는 인덱스 매칭 방법을 사용하였고, 필기 한자의 획순 변동과 획수 변형을 수용함과 동시에, 문자 모델의 저장을 위한 메모리를 최소화하기 위하여 유닛 재구성 방법을 제안하였다. 사전에 정의된 유닛을 사용하여 1800개의.표준 문자 모델을 설정하였다. 입력된 데이터는 전처리 및 특징 추출 과정을 거친 후 표준 문자 모델과의 획수 및 형태적 특징을 기준으로 선정된 후보 문자들과의 유사도를 측정한다. 실험 대상 문자는 중·고등학교 표준 기초 한자 1800자를 대상으로 하였으며, 획수와 획순에 구애받지 않고 정서체로 필기한 5인의 문자 셀을 사용하였다. 실험은 문자 당 평균 인식 속도와 인식률을 측정하였으며, 이 결과 문자 셀에 대한 평균 인식률 94.3%를 얻었다. 문자 당 평균 인식 속도는 MIPS R4000 CPU를 사용한 PDA에서 0.16 초의 결과를 내었다.

• 한국가정과교육학회지
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• 제4권1호
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• pp.87-95
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• 1992

The purpose of this study is to suggest how we can get over the difficulties of practical drill under experimentation concerning the units of making clothes in the curriculum of home economics. The import of this study was based on the results of the preceding studies the field of the making Korean clothes, from the standpoint of the teaching tools and teaching materials by the use of VTR, is one of the most insufficient. On the one hand, the teaching procedure here a VTR, running 34 minutes or so, was made up with the process of making Korean men’s slacks, and was led by the researcher’s own. The contents of the lesson are as follows： the shape of Korean clothes, the name of each part, the process of drawing, cutting and sewing, and the items of evaluation and arrangement. On the other hand, the two comparative groups were made to compare one with the other： One group was taught by help of VTR media, and the other by the model performance and explanation of the instructor’s own. All of the statistical data were analyzed in terms of SPSS/PC, and t-verification was made, to make difference between the two, after standard deviation was calculated according to the classified domains. The consequences of the test research are shown as below： 1. The difference of understanding was obviously made in considering that the group made a better score than the comparative one in understanding to process of making Korean clothes. 2. The difference of skill was highly made in considering that the group made a better score than the comparative one in the practical drill of making Korean clothes. 3. The difference of interests was evidentally made in considering that the group made a better score than the comparative one in the stage of making Koran clothes. Such means that the motivation and attitude of the learners was made stimulate by the Audio-Visual material than by the traditional cramming method. 4. The difference of frequency was fairly made in considering that the experimeatal group made a better score than the comparative one in the frequency of individual teaching. 5. The difference of the efficiency of time-consumption was clearly made in considering that the experimental group made a better score than the comparative one. As the results of the research above, the medium of VTR proved to more effective to the achievement of schoolwork and the strategies of teaching. Therefore, more use of VTR media will help the instructors with the difficulties of practical drill in the whole process of making Korean clothes； Widely use of VTR media in teaching will be surely more fruitfull to the unit of making Korean clothes than teaching by explanation.

• Journal of Periodontal and Implant Science
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• 제47권3호
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• pp.143-153
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• 2017

Purpose: The aim of the present exploratory study was to evaluate extraction socket healing at sites with a history of periodontal and endodontic pathology. Methods: The mandibular 4th premolar teeth in 5 adult beagle dogs served as experimental units. Periodontal and endodontic lesions were induced in 1 premolar site in each animal using wire ligatures and pulpal exposure over 3 months (diseased sites). The contralateral premolar sites served as healthy controls. The mandibular 4th premolar teeth were then extracted with minimal trauma, followed by careful wound debridement. The animals were sacrificed at days 1, 7, 30, 60, and 90 post-extraction for analysis, and the healing patterns at the healthy and diseased extraction sites were compared using radiography, scanning electron microscopy, histology, and histometry. Results: During the first 7 days of healing, a significant presence of inflammatory granulation tissue was noted at the diseased sites (day 1), along with a slightly accelerated rate of fibrin clot resolution on day 7. On day 30, the diseased extraction sites showed a greater percentage of persistent fibrous connective tissue, and an absence of bone marrow formation. In contrast, healthy sites showed initial signs of bone marrow formation on day 30, and subsequently a significantly greater proportion of mature bone marrow formation on both days 60 and 90. Radiographs exhibited sclerotic changes adjoining apical endodontic lesions, with scanning electron microscopy showing collapsed Volkmann canals protruding from these regions in the diseased sites. Furthermore, periodontal ligament fibers exhibited a parallel orientation to the alveolar walls of the diseased sites, in contrast to a perpendicular arrangement in the healthy sites. Conclusions: Within the limitations of this study, it appears that a history of periodontal and endodontic pathology may critically affect bone formation and maturation, leading to delayed and compromised extraction socket healing.

• Asian-Australasian Journal of Animal Sciences
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• 제28권6호
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• pp.807-815
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• 2015

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal $CO_2$ concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.146-153
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• 2000

The rubber crawler system for farm machine is composed of driving units such as track rollers, driving sprockets and rubber crawlers. Vibration characteristics of the rubber crawler system varies by driving speed, center of gravity, mass□moment of inertial□location arrangement of track rollers and dynamic parameters such as dynamic spring constant (k) and viscous damping coefficient (c) of a rubber crawler. In general, vibration of the rubber crawler system occurs by reason for mechanical interaction between the rubber crawler and track rollers. Because the dynamic spring constant and viscous damping coefficient vary periodically by mechanical characteristics(deformation characteristics) of the rubber crawler when track rollers drive on the between lugs of the rubber crawler. Therefore, both dynamic parameters k and c were expressed as Fourier series by authors through the shaking test of the rubber crawler and further, vibration characteristics of the rubber crawler system could be simulated analytically. However, actual values of dynamic parameters k and c are different from those obtained by the shaking test because dynamic characteristics of the rubber crawler vary by the effect of variable tension and driving resistance of track rollers. So, actual values of k and c should be identified in the condition of actual driving test. In this study, dynamic parameters such as k and c of the rubber crawler system, which are expressed as Fourier series, were identified using the Gauss-Newton Method. Therefore, validity of identified parameters k and c was discussed through the simulation using experimental data of actual driving test. As a result, in the Fourier series of dynamic parameters of spring constant k and viscous damping coefficient c, excellent parameter convergence and simulation were observed using the Fourier series' zero order and first term of the dynamic model. Furthermore, it was clarified that identification for model parameters which are fitted to actual dynamic motion (vibration) wave of the crawler system was possible by using the time series data observed in vertical and pitching motion of the crawler system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.835-841
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• 2013

Modern solid-state gyroscopes (HRG) with hemispherical resonators from high-purity quartz glass and special surface superfinishing and ultrathin gold coating become the best instruments for precise-grade inertial reference units (IRU) targeting long-term space missions. Designing of these sensors could be a notable contribution into development of Korea as a space nation. In participial, 40mm diameter thin-shell resonator from high-purity fused quartz, fabricated as a single-piece with its supporting stem has been designed, machined, etched, tuned, tested, and delivered by STM Co. (ATS of Ukraine) several years ago; an extremely-high Q-factor (upto 10~20 millions) has been shown. Understanding of the best way how to match such a unique sensor with inner glass assembly of the gyro means how to use the high potential in a maximal extent; and this has become the urgent task. Inner quartz glass assembly has a very thin indium (In) layer soldered the resonator and its silica base (case), but effects of internal resonances between operational modal pair of the shell-cup and its side (parasitic) modes can notable degrade the potential of the sensor as a whole, instead of so low level of resonator's intrinsic losses. Unfortunately, there are special combinations of dimensions of the parts (so-called, "resonant sizes"), when intensive losses of energy occurs. The authors proposed to use the length of stem's fixture as an additional design parameter to avoid such cases. So-called, a cyclic scheme of finite element method (FEM) and ANSYS software were employed to estimate different combinations of gyro assembly parameters. This variant has no mismatches of numerical origin due to FEM's discrete mesh. The optimum length and dangerous "resonant lengths" have been found. The special attention has been paid to analyses of 3D effects in a cup-stem transient zone, including determination of a difference between the positions of geometrical Pole of the resonant hemisphere and of its "dynamical Pole", i.e., its real zone of oscillation node. Boundary effects between the shell (cup) and 3D short "beams" (inner and outer stems) have been ranged. The results of the numerical experiments have been compared with the classic model of a quasi-hemispherical shell band with inextensional midsurface, and the solution using Rayleigh's functions of the $1^{st}$ and $2^{nd}$ kinds. To guarantee the truth of the recommended sizes to a designer of the real device, the analytical and FEM results have been compared with experimental data for a party of real resonators. The consistency of the results obtained by different means has been shown with errors less than 5%. The results notably differ from the data published earlier by different researchers.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제14권1호
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• pp.81-95
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• 2011

수학적 힘과 수학에 대한 긍정적인 태도를 가진 21세기에 적합한 인간을 육성하기 위해서는 학생 개개인의 능력과 수준에 맞는 균등한 학습의 기회가 제공되어야 하며, 특히 학습 부진아들에게는 이러한 수학 교육이 더욱 절실하다. 본 연구는 각 단계의 최적의 학습 자료라 할 수 있는 교과서를 활용하여 이전 학년의 교과서를 분석하고, 점검하는 활동이 학생의 수학 학습 능력과 수학적 성향에 어떤 변화를 가져오는지에 대해 살펴보는데 그 목적이 있다. 본 연구를 통하여 이전 학년의 교과서를 활용한 수학 학습 부진아 지도 방법이 수학 학습 부진아에게 할 수 있다는 신념을 갖게 하고 수학적 연결성을 강화시켜 주며, 핵심적인 내용을 스스로 파악하는 습관을 가지게 하는 것을 알 수 있었다.

• 대한바이러스학회지
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• 제27권1호
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• pp.39-47
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• 1997

A large number of viruses belonging to Genus Hantavirus in Family Bunyaviridae are etiologic agents for hemorrhagic fever with renal syndrome (HFRS), or hantavirus pulmonary syndrome (HPS). Hantaan (HTN), Seoul (SED), Belgrade (BEL), Puumala (PUU) serotype viruses are well known causative agents for HFRS in Eurasian continent. Among those viruses Hantaan and Seoul serotypes are well known to cause HFRS in Korea, but there are some sporadic incidence by other than Hantaan or Seoul viruses. Recently we have developed the combined Hantaan-Puumala virus vaccine to prevent world-wide occuring HFRS. This combined vaccine is formalin inactivated, suckling mouse and suckling hamster brain extracts for Hantaan and Puumala viruses, respectively. Protein contents of this purified candidate vaccine is $27\;{\mu}g/ml$, which contains 1,024 ELISA antigen units to each virus, but content of myelin basic protein which is causing experimental allergic encephalomyelitis is less than 0.1 ng/ml. Thirty hamsters were given twice at one month interval intra-muscularly and bled on 30 days after each vaccination from retro-orbital sinus vein. Antibody titers were tested against 5 major serotype viruses, Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses by IFA and PRNT. The mean IF antibody titers on 30 days after primary shot were 78.4, 68.8, 68.8, 37.9, and 15.6; mean neutralizing antibody titers were 65.4, 12, 6.1, 65.6 and 0.5 against Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses, respectively. The mean IF antibody titers on 30 days after booster shot were 686.9, 567.5, 550.4, 516.3, and 430.9; and neutralizing antibody titers were 710.8, 41.9, 24.3, 409.9, and 1.6 against Hantaan, Seoul, Belgrade, Puumala and Sin Nombre viruses, respectively.