• Journal of Electrical Engineering and Technology
• /
• 제11권4호
• /
• pp.889-897
• /
• 2016

This paper presents an improved approach for compensating rotor position signal displacement in brushless DC (BLDC) motors with misaligned hall-effect sensors. Typically, the hall-effect sensors in BLDC motors are located in each phase and positioned exactly 120 electrical degrees apart. However, limitations in mechanical tolerances make it difficult to place hall-effect sensors at the correct location. In this paper, a position error compensator to counteract the hall-effect sensor positioning error is proposed. The proposed position error compensator uses least squares error analysis to adjust the relative position error and back-EMF information to reduce the absolute offset error. The effectiveness of the proposed approach is verified through several experiments.

• 대한치과교정학회지
• /
• 제30권2호
• /
• pp.127-142
• /
• 2000

임상에서 다양하게 사용되는 Multiloop Edgewise Arch Wire(MEAW)는 구치부 치아의 치축 직립을 위해 II급 고무줄이나 수직고무줄과 함께 사용된다. 이때 tip back bend의 정도는 각 환자의 구치치축의 근심경사의 정도에 따라 가감이 결정되나 이 장치가 실제 치근막에서 어떤 효과를 나타내는지 정확히 알려진 바는 없다. 이에 저자는 MEAW의 역학적 효과를 알아보기 위해 tip back bend의 정도를 변화시킨 후 II급 고무줄, 수직고무줄을 적용시켜 유한요소법을 통해 치근막에서 발생되는 응력의 분포와 크기를 정량적으로 비교, 관찰하여 장치의 역계를 이해하고 치료효과를 예측해 보고자 실험을 고안하였다. 발치나 교정치료의 경험이 없는 25세 남자 정상교합자를 대상으로 컴퓨터 단층촬영을 시행하여 얻은 방사선필림을 기초로 하여 유한요소 상악치아모델과, 치근막모델을 제작하였으며 여기에 beam element로 제작된 MEAW의 tip back bend를 5도, 10도, 15도로 달리하여 II급 고무줄 및 수직고무줄을 적용시켜 각 치근막에서의 압축, 인장력의 분포와 응력의 크기를 상호 비교한 결과 다음과 같은 결론을 얻었다. 1. MEAW에 tip back bend를 5도, 10도, 15도로 부여하고 II급 고무줄이나 수직고무줄을 적용시켰을때 전체 치근막에 나타나는 압축, 인장의 분포는 II급 고무줄, 수직고무줄 각각의 경우에서 tip back bend의 정도에 상관없이 유사한 양상을 나타냈다. 2. 각 치아의 치근막에 나타난 압축, 인장력의 크기는 5도,10도의 경우보다 15도 tip back bend 부여시 더 크게 나타났다. 3. 제1, 2대구치 원심측 치근막에서는 압축력이 나타났으며 특히 제2대구치 치근막의 압축부위가 제1대구치 치근막 압축부위보다 더 넓고 압축력의 크기도 더 크게 나타났다. 또한 tip back bend 정도가 클수록 압축력도 크고 압축부위도 더 넓게 나타났다. 4. 대구치 치근막의 압축력은 소구치 치근막의 압축력보다 상대적으로 더 작게 나타났다. 5. II급고무줄과 수직고무줄 적용 시를 비교해 보면 수직고무줄 장착시 전치부 치근막에 인장력이 더 넓게, 그 크기는 더 작게 나타났다. 반면에 구치부 치근막에 나타나는 응력의 분포와 크기는 별 차이를 보이지 않았다. 5. 전치부 치근막 인장부위에서 인장력은 견치에서 제일 컸다.

• 한국안광학회지
• /
• 제8권2호
• /
• pp.57-63
• /
• 2003

본 연구에서는 안경렌즈의 전면굴절력, 굴절률, 그리고 중심 두께의 변화에 따라 상측정점초점면에 맺는 착락원 직경 변화를 조사하기 위해 Code V와 LOSA 2.0 프로그램을 사용하였으며, 상측정점굴절력이 -4.00D이고 직경이 70 mm인 근시교정용 안경렌즈를 고려하였다. 또한 안경렌즈의 전면 굴절력은 0~10D, 중심 두께는 1.1~2.0mm 그리고 굴절률은 $n_d$ = 1.498, 1.523, 1.586, 1.60인 경우를 각각 고려하였다. 안경렌즈의 전면굴절력이 증가할수록 상측정점초점면에서 맺는 착락원 직경의 크기는 급격하게 증가하였다. 또한 안경렌즈의 굴절률이 증가한 경우에 상측정점초평면에 맺는 착락원 직경의 크기는 감소하였으며, 전면굴절력의 변화에 따른 착락원 직경의 크기 변화는 작았다. 안경렌즈의 중심 두께가 증가할수록 상측정점초평면에 맺는 착락원 직경 크기에는 거의 영향이 없지만 안경렌즈의 가장자리의 두께는 증가하였다. 이러한 결과로부터 구면렌즈의 경우에는 전면굴절력이 작고, 굴절률이 클수록 상측정점초평면에서 더 좋은 결상을 하고 있음을 알 수 있다.

• 대한의료기공학회지
• /
• 제18권1호
• /
• pp.1-26
• /
• 2018

The objective of this study is to verify the effects of Moosim-Gi-Gong Doinbeop on low back pain targeting low back pain patients hospitalized in Korean medicine hospitals. For the study, 44 adult female and male patients hospitalized with low back pain at M Korean Medicine Hospital and H Korean Medicine Hospital located in Gimpo, Gyeonggi Province were recruited. The subjects had a temperature difference between left and right 湧泉(KI1) of over 0.5℃ through infrared thermographic imaging, and 23 of them were classified in the control group for retrospective analysis based on the test records. Infrared thermographic imaging, X-ray pelvic AP view - standing position, a sit-and-reach test and a VAS survey were employed for detection, and IBM SPSS Statistics 24 for the statistical process. The results were rounded down to three decimal places as in an average±standard deviation, and the significance level was 0.05 to be evaluated significant if p<0.05. The result of the study is as follows: 1. In the comparison between before and after conducting Moosim-Gi-Gong Doinbeop, the meaningful difference was shown in the experimental group in all indicators. But Indicators except for the temperature difference between right and left 湧泉(KI1)(difference between before and after) and In displaced pelvic correction indicators on the X-ray showed a significant difference in the control group. 2. As for the variation widths of the experimental group and the control group, the former showed significant temperature differences between 印堂(EX-HN3) and 關元(CV4) and right and left 湧泉(KI1); difference variations of anteflexion; and changes in PI and In displacement on the X-ray. 3. As for changes in the experimental group according to demographic characteristics, gender, age and degree of obesity did not show significant differences in all indicators. However, those who experienced back pain for more than six months in the experimental group showed the biggest body temperature differences between 印堂(EX-HN3) and 關元(CV4), while other indicators had no significant difference. As a result, patients who received Korean medicine treatment showed relieved back pain and improvement in pelvic correction and sports activity; however, those who got Moosim-Gi-Gong Doinbeop together showed more clearer improvement effects in pelvic correction and sports activity.

• The Journal of Korean Physical Therapy
• /
• 제25권5호
• /
• pp.282-287
• /
• 2013

Purpose: The purpose of this study was to investigate the characteristics of patients with Chronic Low Back Pain (CLBP) in disability, pain, and cognition, and to compare those characteristics to the ICF concept analyzing the association between World Health Organization Disability Assessment Schedule 2.0: 12 item-interviewer version (WHODAS 2.0) and those of scales i.e. Oswestry Disability Index (ODI), the Short-Form McGill Pain Questionnaire (SFMPQ), and the Fear avoidance & belief questionnaire (FABQ). Methods: A total of 91 patients with CLBP were invited to participate in the study. Physical therapists interviewed all participants using SFMPQ, FABQ, ODI, and WHODAS 2.0 for collection of information on pain, cognition, and functional level data. Subjects scored their disability, pain, and cognition related to LBP using WHODAS 2.0, ODI, SFMPQ, and FABQ. Data analysis was performed using the Spearman correlation coefficient. Results: A positive relationship was observed between WHODAS 2.0 and each scale indicating that lower back specific disability components could be related to the ICF concept in ODI (r=0.77). Pain intensity and pain oriented movement were found to be related to general functioning in patients with CLBP (r=0.52, r=0.55, respectively). Conclusion: It can be suggested that the specific disability scale for LBP, ODI can be related to the ICF concept, WHODAS 2.0, and it may be a useful measure for patients with CLBP.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제33권4호
• /
• pp.319-322
• /
• 2011

Purpose: The purpose of this study was to examine the appropriate degree of set-back of the mandible by evaluating the rate of relapse after surgery. Methods: Among the patients who visited our hospital from January 2002 to January 2007 and who underwent orthognathic surgery, of the patients available for follow-up observation, the rate of relapse after surgery was investigated according to the set-back degree. The patients were divided into groups by the degree of set-back, and relapse was evaluated by the radiographs performed the day after surgery, 6 months after surgery, 1 year after surgery, 2 years after surgery and 3 years after surgery. Results: In cases that exceeded the limit of posterior movement of the mandible (13 mm) or that had the wrong position of the condyle, a greater tendency toward relapse was shown. Conclusion: Based on the results of this study, among the cases that required a large amount of posterior movement of the mandible, two jaw surgeries accompanied by bilateral sagittal split ramus osteotomy (BSSRO) and LeFort I osteotomy are recommended.

• 기본간호학회지
• /
• 제10권1호
• /
• pp.30-36
• /
• 2003

Purpose: The strength of hand grip, low back muscles and knee joint muscles were measured and then compared to the bone mineral density (BMD) of each forearm bones (including ulna and radius), lumbar spine, and femur in young women in order to identify the relationship between muscle strength and bone mineral density. Method: The BMD was measured with a Dual Energy X-ray Absorptiometry and muscle strength was measured with a handgrip dynamometer and a Cybex Norm. Data were analyzed with frequencies, percentages, means, and Pearson correlation coefficients. Result: 1) Higher grip strength correlated positively with higher BMD in the forearm (r=.246, p=.007), higher low back extensor strength with higher BMD in the femur (neck, trochanter and Ward's triangle)($r=.323{\sim}.226$, $p=.003{\sim}.043$) and higher strength in the knee joint extensor with higher BMD in the lumbar spine (r=.227, p=.041), femur neck, and femur trochanter significantly ($r=.295{\sim}.226$, $p=.007{\sim}.043$). There was no significant correlation between the strength of low back extensors and BMD in the lumbar spine, now with strength of knee joint flexor and the BMD in the femur. 2) The muscle strength of each part of the body had significant positive correlations to each other part ($r=.255{\sim}.728$ $p=.021{\sim}.000$) Conclusion: The results of this study showed that with the development of a muscle there was an increased BMD of the corresponding part, and the BMD of each part was influenced by adjacent muscles. To promote the health of bones, it is important to strengthen the muscles of related bones, based on balanced development of all muscles.

• 한국의류산업학회지
• /
• 제13권1호
• /
• pp.82-90
• /
• 2011

This study examines if men in the 20's and 30's have different preference for bag types according to their age and gender-role identity types in order to provide foundational data for the male bag market to segment its customers and establish marketing strategies. Total 288 questionnaire sheets were distributed to 186 men in the 20's and 102 men in the 30's residing in Busan. First, according to the result of analyzing their preference for bag types, adult men in the 20's and 30's preferred cross bags the most. It was also shown that men who are feminine or androgynous prefer back packs, shoulder bags, and tote bags to the other two types. Second, about cross bags, men in the 20's showed a higher rate of having two or three than those in the 30's. Men in the 20's possessed back packs more than those in the 30's. And men tend to show a lower rate of having shoulder bags compared with that of cross bags or back packs. Men in the 30's possessed briefcases more than those in the 20's. Masculine men had more briefcases than the other types of bags, and androgynous men tend to have more tote bags than the other types of bags. Third, men in the 20's and 30's all deemed that back packs go well with the casual style. Men in the 20's regarded shoulder bags are the type of bags that harmoniously matches all styles including casual or semi-suit; however, men in the 30's think they only suit casual or semi-suit. And it was also found that men in the 20's think briefcases are the type of bags that goes well with various styles of clothes while men in the 20's consider they are the type of bags only matching suits.

• 척추신경추나의학회지
• /
• 제8권2호
• /
• pp.131-139
• /
• 2013

Objectives : The purpose of this study is to investigate the efficacy of conservative treatment on Achondroplasia patient who has low back pain with radiation. Methods : The patient was treated by conservative treatment including acupuncture, pharmaco acupuncture, chu-na manipulation, herbal medicine. Numeric rating scale(NRS), Oswestry disability index(ODI) were used to evaluate pain reduction. Physical examination also used to compare with admission state and discharge state. Results : After 1 month admission treatment, NRS decreased 9 to 6, ODI dcreased 56 to 42, ROM improved as normal person. Conclusions : It was efficient that Achondroplasia patient who has low back pain with radiation treated as conservative treatment including acupuncture, pharmaco acupuncture, chu-na manipulation, herbal medicine. But It was just one case and treatments were carried out in Integrative Package. So further studies are required to compare that which treatment is efficient.

• 대한전자공학회논문지TC
• /
• 제49권4호
• /
• pp.47-52
• /
• 2012

본 논문에서는 200 GHz 대역의 시스템에 응용이 가능한 구형도파관 전송선로와 평면 구조인 마이크로스트립 전송선로 구조의 부품들의 상호 신호전달을 위해 프로브 구조의 변환기를 설계하였다. 설계된 변환기는 프로브, 임피던스 변화를 위한 테이퍼구조와 마이크로스트립 구조의 전송선로로 구성된다. Ansoft사의 HFSS 시뮬레이션 툴을 이용하여 프로브의 크기 및 테이퍼의 길이를 변경하여 주파수 특성 변화를 확인하였으며 최적화하였다. 변환기는 특성 검증을 위해 back-to-back 구조로 설계되었으며, 시뮬레이션 결과 186 GHz ~ 210 GHz의 대역폭을 갖으며 전 대역에서 - 0.81 dB 이하의 삽입손실과 -10 dB 이상의 반사손실을 확인하였다.