• Journal of Welding and Joining
• /
• 제31권5호
• /
• pp.54-58
• /
• 2013

Joint properties of vehicle ECU (Electric Control Unit) module which was manufactured by using Sn-Cu-Cr-Ca alloy were investigated. A new solder which has a middle melting temperature about $231^{\circ}C$ was fabricated as the type of 300um solder ball and paste type. The prototype modules were made by reflow process and measured spreadability, wettability shear strength and estimated interface reaction. The spreadability of the alloy was about 84% from the measurement of contact angle of the solder ball and the wetting force was measured 2mN. The average shear strength of the module which was manufactured by using the solder paste, was 1.9 $kg/mm^2$. Also, the thickness of IMC(intermetallic compound) was evaluated with various aging temperature and time in order to understand Cr effect on Sn-0.7Cu solder. $Cu_6Sn_5$ IMC was formed between Cu pad and the solder alloy and the average thickness of the $Cu_6Sn_5$ IMC was measured about 4um and it was about 50% of thickness of $Cu_6Sn_5$ IMC in Sn-0.7Cu. It is expected to have a positive effect on reliability of the solder joint.

• 마이크로전자및패키징학회지
• /
• 제16권1호
• /
• pp.7-11
• /
• 2009

본 연구에서는 electroless nickel / immersion gold (ENIG) 처리된 printed circuit board (PCB)를 무연 솔더인 Sn-3.5(wt%)Ag로 접합하였다. 리플로우 횟수를 1회부터 10회까지 다양하게 하여 리플로우 횟수가 증가함에 따른 솔더 접합부의 기계적, 전기적 특성의 변화에 대해 연구하였다. 접합부의 미세 조직 관찰을 위해 접합부 단면을 폴리싱 하여 금속간 화합물의 두께를 측정하고 종류를 분석하였다. 접합부의 기계적 특성을 평가하기 위해서 die 전단 시험을 하였는데, 리플로우 횟수가 4-5회일 때까지 전단 강도 값이 증가하다가 5회 이후로 감소하였다. 전기적 특성을 알아보기 위해 전기 저항 값을 측정하였는데, 리플로우 횟수가 증가할수록 접합부의 전기 저항 값은 점점 증가하였다.

• The Journal of Korean Physical Therapy
• /
• 제34권2호
• /
• pp.63-67
• /
• 2022

Purpose: The purpose of this study was to investigate the effect of assistance tools such as gym balls, wedges, and straps on lower extremity muscle activity and the increase in the range of motion made possible by the use of these tools. The subjects were divided into two groups: a group capable of deep-squatting (PS) and the second finding it impossible or having difficulty in performing such squats (IS). Methods: Twenty-three subjects participated in this study. Surface electromyography was used to measure the muscle activation of the rectus femoris (RF), vastus medialis (VM), and tibialis anterior (TA) muscles during deep squats, normal squats (NS), gym ball squats (GS), wedge squats (WS), and strap squats (SS). A motion analysis system was used to measure the range of motion of the knee joint during each of these exercises. Results: There was a significant difference in the RF muscle activity between the possible squat (PS) and the impossible squat (IS) groups in the GS, and there were significant differences in the RF and TA muscle activity between the groups in the WS. Both the PS group and the IS group showed a significant difference in the TA muscle activity depending on the tool used. There were also significant differences in the range of motion of the knee joints between the intervention methods using NS and those using the tools. Conclusion: In both groups, the muscle activity of the TA muscles was lower when GS, WS, and SS were performed compared to NS. In addition, compared to NS, the range of motion of the knee joint increased when the three tools were used. This study shows that the activity of the RF, VM, and TA muscles decreased and the range of motion of the knee joint increased during deep squats for both the PS and IS groups when tools were used.

• 마이크로전자및패키징학회지
• /
• 제14권4호
• /
• pp.71-77
• /
• 2007

본 연구에서는 리플로우 횟수를 달리하여 Sn-37Pb, Sn-3.5Ag와 Sn-3.5Ag-0.75Cu (all wt.%) BGA 솔더 접합부들을 OSP가 코팅된 Cu 패드 상에 형성시킨 후, 기계적 전기적 특성을 연구하였다. 주사전자현미경 분석 결과, 접합 계면에 생성된 $Cu_6Sn_5$ 금속간화합물 층의 두께는 리플로우 횟수가 증가함에 따라 증가하였다. Sn-Pb와 Sn-Ag-Cu 솔더 접합부의 경우, 3회 리플로우 후 최대 전단 강도를 나타내었으며, Sn-Ag 솔더 접합부의 경우 4회 리플로우 후 최대 전단 강도를 나타내었다. 이후 리플로우 횟수가 10회까지 증가함에 따라 전단 강도는 점차 감소하였다. 리플로우 횟수가 증가함에 따라 전기적 특성은 점차 감소하였다.

• 터널과지하공간
• /
• 제26권1호
• /
• pp.46-58
• /
• 2016

본 연구는 LIDAR라고 불리는 레이져 스캐너를 이용하여 관악산 주변 암반 불연속면을 스캔하여 얻은 삼차원 점군 데이터로부터 삼각망을 구성하고 이로부터 암반 불연속면의 방향을 검출하는 내용을 다루고 있다. 각 불연속면의 방향정보를 획득하는 데 Ball Pivoting, Wrap 알고리즘 두 가지 방법을 사용하고 점군의 샘플링 간격을 원간격, 2, 5, 10 cm로 다운샘플링 하였을 때의 방향 검출 효율성을 확인하였고 각각으로부터 얻어지는 방향정보를 퍼지 K-평균 클러스터링 기법을 이용하여 평사투영망 위에서 비교 분석하였다. 투영방향에 의존적인 Delaunay 삼각망 구성방법보다 Ball Pivoting, Wrap 알고리즘이 암반 불연속면 정보 검출에 더 적합함을 확인하였고, 샘플링 간격이 5 cm일 때 Ball Pivoting, Wrap 알고리즘 모두 가장 많은 패치를 검출해내었고 또한 가장 넓은 패치들의 면적을 검출해냄을 확인하였다.

• 대한정형도수물리치료학회지
• /
• 제24권2호
• /
• pp.75-81
• /
• 2018

Background: The purpose of this study was to investigate the effect of various relaxation techniques on various dysfunction problems caused by shortening of the sagittal muscles. Method: The subjects were 44(18 males, 26 females). The subjects were composed of 3 groups. The experimental group consisted of 14 patients with proprioceptive neuromuscular facilitation stretching (PNF) technique, control group A 15 patients with self myofacial release (SMR) ball exercise, and control group B with 15 patients with Sling exercise. After 3 weeks of relaxation on the hamstring muscle, the length of the hamstring muscle before and after the intervention was compared. Results: The results of relaxation exercise of the snake muscles applied to passive PNF group, SMR ball group, and Sling relaxation group are as follows. 1. In the passive PNF group, the muscle length of the hamstring muscle was significantly increased after the intervention. 2. The muscle length of the hamstring muscle was significantly increased after the intervention in the SMR ball group. 3. Sling relaxation group significantly increased the muscle length of the hamstring muscle after sling exercise intervention. 4. Passive PNF group showed the greatest change in muscle length before and after intervention than SMR ball group and Sling relaxation group. Conclusion: Passive PNF relaxation therapy, SMR ball relaxation therapy, and Sling relaxation therapy applied to the hamstring muscle were effective in increasing muscle length of the hamstring muscle. PNF relaxation therapy showed the most significant effect after 3 weeks intervention.

• 복식문화연구
• /
• 제29권6호
• /
• pp.779-794
• /
• 2021

In this study, the sales status of female ball-jointed dolls and their parts were investi- gated and analyzed. Baseline data from 194 products and 54 brands on domestic and international Internet sites was gathered for the manufacture of ball-jointed dolls and the development of prototype costumes for them. The results are as follows. First, the sizes used for ball-jointed dolls are SD, USD, MSD, 13SD, and 70SD together with height. This study analyzed 39 sizes (15~70cm) by classifying them into numbered groups: 1 (15~22cm), 2 (23~33cm), 3 (35~51cm), 4 (53~62cm), and 5 (63~70cm). The price varied depending on the size; for example, 50cm dolls were approximately 45,000 won, while limited editions were sold at high prices, regardless of their size. They were classified into designs according to their body proportions and facial features as follows: 7- or 8-head-figure, 5-head figure, and 3-head figure, and were presented proportionally as images of women, adolescents, and infants. Second, the head was incised so that the top could be removed horizontally or the facial region vertically, allowing attachment of the eyeballs (which were either glass, resin, or acrylic) to the inside. More than 30 different colors were sold. Various wig styles were provided, including cut, short hair, and perm. These were made from human hair, heat-resistant fiber, and artificial hair. For the hands, there was a design expressing human hand gestures. For the feet, heels were in the form of wearing either high-heels or flat soles.

• 한국지능시스템학회논문지
• /
• 제22권1호
• /
• pp.22-27
• /
• 2012

본 논문에서는 볼 나사의 구동에 의해 물체의 파지가 가능한 로봇 그리퍼 메커니즘을 제시한 후, 시뮬레이션을 통하여 제시한 그리퍼 메커니즘의 파지 동작에서 나타날 수 있는 기구학적인 특성을 분석한다. 이를 위하여 구동기의 관절 공간과 그리퍼의 끝 공간간의 기구학적 관계를 파악한다. 제안한 로봇 그리퍼는 하나의 구동모터를 사용하고, 좌우 대칭인 폐체인(closed-chain)을 형성하고 있는 것이 특징이다. 결과적으로, 제안한 로봇 그리퍼는 구조적으로 외력에 강인하고, 하나의 구동모터에 의해 파지 동작이 구현되므로 수월한 파지가 가능하다. 또한 제안된 그리퍼는 파워 파지에 유용한 조임 효과를 갖는다.

• 복식문화연구
• /
• 제32권1호
• /
• pp.58-69
• /
• 2024

The purpose of this study was to develop the Functional golf inner-wear by preventing the injuries and enhancing the performance of the Golf swing by checking the influence of the wearing of the functional golf inner-wear considering golf characteristics on the Swing trajectory and Shot distance. Functional inner-wear effective for golf swing was manufactured using the sports taping method. Changes in driver and iron swing before and after wearing the functional golf inner-wear manufactured in this way were measured using trackman equipment. Measurement variables were limited to Club Speed, Attack Angle, Club Path, Ball Speed, Smash Factor, and Priority. Before and after wearing functional golf inner-wear, there were statistically significant differences in driver club speed, iron club speed, driver etch angle, iron club pass, driver ball speed, driver smash factor, iron smash factor, driver carry, iron carry, and right shoulder joint proprioceptive sensory ability. As a result, functional golf inner-wear is effective for ball speed, impact, and carry by increasing club speed and efficient swing. Future research will focus on the development of functional golf that can improve the swing ability in a short game that plays an important role in the golf game through various sports taping grafting technique, textile, special material, film, Research on functional golf inner-wear.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.15-18
• /
• 2000

We developed a human-sized BWR(biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. The robot overcomes the limit of the driving torque of conventional BWRs. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. The BWR was developed to walk autonomously such that it is actuated by small torque motors and is boarded with DC battery and controllers. In the performance test, the BWR performed nice motions of sitting-up and sitting-down. Through the test, we could find capability of high performance in biped-walking.