• 한국과학교육학회지
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• 제19권4호
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• pp.674-683
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• 1999

본 연구의 목적은 문제를 스스로 진술하고 방법 및 해를 스스로 찾는 자유 탐구와 문제와 방법이 모두 주어진 안내된 탐구의 경우, 학생들의 변인 판별 및 통제에 대한 생각을 과학자와 비교하기 위한 것이다. 연구 대상은 서울 소재 중학교 1학년이다. 자유 탐구의 경우 3개 반에서 과학 성적이 상위 1/3 이내에 드는 학생들을 연구 대상으로, 연구자가 개발한 설문지를 이용하여 변인 판별과 실험 설계를 통한 변인 통제를 조사하였다. 안내된 탐구에서는 반 전체를 그 대상으로 하였다. 안내된 탐구의 경우 3반 모든 학생을 대상으로 하여, 대상 학생들에게 교과서 실험 제목과 과정을 제시하고 변인을 판별하도록 하였다. 안내된 탐구의 경우, 제시된 실험에서 제시된 문제의 변인이 두 개 임에도 불구하고, 문제와 관련된 변인을 하나 이상 판별한 학생들이 매우 적었다. 자유 탐구의 경우, 판별한 변인의 수는 2-3개로 증가하였으나 실험 설계를 통하여 학생들의 변인 통제를 조사한 결과, 독립 변인과 종속변인을 혼동하거나, 오개념으로 적절하게 판별하지 못하며, 공변화시키는 모습을 보였다. 이러한 결과로부터 학생들의 변인 판별 및 통제에 대한 2가지 수준을 판별하고, 이를 과학자들의 생각과 비교하였다.

• 대한기계학회논문집B
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• 제35권10호
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• pp.981-987
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• 2011

단기통 직접분사 가솔린엔진의 성층연소 조건에서 연소실험을 수행하였다. 각 분사압조건마다 실화가 발생하지 않는 성층연소가능 분사시기영역이 존재하였으며 이는 혼합기 형성과정의 분위기압에 따른 영향으로 판단하였다. 연소효율은 분사시기를 지각할수록 증가하며 32~28 CAD BTDC에서 최대값을 갖고 이후 감소하는 경향을 보였고 분사압이 높을수록 높은 연소효율이 나타났다. 이러한 연소효율의 경향은 IMEP와 다른 경향을 보였으며 그 이유는 높은 연소효율 조건에서 연소상이 진각되어 음의 일이 증가하였기 때문으로 판단된다. Smoke의 배출은 분사시기가 지각됨에 따라 증가하였으며 높은 분위기 압에서 국부적으로 농후한 영역이 증가하였기 때문으로 생각된다. NOx 배출도 분사시기를 지각함에 따라 감소하였으며 연소상의 지각으로 최대 연소실압력과 온도가 감소하였기 때문으로 생각된다.

• 설비공학논문집
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• 제13권2호
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• pp.115-121
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• 2001

Recently, the requirement of healthier and more comfortable environment makes the zoning domain more details. However, it has limitation to satisfy the thermal comfort of an individual because of the effect of the heat generation from the OA machine and partitions in indoor room. In this paper, we certify the validity of task-ambient air-conditioning system that has been developed as a new concept of personal air-conditioning system, and specify design strategies for more efficient task-ambient air-conditioning system with a specification guided by indoor environmental characteristics analyzed through experiment data. In this experiment, we changed the temperature and the quantity of air-flow in task domain to understand characteristic behavior of the thermal environment and investigate the possibility of energy saving. The experiment result is that the environment of the task area depends on the condition of supply air, and though the airflow of the low temperature is supplied with the ambient area, the personal environment and the efficiency of energy saving are improved by controlling the temperature and the quantity of the air shot around the task domain.

• 한국과학교육학회지
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• 제27권3호
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• pp.169-179
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• 2007

이 연구에서는 가설 연역적 탐구 실험이 학생들의 과학의 본성에 대한 관점 변화에 미치는 효과를 조사하였으며, 그 효과는 학습 전략에 따라 분석되었다. 연구 대상은 중학교 2학년 학생 212명이며 학생들은 실험집단과 통제집단으로 무선 배치되었다. 통제집단의 학생들은 안내된 탐구 실힘을 실시하였으며, 실험집단의 학생들은 가설 연역적 탐구 실험을 실시하였다. 연구 결과 사전 검사에서 실험 집단과 통제 집단은 과학의 본성에 대한 관점이 거의 비슷하게 나타났다. 수업을 실시한 후 실험 집단은 과학의 본성 중에서 관찰의 이론 의존성, 과학적 추론, 가설에 대한 관점이 유의미하게 변화되었다. 실험집단 중에서 피상적 전략을 주로 사용하는 학생들은 과학의 본성 중에서 가설에 대한 관점만이 유의미하게 변화되었다. 반면, 실험집단 중에서 심층적 전략을 주로 사용하는 학생들은 과학의 본성 중에서 관찰의 이론의존성, 과학적 추론, 가설에 대한 관점이 유의미하게 변화되었다.

• 대한치과보철학회지
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• 제45권1호
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• pp.1-11
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• 2007

Statement of problems: The concept of CR has also changed continuously.?In order to find out the factors that affect the centric slide, studies were carried out to compare the forms of wisdom teeth eruption, lateral movement, premature contact in CR, and anterior movement. Research and statistical methods were based on the report by the 1980 Korean dental association. Material and method: In our study, 403 dentists in their twenties and dentistry students who could understand CR and CO (and who did not receive occlusal, orthodontic treatment, without extreme caries and large prosthodontic care) were compared with the 25 year old results. A segment of line parallel to the upper incisor was marked on the lower incisor. When seen laterally, a line perpendicular to the occlusal plane was drawn on the foremost area of the upper incisor. This line was extended to the lower incisor and the two points (points at the lower and upper incisors) were used as reference points for the CO. After guiding the occlusion to the CR, two lines were marked by using the same method that was used for the CO. The point in which these lines meet became the reference point of CR occlusion Results and conclusions: Results of the experiment completed in 1980 show that all 307 research members had anterior-posterior and upper-lower displacement. Displacement measurements were $0.7{\pm}0.4mm$ for the anterior-posterior displacement, $0.99{\pm}0.50mm$ for the upper-lower displacement,0.18{\pm}0.31 mm for the lateral displacement, and $1.32{\pm}0.67mm$ for the total displacement. Results of the 2006 experiment show that all 409 research members had anterior-posterior and upper-lower displacement. The anterior-posterior displacement was $1.12{\pm}0.86mm$, the upper-lower displacement was $1.02{\pm}0.71mm$, the lateral displacement was $0.61{\pm}0.56mm$, and the total displacement was $1.80{\pm}0.99mm$. No specific differences were found between each group when comparing displacement according to the forms of wisdom teeth eruption. Since 1980, the percentage of unerupted teeth has increased from 35.16% (111/307 people) to 57.5% (236/409 people). Westernization of the Korean cranial form and intraoral structure has brought about these results. In our experiment, 26.7% (109/409 people) of the subjects were cuspid guided, while 7.3% (30/409 people) were mutually guided. No specific differences were found in the amount of displacement between the two groups. Only the subjects with anteriors coming in contact made up the largest percentage group (42.3%, 173/409 people) in our study. No specific differences were found between each group.

• 한국항공우주학회지
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• 제49권5호
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• pp.373-381
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• 2021

본 논문에서는 저속 롤링하는 유도형 탄약 모사체가 시간 지연된 측정치를 획득하였을 때 시간지연을 고려하여 탄약의 롤각을 추정하는 방법을 다루며 비행 실험을 통해 이를 검증한 결과를 소개한다. 수치적 안정화 및 잡음 제거를 위해 저역 통과 필터와 같은 후처리를 거친 측정치의 시간지연 정도를 사전에 파악하여 시간 지연의 분포를 모델링하며 이 분포를 활용한 증강 상태 칼만필터를 설계한다. 비행 실험에서는 대형 고정익 항공기를 이용해 표고 약 250m의 고도에서 수평방향으로 28m/s의 속력으로 탄약을 투하하였으며 탄약 내부의 반동차를 이용해 탄체를 롤축 회전시켰다. 상용 GPS/INS의 롤값과 제안한 방법으로 추정한 롤값의 비교를 통해 측정치 시간 지연보상을 반영한 필터 설계가 유효함을 보인다.

• 한국실내디자인학회논문집
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• 제12호
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• pp.25-32
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• 1997

The fast growth of the elderly population and nuclear families have been creating substantial needs for residential facilities of aged people in Korea. In this study, reviews on housing preference and physical constraints have been performed based on previous researches. In this study, the results of the analyses propose developmental strategies for the elderly housing in Korea as follows: 1)Housing preference and other psychological trends of Korean elderly are rooted in changeable condition of the emotion and lack of knowledge. Therefore, the housing preference of the Korean elderly should not be considered a fixed reflection ; rather, it should be regarded as a continuously adjusted trends according to later experience and emotional status after residing in the elderly care facilities. 2)Design of elderly housing should be guided within two principles of easy access and high usability. The principles also require maximazation of social interactions among frail elderly residents on age-segregated structure. 3) The experiment among 201 frail elderly shows that each shower stall should accommodate 5-by-5 feet square for wheelchair u-turn, and 48 inch height for kitchen topsink. Finally, the experiment shows that ramp slope of the ederly housing should be within 1/16 and 1/20.

• 한국수정란이식학회지
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• 제12권2호
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• pp.211-218
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• 1997

This experiment was carried out to develop the anesthetic methods for ultrasonography and a new simplified disposable needle guidance device for ovum pick-up(OPU) in cows. Three different anesthetic methods were applied as. 1) epidural analgesia only with 2% lidocaine(20~30 ml), 2) epidural analgesia with 2% under general sedation with xylazine, 3) epidural analgesia with 2% lidocaine under general sedation with detomidine. We evaluated the anesthetic effects with items such as relaxation of anal sphincter, tail movement and rectal wall, retractability of both ovaries, additional anesthesia and possibility of OPU. Through this experiment, the above three anesthetic methods were applicable to OPU, but the epidural anlagesia under general sedation with detomldine was most effective for OPU. We developed a new disposable needle guidance device with stainless steel tube. With this, disposable needles can be easily attatchable to any other intravaginal probes. And also, it was found to he practical, economic and effective for OPU with the recovery rate of 51.2%.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.263-268
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• 2001

In this paper, we present a new heuristic algorithm fur buffer allocation in FMS (Flexible Manufacturing System). It is conducted by using a genetic algorithm and simulation. First, we model the system by using a simulation software, \"Arena\". Then, we apply a genetic algorithm to achieve an optimal solution. VBA blocks, which are kinds of add-in functions in Arena, are used to connect Arena with the genetic algorithm. The system being modeled has seven workstations, one loading/unloading station, and three AGVs (Automated Guided Vehicle). Also it contains three products, which each have their own machining order and processing times. We experimented with two kinds of buffer allocation problems with a proposed heuristic algorithm, and we will suggest a simple heuristic approach based on processing times and workloads to validate our proposed algorithm. The first experiment is to find a buffer profile to achieve the maximum throughput using a finite number of buffers. The second experiment is to find the minimum number of buffers to achieve the desired throughput. End of this paper, we compare the result of a proposed algorithm with the result of a simple buffer allocation heuristic based on processing times and workloads. We show that the proposed algorithm increase the throughput by 7.2%.t by 7.2%.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.419-425
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• 2007

We have found out the relationship of nanoemulsion containing nano vitamin C, E and propolis and gingival disease. We've confirmed effect of nanoemulsion through the experiment of in vivo and in vitro. We tested cell viability of gingival fibroblast cells by MTT assay and mRNA appearance of interleukin-$1{\beta}$, using mouse that was guided inflammation. Anti-microbacterial activity for Antibacterial effect's experiment was carried out by using S.aureus and E.coli. In addition, inflammation tissue has been observed with scanning electrical microscopy. In this study, expression of interleukin-$1{\beta}$ was decreased after adding nanoemulsion containing nanovitamin C, E and propolis. We've also obtained good results from the test of Antibacterial effect against S.aureus and E.coli. Also, swelling of inflammation tissues observed by scanning electrical microscopy has gone down. In conclusion, we have gained confidence that nanoemulsion containing nano vitamin C, E and propolis has very high Antibacterial effect against bacteria in oral. And it made us guess that inflammation of gingival reduces after decreasing interleukin-$1{\beta}$. Thus, we expect that nanoemulsion containing nano vitamin C, E and propolis gives good effects to patient having gingival disease.