• 전기학회논문지P
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• 제64권2호
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• pp.67-73
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• 2015

Distance relay is widely used for the protection of long transmission line. Most of distance relay used to calculate line impedance by measuring voltage and current using DFT. So if there is a computation error due to the influence of phasor by DC offset component, due to excessive vibration by measuring line impedance, overreach or underreach can be occurs, and then abnormal and non-operation of distance relay can be issue. It is very important to implement the robust distance relaying that is not affected by DC offset component. This paper describes an enhanced distance relaying based on the DC offset elimination filter to minimize the effects of DC offset on a long transmission line. The proposed DC offset elimination filter has not need any prior information. The phase angle delay of the proposed DC offset filter did not occurred and the gain error was not found. The enhanced distance relay uses fault current as well as residual current. The behavior of the proposed distance relaying using off-line simulation has been verified using data about several fault conditions generated by the ATP simulation software.

• 대한소아치과학회지
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• 제29권2호
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• pp.262-269
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• 2002

본 연구는 할로겐광과 비교하여, 고강도의 단축된 중합 시간을 장점으로 하는 플라즈마광의 효율성을 평가할 목적으로, 첫째, 중합 시간과 중합 거리에 따른 중합도의 변화를 검토, 광조사 시간을 증가시킬 경우 특정거리 이상에서도 수복물 하층까지 충분한 중합이 이루어지는지 알아보고, 둘째, 중합 반경에 따라 균일한 중합이 이루어지는지 보기 위해 광조사 부위의 중심부와 외측 변연부의 중합도 차이를 비교하였다. 2mm 두께의 복합레진 시편의 상 하면 미세경도 측정을 통해 중합도를 비교해 본 결과, 다음과 같은 결론을 얻었다. 1. 거리증가에 따른 상대광도의 감소는 할로겐광에 비해 플라즈마광에서 그 차이가 적었다(p<0.05). 2. 플라즈마광, 할로겐광 모두 상면의 미세경도는 중합거리 2mm 이상부터 유의하게 감소되었으며, 중합시간의 증가에 따라 증가되었다(p<0.05). 3. 플라즈마광 3초를 제외하고, 하면의 미세경도 변화는 4mm 이상에서 급격히 감소하였으며, 상면에 비해 중합시간과 거리의 영향을 많이 받았다(p<0.05). 4. 플라즈마광, 할로겐광 모두 조사시간의 증가에도 불구하고 4mm와 6mm 사이에서 하면의 미세 경도차는 비교적 크게 나타났다(p<0.05). 5. 플라즈마광을 $6{\sim}9$초 적용한 때와 할로겐광을 $40{\sim}80$초 적용한 때의 미세경도치 및 거리에 따른 경도 변화는 유사하였다(p>0.05). 6. 플라즈마광, 할로겐광 모두 레진 시편의 중앙에서 외측으로 갈수록 미세경도는 유의하게 감소하였다(p<0.05).

• 한국운동역학회지
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• 제25권2호
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• pp.149-155
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• 2015

Purpose : Recently, many researchers and golf coachers demonstrated that X-factor and X-factor stretch had a co-relationship with driving distance. However, its relationship is still controversial and ambiguous. Thus, the aim of this study was to examine the relationship among X-factor, X-factor stretch and swing-related factors, including driving distance in elite golfers. Method : Seventeen male elite golfers (handicap: ${\leq}4$) with no history of musculo-skeletal injuries participated in the study. Thirty spherical retro-reflective markers were placed on including the middle point of PSIS, the right/left ASIS, the right/left lateral acromion of the scapula, driver head and shaft grip. All motion capture data was collected at 100Hz using 6 infrared cameras. Carry distance, club speed, ball speed, smash factor, launch angle, and spin rate were collected from radar-based device, TrackMan. Results : Pearson's correlation coefficient method was used to find the correlations among X-factor, X-factor stretch and swing-related factors. Positive correlations between driving distance and other swing-related factors which include club speed(r=.798, p<.001), and ball speed(r=.948, p<.001) were observed. In contrast to the swing-related factors, X-factor and X-factor stretch had no relationship to driving distance. Conclusion : These results indicate that X-factor and X-factor stretch are not key regulators in driving distance.

• 한국운동역학회지
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• 제22권4호
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• pp.421-428
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• 2012

The purpose of this study was to verify the effects of developed assisting wear which maximize trunk(back) muscle's stretch-shortening effect during backswing and downswing for increasing golf ball carrying distance. Design and fabrication of assistive wear were performed based on the results of analyzed data of trunk EMG activity from the golf drive swings of elite professional male golfers during back swing and downswing phases. After the prototype of wear was produced, surface EMG and Flight scope tests were conducted to verify the effectiveness of the wear for increasing distance to the professional golfers. Results indicated that wearing trial showed significant longer carry distance than the non-wearing trial(p<.001). The carry distance of wearing trial showed an average 229 m compared to the non-wearing trial, the average 225 m. The swing with wearing also produced significantly faster ball speed than the trial without wearing(p<.05). Average 245 Km/h and 244 Km/h were produced for the swing with and without wearing trails, respectively. EMG results also indicated that the muscle activity of left psoas was significantly increased for wearing trial during downswing and near the impact. Thus, this may affect positively to increase club head speed. The activity of the left latissimus dorsi was dramatically increased during the final stage of swing. This generates elongation effect for longer follow-through and increased impulse between club and ball so eventually valid assistance to increase carry distance. Therefore, the developed assisting wear was proved to be effective tool for increasing golf ball carry distance with maximizing trunk(back) muscle's stretch-shortening effect during backswing and downswing.

• 한국전문물리치료학회지
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• 제30권2호
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• pp.152-159
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• 2023

Background: The gluteus medius (Gmed) plays a critical role in maintaining frontal plane stability of the pelvis during functional activities, such as one-leg lifting. Side-lying hip abduction (SHA) has been used as a dynamic test to evaluate Gmed function. However, the abduction force of the lower leg against the floor is not controlled during SHA. Therefore, hip abduction performance with contralateral adduction in the side-lying position (HAPCA) can be proposed as an alternative method to assess performance of hip abduction. If the number of HAPCA is related to the lateral pelvic shift distance, a new quantitative measurement for hip abductor function may be presented. Objects: This study aimed to investigate the relationship between the number of successful HAPCA and the lateral pelvic shift distance during one-leg lifting. Methods: Thirty healthy participants were recruited, and lateral pelvic shift distance was measured during one-leg lifting test using two-dimensional analysis. The number of successful HAPCA was counted when participants touched both target bars at the beat of a metronome. Results: There was a negative correlation between the number of HAPCA and lateral pelvic shift distance during one-leg lifting (r = -0.630, p < 0.05). The number of HAPCA accounted for 39.7% of the variance in the lateral pelvic shift distance during one-leg lifting (F = 18.454, p < 0.001). Conclusion: The number of successful HAPCA is significantly correlated with lateral pelvic shift distance during one-leg lifting. This finding suggests that HAPCA can be proposed as a new measurement for hip abductor performance and more research is needed on its relationship with hip abductor strength.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권4호
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• pp.350-359
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• 2005

Sagittal split ramus osteotomy(SSRO) has been commonly performed in the mandibular prognathism. The previous studies of the mandibular anatomy for SSRO have mostly been used in dry skull without consideration of age, sex or jaw relationship of patients. This study was performed to evaluate the location of mandibular canal and the anatomy of ramus, such as the location of mandibular lingula and the ramal bone marrow, which were associated with SSRO procedures, in the patients with mandibular prognathism and normal young adults by using computerized tomographs(CT) and 3D images. The young adults at their twenties, who were considered to complete their skeletal growth, and seen in the Department of Orthodontics and Oral and Maxillofacial Surgery in Chonnam National University Hospital between March 2000 and May 2003, were selected. This study was performed in 30 patients (15men, 15women) who were diagnosed as skeletal class I normal relationship, and another 30 patients (15men, 15women) who were diagnosed as skeletal class III relationship upon clinical examination and lateral cephalometric radiographs. The patients were divided into 2 groups : Class I group, the patients who had skeletal class Ⅰ normal relationship(n=30, 15men, 15women), and Class III group, the patients who had skeletal class III relationship(n=30, 15men, 15women). Facial CT was taken in all patients, and pure 3D mandibular model was constructed by V-works version 4.0. The occlusal plane was designed by three points, such as the mesiobuccal cusp of both mandibular 1st molar and the incisal edge of the right mandibular central incisor, and used as a reference plane. Distances between the tip of mandibular lingula and the occlusal plane, the sigmoid notch, the anterior and the posterior borders of ramus were measured. The height of ramal bone marrow from the occlusal plane and the distance between mid-point of mandibular canal and the buccal or lingual cortex of the mandible in the 1st and 2nd molars were measured by V-works version 4.0. Distance(Li-OP) between the occlusal plane and the tip of mandibular lingula of Class III Group was longer than that of Class I Group in men(p<0.01), but there was no significant difference in women between both groups. Distance(Li-SN) between the sigmoid notch and the tip of mandibular ligula of Class III group was longer than that of Class I Group in men(p<0.05), but there was no significant difference in women between both groups. Distance(Li-RA) between the anterior border of ramus and the tip of mandibular lingula of Class III Group was shorter than that of Class I Group in men and women(p<0.01). Distance(Li-RP) between the posterior border of ramus and the tip of mandibular lingula of Class III Group was slightly shorter than that of Class I Group in men(p<0.05), but there was no significant difference in women between both groups. Distance(RA-RP) between the anterior and the posterior borders of ramus of Class III Group was shorter than that of Class I Group in men and women(p<0.01). Longer the distance(SN-AN) between the sigmoid notch and the antegonial notch was, longer the vertical ramal length above occlusal plane, higher the location of mandibular lingula, and shorter the antero-posterior ramal length were observed(p<0.01). Height of ramal bone marrow of Class III Group was higher than that of Class I Group in men and women(p<0.01). Distance between mandibular canal and buccal cortex of Class III Group in 1st and 2nd lower molars was shorter than that of Class I Group in men and women (p<0.05 in 1st lower molar in men, p<0.01 in others). These results indicate that there are some anatomical differences between the normal occlusal patients and the mandibular prognathic patients, such as the anterior-posterior length of ramus, the height of ramal bone marrow, and the location of mandibular canal.

• 한국임상보건과학회지
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• 제5권1호
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• pp.816-824
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• 2017

Purpose. This study was classified into normal and demented elderly through K-MMSE. The purpose of this study was to analyze gait characteristics of normal elderly and demented peoples using GAITRite walking system. Methods. The subjects of this study were selected as elderly people receiving home visit physical therapy. An independent t-test was conducted to verify the statistical significance of the time-space variables of the elderly with dementia. Results. Step time(p=0.041), cycle time(p=0.037), distance(p=0.024), and cadence(p=0.048) were significantly shorter in the normal elderly than in the demented elderly on flat place. The mean age was significantly longer in normal elderly than in elderly persons with dementia. Step time(p=0.022), cycle time(p=0.023), distance(p=0.019), and cadence(p=0.015) were significantly shorter in the mat walking. The mean age was significantly longer in normal elderly than in elderly patients with dementia. Stretch time, cycle time, distance, and hair support time were significantly shorter in the mat walking. The mean age of the elderly was significantly longer than that of the elderly with dementia. The spinal support time, which is a spatial variable, was significantly shorter in the normal elderly than in the demented elderly. Conclusions. It compares the various gait characteristics of the normal and demented elderly people, thereby increasing the walking ability of the elderly person more effectively. This study should be utilized as basic data for preventing fall-down.

• 환경생물
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• 제18권2호
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• pp.237-246
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• 2000

섬 생물지리학에서 평형설(equilibrium theory)은 섬의 면적과 본토에서 떨어진 거리에 따른 이입율과 절멸율의 작용에 의해 섬에 분포하고 있는 종 수가 결정된다는 이론이다. 본 연구는 한반도 부속도서에서 여러 생태학적인 요인들인 섬의 면적, 격리정도, 위도 및 섬의 최고 고도로 표시한 서식지 다양성과 나비의 종 수에 관한 상관관계를 파악하기 위하여 71개의 섬에서 기록된 나비의 종 수와 이들 요인들 사이의 상관분석 및 회귀분석을 실시하였다. 그 결과 나비 종 수는 섬 면적($r^2$=0.405, P<0.005) 및 고도로 표시한 서식지 다양성($r^2$=0.341, P<0.005)과는 유의한 상관관계를 보였으나 본토와의 거리 ($r^2$=0.018, P>0.05)및 섬 위도($r^2$=0.040, P>0.05)와는 유의한 상관관계를 나타내지 않았다. 본 연구와 이전의 연구결과를 종합해보면 한반도 부속도서의 나비 종 수는 섬의 면적, 식생 그리고 최고 고도와 같은 생태적 변수에 영향을 받는 것으로 요약된다.

• The Korean Journal of Pain
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• 제33권3호
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• pp.226-233
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• 2020

Background: We aimed to compare interlaminar epidural steroid injections (ILESI) and bilateral transforaminal epidural steroid injections (TFESI) on pain intensity, functional status, depression, walking distance, and the neuropathic component in patients with lumbar central spinal stenosis (LCSS). Methods: The patients were divided into either the ILESI or the bilateral TFESI groups. Prime outcome measures include the numerical rating scale (NRS), Oswestry disability index (ODI), Beck depression inventory (BDI), and pain-free walking distance. The douleur neuropathique en 4 questions score was used as a secondary outcome measure. Results: A total of 72 patients were finally included. NRS, ODI, and BDI scores showed a significant decline in both groups in all follow-ups. Third-month NRS scores were significantly lower in the ILESI group (P = 0.047). The percentages of decrease in the ODI and BDI scores between the baseline and the third week and third month were significantly higher in the ILESI group (P = 0.017, P = 0.001 and P = 0.048, P = 0.030, respectively). Pain-free walking distance percentages from the baseline to the third week and third month were significantly higher in the ILESI group (P = 0.036, P < 0.001). The proportion of patients with neuropathic pain in the bilateral TFESI group significantly decreased in the third week compared to the baseline (P = 0.020). Conclusions: Both ILESI and TFESI are reliable treatment options for LCSS. ILESI might be preferred because of easier application and more effectiveness. However, TFESI might be a better option in patients with more prominent neuropathic pain.

• 대한의용생체공학회:의공학회지
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• 제31권1호
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• pp.50-55
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• 2010

Gait initiation is a transitional process from the balanced upright standing to the beginning of steady-state walking. Dysbalanced gait initiation often causes stroke patients to fall. The net center of pressure, measured by two triaxial force plates from twenty healthy subjects and two stroke patients, was investigated to assess asymmetry of gait initiation in hemiparetic subjects. The time interval and distance of the net center of pressure(CoP) moved from the initiation point to the toe off(S1) and from the toe off to the initial contact(S2) were calculated during gait initiation of normal and stroke patients. When the patient with right hemiplegia(A) initiated his gait with right foot, the time interval and the distance of the net CoP in S1 and S2 were smaller than that of normal subjects' values. However, he initiated the gait with left foot(unaffected side) the time interval and the distance of net CoP in S1 were larger than normative values. Differently, the patient with left hemiplegia(B) has shown that larger time interval and distance in S1 and smaller time interval and distance in S2 in both sides. His asymmetry(with which side the gait initiated) was not significant. It is too early to conclude that these results could be general characteristics of the stroke patients because the variations were large and moreover, the level of motor recovery of the patients was different. However, it is expected that these trials could help to set up the strategy of the therapy for the rehabilitation or prevention of fall in stroke patients.