• 한국전자파학회논문지
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• 제24권3호
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• pp.292-298
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• 2013

본 논문에서는 미사일의 길이를 추정하는 신호 처리 기법의 개발에 관하여 소개한다. 표적의 길이를 추정하기 위해서는 미사일의 위치 및 표적과 레이더와의 각도 정보가 필요하다. 미사일의 위치 및 각도를 알아내기 위해서 chirp 파형을 사용했고, 레이더 영상 신호인 HRRP(High Resolution Range Profile)를 발생시키기 위해 stretch processing을 이용하였다. HRRP로부터 표적의 산란점(scattering center)을 찾기 위해 스펙트럼 추정 방법(spectral estimation technique)인 Relaxation(RELAX) 알고리즘을 이용하였다. 이 알고리즘으로부터 얻은 1차원 산란점의 정보를 이용하여 미사일의 길이를 추정하였다.

• PNF and Movement
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• 제16권2호
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• pp.229-238
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• 2018

Purpose: This study aimed to compare the immediate effects of various contract-relax (CR) techniques on the peck force and passive range of motion (ROM) of knee extension. Methods: This study recruited 17 adult males and females who obtained below $90^{\circ}$ in straight leg raising. The subjects randomly performed one of three different CR techniques (direct CR, indirect CR, and modified CR) on the right knee extension four times per day for three days. The subjects' peck force during each CR and their passive knee extension on the hip at a $90^{\circ}$ flexed position before and after each CR were measured. Results: The peck force was significantly higher in the direct and modified CR than in the indirect CR. The ROM in the passive knee extension significantly increased after direct and indirect CR. Comparing between each CR, the passive knee extension range was significantly more improved in the direct and indirect CR than in the modified CR. Conclusion: Direct and indirect CR are more effective than modified CR in the ROM of passive knee extension. The study results suggest that the modified CR did not have the same effect on the ROM of the knee extension as the direct and indirect CR and that further research is needed to recruit more subjects and to determine the effects on different muscles after modified CR.

• 대한물리의학회지
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• 제2권1호
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• pp.1-10
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• 2007

Purpose : To identify the effects of Hold-Relax of proprioceptive neuromuscular facilitation (PNF) on the functional improvement of patients with neck myofascial pain syndrome. Methode : The present research investigated 60 patients with neck myofascial syndrome, dividing them into a group doing Hold-Relax of proprioceptive neuromuscular facilitation and a group doing Stretching, This study examined degree of recovery from neck pain by comparing their neck myofascial pain syndrome before and after the treatment, and compared two groups to find difference in the degree of recovery from myofascial pain syndrome. Results : 1. For Hold-Relax of proprioceptive neuromuscular facilitation group, the pain rating score (PRS) were significantly decreased for six weeks treatment. 2. For Stretching group, the pain rating score (PRS) did not indicate significant decrease for six weeks treatment. 3. For Hold-Relax of proprioceptive neuromuscular facilitation group, range of motion of flexion, left rotation, right rotation indicated significant difference after pre test and after two week but no significant difference after four week. 4. For Stretching group, range of motion of flexion, left rotation, and right rotation except extension indicated significant difference after pre test and after two week but no significant difference after four week. Conclusion : The Hold-Relax of proprioceptive neuromuscular facilitation is considered to be effective in increasing joint range of motion of patient and decreasing pain. Accordingly physical therapists has to learn a wide range of patterns and to develop various treatment techniques.

• 한국전문물리치료학회지
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• 제2권2호
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• pp.56-65
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• 1995

The purpose of this study was to compare the effects of one proprioceptive neuromuscular facilitation technique and static stretching on calf muscle tightness. The subjects consist of 9 hemiplegics, and 9 quadriplegics. The eighteen subjects were randomly divided into 3 groups: prorioceptive neuromuscular facilitation(6 persons), static stretching(6 persons) and control(6 persons). Contract relax antagonist contract and static stretching techniques were applied continuously for twenty minutes each. Of the many proprioceptive neuromuscular facilitation techniques, only the contract relax antagonist contract technique was applied. The static stretching technique was applied with the subject placed in standing on a seventy degree inclined tilt table for twenty minutes. A wedge was placed under the feet to obtain maximum dorsiflexion. Wedge thickness varied with each subject. Results revealed: (1) a significant difference between the experimental and the control groups(p<0.05). (2) a significant difference between contract relax antagonist contract and static stretching groups(p<0.05). (3) At day five, the final increments were: contract relax antagonist contract $11.9{\pm}1.90^{\circ}$, static stretching $7.7{\pm}2.3^{\circ}$(mean${\pm}$standard deviation).

• 대한물리치료과학회지
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• 제19권3호
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• pp.39-47
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• 2012

Background : Patients with frozen shoulder have pain and limited range of motion (ROM) at the affected shoulder. Shoulder pain of these patients usually decreases with recovery of range of motion. The aim of this study is to identify effects of static stretching and hold-relax on recovering ROM and reducing pain of patients with frozen shoulder. Methods : In this study, 15 patients with frozen shoulder who were only treated with physical therapy were recruited. Patients who received any surgical procedure or hydrotherapy were excluded. The subjects were divided randomly into 3 groups; control(n=5), static stretching(n=5) and hold-relax(n=5) groups. Patients were treated with stretching and the total number of treatments was 12 times. The ROM was measured at baseline, after fourth, eighth and final treatments. Shoulder pain and disability index(SPADI) scores were assessed before and after doing all treatments. Repeated measures ANOVA was used to analyze ROM change within each group. Changes of ROM between groups was analyzed by one way ANOVA followed by post hot analysis(Tukey's HSD). SPADI score within each group analyzed using Wilcoxon signed ranks test. A p-value<0.05 was considered statistically significant. Study Design : Repeated measures design. Result : There were significant differences of ROM in both treatment groups except internal rotation of static stretching group. ROM was significantly increased in treatment groups compared with control group, but the difference of ROM change between two treatment groups did not differ significantly. SPADI scores for treatment groups significantly decreased compared with pre-SPADI score. Conclusion : The result suggests that hold-relax can be more effective than static stretching to recover range of motion and alleviate shoulder pain on patients with frozen shoulder.

• PNF and Movement
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• 제7권4호
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• pp.1-7
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• 2009

Purpose : This paper reviews on the method of PNF stretching. Methods : This is literature study with Pubmed, medline, SPORT Discus, EBSCO, ProQuest and books. Results : PNF stretching is effective for increasing range of motion than static and ballistic stretching. CR(contract-relax) technique is effective and CRAC(contract-relax with agonist contraction) technique including agonist contraction is more effective. A minimum of one repetition, twice or three times per week is required for range of motion gains, needs to be conducted continueously. A minimum of 20% contraction intensity and more than 3 seconds contraction duration are needed to increase range of motion. Inclusion of static stretching of antagonist and agonist contraction is more effective. Conclusions : PNF stretching is more effective for increasing range of motion than other stretching methods, but, clinicians need to select proper techniques according to subjects and muscles, and conduct carefully when applying technique.

• 자동차안전학회지
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• 제15권4호
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• pp.48-57
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• 2023

With the advance of autonomous vehicle technology various sitting posture is possible like relax position (inclined seating posture). Parametric study was done with MADYMO, a mutibody dynamics solver, to investigate the effect of sitting posture in different frontal crash modes, full frontal, 40% offset, and angled rigid barrier crash as well as various impact speeds. Hybrid III 50th male and 5th female dummies were used to figure out the difference induced by occupant weight and dimension. Restraint system parameters complying to current safety protocols like NCAP are studied if they still work effectively in relax position which is feasible with autonomous vehicles.

• Physical Therapy Rehabilitation Science
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• 제8권4호
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• pp.210-217
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• 2019

Objective: This study was conducted to compare the immediate effect of hamstring stretching techniques of static stretching, proprioceptive neuromuscular facilitation (PNF) hold-relax and PNF irradiation on the hamstring muscle. Design: Three-group pretest-posttest design. Methods: Fifty-one subjects with shortened hamstrings were randomly assigned to the static stretching group (n=17), PNF hold-relax group (n=17), and the PNF irradiation group (n=17). All subjects performed an active knee extension (AKE) test to assess for the lower extremity with a shortened hamstring. The static stretching group performed stretches by lifting their leg to the maximum extent (3 times, 30 seconds). The PNF hold-relax group performed maximal isometric contraction against the experimenter's resistance (3 times, 10 seconds). The PNF irradiation group performed maximum isometric contraction against the experimenter's resistance toward the direction of the body (5 times, 5 seconds). The pre and post-tests measured range of motion (ROM), pressure pain thresholds (PPT) and muscle tone. Results: There were significant differences in ROM and PPT between pre and post intervention in each group (p<0.05). There was a significant difference only in the ROM among groups (p<0.05). Post-hoc analysis showed that the changes in ROM occurred in the order of the PNF hold-relax group, static stretching group and PNF irradiation group (p<0.05). Conclusions: The findings of this study suggest that the PNF irradiation technique may improve ROM and may be used to improve ROM similar to other stretching techniques. Therefore, the PNF irradiation technique could be included in stretching programs and can be used as a suitable stretching method depending on the situation.

• 폴리머
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• 제36권4호
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• pp.507-512
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• 2012

순수 PMMA와 methacryl-polyhedral oligomeric silsesquioxane(Ma-POSS)를 5 wt% 첨가한 PMMA를 박막(~650 nm)과 초박막(~50 nm)으로 제조하였으며, 유리전이온도($T_g$)와 등온 물리적 시효에 미치는 박막의 두께에 미치는 POSS의 첨가 효과를 시차주사열량계(DSC)를 이용하여 조사하였다. 초박막화와 Ma-POSS의 첨가로 인해 $T_g$ 감소가 관찰되었다. 또한 등온 물리적 시효에 의한 엔탈피 완화값(${\Delta}H_{Relax}$)도 초박막화 Ma-POSS를 첨가하였을 때 감소하였다. 시효시간에 따른 ${\Delta}H_{Relax}$ 데이터에 KWW(Kohlrausch-Williams-Watts)식을 적용하여 최대 엔탈피(${\Delta}H_{\infty}$), 이완시간(${\tau}$) 그리고 이완시간의 분포상수(${\beta}$)를 결정하였으며 이를 비교 분석하였다.

• PNF and Movement
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• 제13권3호
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• pp.135-143
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• 2015

Purpose: The purpose of this study was to assess the effect of the proprioceptive neuromuscular facilitation (PNF) relaxation technique (hold relax; HR, contract relax; CR) and static stretch (SS) on hamstring flexibility and vertical jump performance in healthy adults over a four-week period. Methods: Twenty-four healthy adults volunteered to participate in PNF and static stretch sessions. The subjects were divided into three groups as follows: 8 subjects in the SS group, 8 subjects in the HR group, and 8 subjects in the CR group. In the HR and CR groups, contractions lasted 15 seconds per trial and consisted of 5 sets of 15 seconds of hamstring contraction immediately followed by 15 seconds of passive static hamstring stretching. For the static group, the participants were asked to stretch by hanging a leg over a table for 30 seconds. Subjects in all groups performed the exercises three days per week for 4 weeks. The active straight leg raising (ASLR) test, active knee extension (AKE) test, and vertical jump test were performed before the intervention and after 1, 2, and 4 weeks. Results: The SS, HR, and CR techniques effected positive improvement in hamstring flexibility and vertical jump performances but neither of the stretching methods had any statistically significant different effects according to group, although there were interactions (between group and time) in the ALSR group from 1 week to 2 week and in the AKE test from pretest to 1 week. Conclusion: Based on the results of the current study, SS, HR, and CR were shown to affect hamstring flexibility and vertical jump performance in healthy adults. In particular, it was determined that within a short period, hamstring flexibility could be attributed more to CR than to SS.