• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.360-368
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• 2010

Noise and vibration triggered by pile driving in a construction site not only give hard time to the surrounding areas but could also cause residents nearby to file civil complaints to the extent of bringing construction to a halt. To deal with this issue, construction engineers have worked strenuously to develop low noise & low vibration pile methods. A noise & vibration-free screw concrete pile method proposed in this study is one of the successful outputs. It penetrates pile underground by rotating and pressing in body of the pile to avert noise and vibration while maximizing bearing capacity. A prototype of noise and vibration-free precast screw pile method was manufactured, which is not seen anywhere in Korea and elsewhere, and have undergone pilot tests twice to determine construction method.

• 한국세라믹학회지
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• 제33권11호
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• pp.1285-1291
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• 1996

Using Cr2O3 Al and graphite powders as starting materials Cr3C2 was synthesized by combustion synthesis process according to the following reaction : 3Cr3C2 +4C+6Allongrightarrow2Cr3C2 +3Al2O3. The synthesis was conducted at 2 atm in an argon atmosphere. in this study main-product was monolithic phase of Cr3C2 /Cr7C3 mixture and sub-product was slag state of $\alpha$-Al2O3. Single phase of Cr3C2 was obtained when crushed main-product was heat-treated at 120$0^{\circ}C$ for 3h in vacuum state with addition of 2.5wt% C. The obtained Cr3C2 powder can be used as plasma-arc deposit material because the flowability index of powder with the size of 9-50${\mu}{\textrm}{m}$ was 66.

• 한국정밀공학회지
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• 제30권9호
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• pp.915-921
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• 2013

Most of large scale solar panel handling robots adopt the timing-belt drive system for its driveline because of the simplicity and the easiness of implementation. The vibration caused by the flexure of the timing belt would increase as the size and the weight of the panel that the robot handles increase and the vibration would deteriorate the precision and/or productivity of the whole robot system. For the development of a proper control system and for the improvement of the design of the robot it is important to estimate the oscillatory response of the robot system including the flexible drive system properly. In this paper a flexible multi-body dynamics model of a large-scale solar-panel-handling robot with the flexible timing-belt drive system is developed using a generic multi-body dynamics analysis program, RecurDyn.

• 한국응급구조학회지
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• 제22권2호
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• pp.93-102
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• 2018

Purpose: The study aims to establish an effective training strategy and methods by comparing the effects of educational interest, satisfaction, and achievements of virtual reality and videos education before simulation training. Methods: The randomized control study was implemented on May 31, 2018, by randomly selecting 36 participants to compare educational virtual reality and videos. Statistical analyses were performed using SPSS 20.0. Results: The participants were divided into an intervention group of 17(47.2%) and a control group of 19(52.8%). Regarding the levels of satisfaction, a significant difference (p= .010) was noted between the control (3.88 points) and the intervention groups (4.45 points). A significant difference (p= .001) was also noted between the intervention (80.3 points) and control (63.3 points) in terms of total simulation practical skills. Conclusion: Educational virtual reality can be an alternative training method to achieve the standard educational objectives by raising levels of educational interest and of achievement with practical skills.

• 자원환경지질
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• 제33권5호
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• pp.435-442
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• 2000

Although the mummies of Lee Myeong-Jung and his wife who were a member of the Moon family, were buried in similar sites in around 1560, the degree of decay of the dead bodies and antiquities between two people were quite different. This study was focused on the cause of-those differences in terms of engineering geology. Cranular soil found several metered depth around the study site has good drainage ability and such characteristic could be a factor of excellent conservation of dead body. From the physical characteristics of the lime-containing material that is considered to be a barrier from water and air, it was observed that the material around dead body of wife was more compact and denser than that of husband. Such results could be a clear evidence that the lime containing material around dead body of wife was excellent barrier for keeping away from water and air. To investigate those differences of physical characteristics and constituent materials between two lime-containing materials, minerals had to be identified from the two materials. It was revealed that lime-containing material around dead body of wife contains gypsum and more calcite, which could be the reason for better barrier preventing from water and air than those around husband.

• 응용통계연구
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• 제26권3호
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• pp.421-429
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• 2013

현대통계학은 많은 분야에서 사용되고 있으나 사용자들이 통계학적 개념을 이해하는데 어려움을 겪고 있다. 한편으로는 초등학생 때부터 줄기잎 그림이나, 비율자료의 원그림 등은 물론이고 평균과 같은 기술통계를 배우고 있다. 초등학교 고학년이나 중학교 저학년 학생들을 위한 직관적인 통계 패키지가 있다면 미래의 통계 사용자들인 이들 학생들이 통계적 개념을 이해하는데 많은 도움이 될 것이라고 생각하여 직관에 기초한 통계 패키지를 개발하였다.

• 대한후두음성언어의학회지
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• 제14권1호
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• pp.10-15
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• 2003

Background and Objectives : Ankyloglossia, commonly known as tongue-tie, is the result of a short, fibrous lingual frenulum or highly attached geioglossus muscle. This condition may cause sucking and swallowing problems, articulation disorders, interference with the tongue's cleansing action, increased the potential for caries, and inability to lick the lips, play a wind instrument, and 'french kiss' Treatment is surgical procedure. In the most cases, horizontal sectioning and mucosal suture(the conventional procedure) is preferred, but in some cases, the Z-plastic procedure is effective. This study is aimed to compare the result of the two procedures. Materials and Methods : Twenty tongue-tie patients underwent operation. Ten patients were treated with the Z-plastic procedure and ten patients were treated with the conventional method randomly. We checked preoperative mobile tongue length, postoperative mobile tongue length, operation time and postoperative wound states. Results : Among the 20 cases of tongue-tie, 2 cases are excepted due to pre-operative state, thus we compared 18 cases of tongue-tie patients. There is no statistically significant difference between the two procedures except in operation time. The Z-plastic procedure apparently needs a little more operating time. Conclusion : Patients treated with the Z-plastic procedures appeared to have better outcomes, but the data shows no statistical significance except in operating time. Consequently, the Z-plastic procedure is indicated in a limited amount of cases.

• 한국자동차공학회논문집
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• 제15권4호
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• pp.115-123
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• 2007

In this paper, an analytical model is developed to describe the dynamic characteristics of a roller bearing. In order to obtain accurate dynamic response of roller bearing, each roller is modeled as a rigid body, which has radial and axial movement and rotational constraints. Beam element between outer race segments is used to consider flexibility of outer race. Beam deflection is calculated from beam forces and used for contact between roller and outer race. The efficient contact search kinematics and algorithms in the context of the compliance contact model are implemented to detect the interactions between roller and race for the sake of speedy and robust solutions. The numerical results are validated with another analysis results which are calculated using waviness condition. Increasing rollers, dynamic responses are compared with each other. In order to confirm dynamic behavior and nonlinear characteristic of roller bearing, Poincare map is used.

• Applied Microscopy
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• 제40권1호
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• pp.37-45
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• 2010

포획된 야생의 우수리땃쥐 Crocidura lasiura는 구치의 마모와 높이를 이용하여 3개의 연령군으로 분류하였고 번식과 생식기관의 계절적 변이를 조사하였다. 유수들은 구치에서 마모를 가지지 않았고 세 번째 구치 높이가 첫 번째와 두 번째 구치보다 낮았고 비번식상태만을 가졌다. 아성수들은 약간의 마모를 가졌고 세 번째 구치가 첫 번째와 두 번째 구치 높이에 도달했고 성수들은 구치에 깊은 마모를 가졌으며 아성수와 성수는 계절에 따라 번식 혹은 비번식상태를 가졌다. 조직학적 관찰을 근거로 아성수와 성수 수컷의 번식상태는 2월 초에서 10월 초까지 유지되었고 4월에 가장 높은 번식활동을 보였으며 암컷의 번식 상태는 3월 말에서 10월까지 유지되어, 수컷이 암컷보다 빨리 성적 성숙에 이르는 것으로 밝혀졌다. 반면 번식상태는 비번식기 동안 중단되며 이것은 식량자원인 토양 무척추동물의 부족때문이라 생각된다. 번식기의 아성수와 성수들은 많은 생식세포들로 채워진 확장된 세정관을 가지는 큰 정소와 많은 정자들을 가진 팽창된 부정소 미부를 가졌고 10.0 g 이상의 몸무게와 0.03 g 이상의 정소와 부정소 무게를 가졌다. 번식기의 암컷들은 4~6개의 새끼를 가진 임신상태이거나 난소에 성숙난포들과 황체를 가졌고 9.6 g 이상의 몸무게를 가졌다.

• 한국의상디자인학회지
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• 제19권4호
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• pp.93-104
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• 2017

This study is a basic study to develop shoe last design technology to enhance and revitalize the competitiveness of the handmade shoes. In-depth interviews were conducted with four manufacturers in Seongsu-dong to identify the production status and design technology of shoe lasts. The result of the research is as follows. Firstly, shoe lasts for adults are produced at intervals of 5mm between 245mm-285mm for men's shoes, and between 220-260mm for women's shoes. The production rate of women's shoes was high in the order of general type, boot type, and sandal type while men's shoes mainly produce general type. Secondly, the master last size and ball girth rating for men's and women's shoes were analyzed to EE-EEE grade at 260mm and D grade at 235mm. The length of the master last for men's shoes is 276-290mm, the heel width is 60-65mm, the ball width is 88-90mm, the ball girth is 250mm, and the waist girth is 248mm. The length of the master shoe last for women's shoes is 236-245 mm, the heel width is 50-55mm, the ball width is 78-80mm, the ball girth is 211~213mm, and the waist girth is 213~215mm. Thirdly, the last grading deviation is 5mm in length, the heel width is 0.5mm, the ball girth is 3.5mm, and the ball with is 1.2mm. The ball girth dimensions of Oxford type, slip-on type, and sneakers type are made at 250mm, 248mm, and 245mm for men's shoes. For women's shoes, the ball girth dimensions of pump type, loafer & boot type, and sandal type are made at 211~213mm, 214~215mm, and 211mm. Fourthly, t+he construction of the automation system is insufficient and almost completely depends on manual production.