• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.366-367
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• 2019

산업기술의 정밀화, 자동화가 진행됨에 따라 로봇 산업이 발달하게 되고, 로봇에 주로 사용하는 DC 모터 제어의 성능이 더욱 중요해지고 있다. 로봇에 적용되는 소용량 DC 모터의 경우, 전기자 권선의 인덕턴스가 작고 조항이 상대적으로 크다. 저항이 상대적으로 큰 DC 모터의 경우 저항에 흐르는 전류에 의한 전압 강하 성분이 속도에 비례하는 역기전력(Back-EMF)에 비해 무시할 수 없고, PWM 전압에 의한 전류맥동이 커서 평균전류 샘플링이 어렵다. 본 논문에서는 DC 모터의 전기적 모델을 기반으로 속도 제어기의 출력 전압을 결정하는 방법을 제안하였다. 핸드 로봇에 제안된 방법을 적용하여 속도 제어기의 특성을 확인하였다.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.2
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• pp.257-266
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• 1998

This study was conducted to examine the changes of the mechanical properties of the position in jean slacks during the wear, previously used for the wearing test, which were subjected to repeated tensile-shearing deformation using a simulated fatigue tester has been investigated and compared, by calculating both mechanical properties and hand value(HV) of these fabrics with KES-F system and the by obtaining the THV through these calculated properties. The results are as follows. 1. The fatigue phenomenon of mechanical properties was the LT, 2H B, 2HBS, MMD, SMD, RC values increased, elasticity values of tensile, bending and shearing properties, such as B, G and compression properties LC, WC were reduced. It was shown, then, that those fabrics lost their elasticity and became flexible and soft with the increase of fatigue. 2. The hand value and THV; except anterior knee from all part of KOSHI, NUMERI, FUKURAMI was decreased. 3. The fatigue phenomenon of hand value was different on the position of clothing; on the position of hip, rate of B, G smaller than other parts and KOSHI was decreased, on the part of anterior thigh was FUKURAMI was increased, on the anterior knee RC, NUMERI, THV was increased, on the posterior knee was 2HB, 2HG, 2HGS showed increasedgreater than any other part and on the hem of back, MMD was increased, but NUMERI was decreased. 4. The changing process of mechanical properties in the simulation testing by the fatigue tester has similar tendency to that of the wearing tester. It is concluded that this testing method is useful to predict the fatigue phenomena of fabrics caused by wearing.

• Korean Journal of Community Nutrition
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• v.7 no.5
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• pp.603-614
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• 2002

In this study, the nutrient intakes, dietary quality, and muscle strength of elderly women in a social-welfare center of a large city were compared with those of elderly women at home in a large city. Also, the relationships between muscle strength and nutrient intake status were investigated in both elderly group. The results of this study were as follows: The ages of elderly in the social welfare center and of elderly in general home residing elderly were 68.2 and 70.3 years, respectively. The average energy and nutrient intakes of both groups were lower than the Korean RDA. There were no differences between the groups in terms of macro-nutrient composition and quantity. The elderly in center showed significantly lower intakes of vitamin $B_2$, niacin and calcium than the home-residing elderly. The hand grip strength and back muscle strength were lower in the elderly of social welfare center, but a significant difference was found only in the left hand grip strength. The muscle strength, especially the left hand grip strength of those in social welfare center, showed significant correlations with various nutrient intakes. In contrast, generally no relationship between muscle strength and nutrients intakes status could be found in the home residing elderly. The variances in the mean hand grip strength and the left hand grip strength 19.0% and 18.6% respectively, were explained by their ages. This is in contrast to 22.3% and 32.4% of calorie intake and vegetable protein intake in the elderly of the social welfare center. In conclusion, the status of nutrient intake in those in the social welfare center seems to be low, and it is assumed that the low calorie and vegetable protein intake may contribute to the muscle strength decline in the socioeconomically high risk elderly.

• Journal of Korean Medical classics
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• v.20 no.2
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• pp.137-145
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• 2007

Pulse diagnosis that distinguishes internal injury from external injury by comparing the left and right of the chon pulse was formed in the process of Naegyoung's pulsation theory of ST9 and LU9 being assimilated into diagnostic method by taking chon pulse. The founder of school of internal injury, I Dong-won, expanded the horizon for this method to be widely used in clinical practice by especially explaining the specific application and theoretical background. According to him, pulse at ST9 which means chon pulse at the left hand, is bigger than the chon pulse at the right hand, it reflects external injury. Bigger "entrance pulse", a chon pulse at the right hand means internal injury. The reason is the left side of the body is a path for Yanggi so it controls the exterior part and the right side of the body is a path for Eumgi to descend so it controls the interior part. Internal injury develops as the spleen and stomach get injured. If the spleen and stomach is damaged essence derived from food cannot ascend to the stomach and will flow back to the lower part. As a result, fire of Eum type formed at the lower part will shoot up to the upper part and manifests external injury-like exterior syndromes. In this case, evidence distinguishing between internal and external injury is the fact that right hand pulse is bigger than the left hand. The important reason for distinguishing between internal and external injury is because when treating external injury caused by excess syndrome, pathogenic Gi should be dispelled. However, treating internal injury cased by deficiency syndrome, requires promoting the primordial Gi.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.4
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• pp.159-169
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• 2010

Objectives : This study was designed to evaluate the correlation of the cross-sectional areas(CSA) of paraspinalis(iliocostalis lumborum, multifidus, longissimus thoracis parts lumborum) and psoas muscle and sex, age, change of the VAS(visual analogue scale) and past history of chronic low back pain in patients suffering from HIVD(herniation of intervertebral disc). Methods : Medical records of 140 subjects with HIVD were retrospectively reviewed. The MRI(magnetic resonance imaging) findings on the patients were scanned and analyzed by PiView program to find the paraspinal and psoas muscle CSA and were evaluated by the correlation of sex, age, change of the VAS, and past history of chronic low back pain. Results : There was significant difference between groups in male and female, young-adults age and middle age, middle age and old age, young-adults age and old age. But the correlation of the paraspinal and psoas muscle CSA and past history of chronic low back pain were partially significant. On the other hand, the correlation of the paraspinal and psoas muscle CSA and change of the VAS were not significant. Conclusions : These results suggest that the cross-sectional areas(CSA) of paraspinalis and psoas muscle have relevance to sex and age.

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.67-74
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• 2017

Objective : The purpose of this study was to investigate the prevalence of and the relevant risk factors for lumbar spondylosis (LS) among middle-aged and elderly rural Korean residents and to explore the association between radiographic LS and lower back pain (LBP) in relation to age and gender. Methods : This community-based, cross-sectional study evaluated 1512 subjects with available radiograph. The prevalence of LBP was obtained using a questionnaire and disability resulting from LBP was measured using a validated Korean version of the Oswestry disability index (ODI). In lumbar spine radiographs, vertebral levels from L1/2 to L4/5 were evaluated for the presence of osteophytes and joint-space narrowing (JSN), and Kellgren-Lawrence (KL) grading was applied. Results : Of 4261 subjects aged 40-79 years, data from 1512 subjects were included. The prevalence of radiographic LS indicated by grade ${\geq}2$ osteophytes and JSN were 53.9 and 15.8%, respectively. Seventy-three percent of subjects had KL grade ${\geq}2$ spondylosis and LBP was present in 36.5% of subjects. Although LS was more common among males, the prevalence of LBP was higher among females. Age, male gender and history of hand or knee arthritis were risk factors for LS. LS was significantly associated with LBP mostly among females over 60 years old and correlated with the ODI after adjusting for age and gender. Conclusion : Our study among rural Korean residents revealed a high prevalence of LS and LBP. The association between LS and LBP was observed mostly among females and LS was significantly correlated with the severity of back pain.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.5-13
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• 2003

The soil nailing is one of the useful support-system in urban excavation because of the presence of other structures in the vicinity Since the soil nailing system was introduced, model experiments and theoretical studies have been performed to investigate behavior of soil nailed wall. However, there are few data in the case of multi-layered soil strata just like Seoul Metropolitan area in Korea. The feed back analyses are carried out using the measured wall displacement data for soil nailing construction sites with multi-layered strata in order to analyze the distance and the coefficients of extension zone of ground behind soil nailed wall. As a result, the distance of extension zone increased with increasing of the final excavation depth and the ratio of the distance to the final excavation depth was shown to be about 94% of the final excavation depth. Also, the coefficients of extension zone increased with enlargement of soil layer thickness and converged into constant value of 1.05. On the other hand, the maximum vertical displacements by the feed back analysis and Caspe's method were shown to be approximately 80%, 150~280% of the maximum horizontal displacement respectively.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.3
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• pp.29-37
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• 2019

PURPOSE: Prone hip extension (PHE) has been used for assessment of lumbo-pelvic movement and strengthening exercise for weakness of the hip joint muscles in patients with chronic low back pain (CLBP). On the other hand, few studies have examined which are the best PHE exercises to activate the gluteus maximus (GM) selectively in physical therapy practice. To aim of this study compared the muscle activity of the GM, rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA) during these four different prone hip extensions, PHE, PHE with quadriceps activation (PHEQA), PHE with ankle dorsiflexion (PHEAD), and PHE with ankle plantarflexion (PHEAP), in subjects with CLBP. METHODS: Nineteen subjects with low back pain participated in this study. Subject performed four PHE exercises and surface electromyography (EMG) was used to evaluate the muscle activity. Data were analyzed by one-way repeated-measures analysis of variance (${\alpha}=.05/3=.017$) and a Bonferroni adjustment was performed if a significant difference was found. RESULTS: The muscle activities recorded by EMG showed significant among the four exercises. The muscle activity of the GM increased significantly during PHEQA than during PHEAP (P=.012). CONCLUSION: PHEQA is the most effective exercise for eliciting greater GM muscle activation among the four PHE exercises in subjects with CLBP.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1584-1590
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• 2017

This paper presents a implementation method of reliable speed limitation controller considering motor parameter variation in high speed operation. In spinning process of drum washing machine, speed increase has to be limited when unallowable imbalance mass is detected. Otherwise, severe noise and vibration can happen because noise and vibration are proportional to imbalance mass. To detect imbalance mass, d-axis current magnitude is used. However, we have to compensate for back-emf and power supply variation by means of detecting them because d-axis current is affected by both of them. On the other hand, we have to carefully estimate back-emf because back-emf is affected by stator resistance variation and inverter voltage error. Stator resistance variation can happen by manufacturing process for mass production or temperature variation in running. And there are inverter voltage errors between command voltage from micro-computer to inverter and real voltage from inverter to motor because of rising and falling time delay and turn-on resistance of power semiconductor switch. To solve this problem, we propose 2-step align current injection method which is to inject step-wise current right before starting. By this method, we can simply obtain stator resistance by ratio of voltage without inverter voltage error and current, and we can measure inverter voltage error. So we can obtain more exact model current, and then by simple calculation with compensation gain, we can estimate more accurate motor back-emf. We show that this method works well. It is verified through experiments.

• Journal of Korean Clinical Nursing Research
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• v.14 no.1
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• pp.15-23
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• 2008

Purpose: The purpose of this study was to examine the effect of absolute bed rest(ABR) on occurrence of bleeding, discomfort and back pain after kidney biopsy. Method: This study was the nonequivalent control group posttest design. The experimental group was allowed to stay in beds for 18 hour-bed rest(BR) after 6 hour-ABR while the control group was allowed to stay ABR for 24 hours. Results: No bleeding sign was showed for all the patients. Discomfort of voiding, eating, ABR in the control group appeared at a higher level. Three subjects in the control group needed nelaton catheterization, whereas no catheterization was required in the experimental group. There was no significant difference in back pain. However, the control group used more pain killer with significant difference. From these results. Conclusion: There was no significant correlation between ABR time and bleeding. On the other hand, the discomfort of the experimental group appeared at a lower level by reducing ABR time. Therefore, Reduction of ABR time after kidney biopsy would be more efficient way for patients.