• 대한통합의학회지
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• 제8권4호
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• pp.155-161
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• 2020

Purpose : This study was conducted to investigate the effect of positive active pressure technique and active breathing technique on lung function in healthy adults. Methods : In this study, the passive lung expansion technique and active respiration enhancement technique using an air mask bag unit were conducted in 30 normal adults to observe changes in pulmonary function with forced vital capacity (FVC), Forced expiratory volume at one second (FEV1). In order to observe the change in the level of respiratory function, we would like to investigate the peak expiratory flow (PEF) and the forced expiratory flow (FEF 25-75 %). Results : As a result of this study, there was no significant difference in comparison between the passive lung expansion technique and the active breathing enhancement technique (p>.05). The passive lung expansion technique effectively increased the effortful expiratory volume and the median expiratory flow rate of 1 second (p<.05). And the passive lung expansion technique effectively increased the effortless lung capacity and the maximum expiration flow rate (p<.05). Conclusion : The passive lung expansion technique effectively increases the range of motion of the lungs and chest cages, intrathoracic pressure, and elasticity of the lungs, and the active breathing technique increases the muscle functions such as the diaphragm and the biceps muscles. It is expected that it will be able to selectively improve the respiratory function of patients with respiratory diseases or functional limitations as it is found to be effective.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 추계학술대회 학술발표 논문집 제14권 제2호
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• pp.515-520
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• 2004

In this paper, a passive telemetry RF capacitive humidity sensor system using a RLSE(Recursive Least Square Estimation) technique is proposed. To overcome these trouble problems such as a power limitation and a estimation complexity that the general passive telemetry sensor system including It chip has, the principle of inductive coupling was applied to the modeling of a passive telemetry RF capacitive humidity sensor system and its capacitance was estimatedd by the RLSE algorithm. Specially, by introducing the optimal forgetting factor, we showed that the accuracy of its estimation was improved even in the time varying system and also the convergence time was reduced.

• 한국초전도ㆍ저온공학회논문지
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• 제20권2호
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• pp.29-33
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• 2018

Although high-temperature superconducting (HTS) magnets have the potential merit of producing ultra-high field (>25 T), they have been not easy to apply to Nuclear Magnetic Resonance (NMR) because of the difficulty of field homogeneity improvement. This paper presents a design technique of passive shimming for HTS magnets. Ferromagnetic shimming design code was developed though MALAB, which includes the optimization algorithm. The proper shim element size was determined by a simulation. This design technique was verified by a case study design of a 3-T HTS magnet. We succeed to improve field homogeneity of the magnet from 634 ppm to 6.39 ppm at 10-mm diameter sphere volume. Feasibility of passive shimming for all-HTS NMR magnet was confirmed by this result.

• 전기화학회지
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• 제3권4호
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• pp.211-218
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• 2000

마멸전극기법과 교류 임피던스법으로 스테인리스강의 합금원소, Cr, Mo, N가 합금의 재부동태 특성에 미치는 영향을 조사하였다. Fe-Cr, Fe-Cr-Mo, 304, 304LN, 316, 316LN등의 스테인리스강을 시편으로 사용하였으며 각 합금의 부동태 피막의 전기화학적 특성은 in-situ시험 기법인 d.c와 a.c전기화학적 기법을 각각 이용하였다 스테인리스강이 국부부식에 대하여 강한 저항성을 가지려면 부식 환경에서도 치밀한 부동태 피막을 유지해야 하고 피막의 파괴가 발생하더라도 재부동태 속도가 빨라야 하기 때문에 합금원소가 시간에 따른 재부동태 전류밀도와 재부동태 속도에 미치는 영향을 마멸 전극 시험법과 교류 임피던스 시험법으로 알아보았다. 부동태 피막의 안정성, 재부동태 속도 그리고 합금원소 사이의 관계를 규명하기 위하여 실험결과를 분석하였다.

• 대한물리의학회지
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• 제19권1호
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• pp.69-79
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• 2024

PURPOSE: This study compared the effect of the muscle energy technique (MET) and stretching technique on ankle dorsiflexion passive range of motion, balance, and gait ability of stroke patients with limited ankle dorsiflexion. METHODS: Forty-four post-stroke patients participated. The participants were randomized into the MET group (METG; n = 22) and the stretching group (STG; n = 22). The METG was subjected to the MET to relax the dorsiflexion, while the STG was subjected to the dorsiflexion stretching technique. Both groups completed standard neurological physical therapy for 30 min per session. The intervention was conducted five times a week over 3 weeks for a total of 15 times. All participants underwent ankle dorsiflexion passive range of motion measurement and Berg Balance Scale score determination and completed a 10-m walking test and the timed up and go test before and after the intervention. RESULTS: After the 3-week intervention, both groups showed significant improvement after the intervention (p < .05). METG participants showed greater improvements in ankle dorsiflexion passive range of motion and 10-m walking test results compared to STG participants (p < .05). CONCLUSION: Both interventions improved ankle dorsiflexion passive range of motion, balance, and gait ability in stroke patients with limited ankle dorsiflexion. Moreover, the MET was superior to ankle dorsiflexion passive range of motion on the 10-m walking test.

• 대한정형도수물리치료학회지
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• 제22권2호
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• pp.1-7
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• 2016

Background: The purpose of this study was to investigate the effects of between modified mulligan technique and modified mulligan technique with taping on the active range of motion & passive range of motion, scapula index into the stroke patients. Methods: The subjects with stroke were randomly divided into two groups. Group 1 (n=9) was conducted modified mulligan technique and Group 2 (n=9) was conducted modified mulligan technique with taping week three times for 4weeks. Active range of motion (AROM), passive range of motion (PROM) and scapula index (SI) were measured by goniometer and tape measure. Wilcoxon signed-rank tests were used to compare differences before and after intervention. Mann-Whitney U-test were conducted to compare before to after intervention in the two groups. Results: AROM was significantly different both groups (p<.05) and between groups were not significantly different into pre and post intervention (p>.05). PROM was significantly different both groups (p<.05) however, between groups were not significantly different into pre and post intervention (p>.05). SI was significantly different only group 2 and between groups were not significantly different (p>.05). Conclusions: This study demonstrated effective bo-th modified mulligan technique and modified mulligan technique with taping on the active range of motion and passive range of motion. Because only modified mulligan technique with taping are effective on the scapula index we recommend modified mulligan technique with taping than modified mulligan technique.

• Journal of Advanced Marine Engineering and Technology
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• 제28권4호
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• pp.569-576
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• 2004

In this paper, passive telemetry capacitive humidity sensor system using a RLSE(Recursive Least Square Estimation) technique is proposed. To overcome the problem like power limits and complications that general passive telemetry sensor system including IC chip has, the principle of inductive coupling is applied to model the sensor system. Specially. by applying the forgetting factor we show that the accuracy of its estimation can be improved even in the case of time varying parameter and also the convergence time can be reduced.

• Smart Structures and Systems
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• 제3권4호
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• pp.405-422
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• 2007

A new hybrid damping technique for vibration reduction in flexible structures, wherein a combination of layers of hard passive damping alloys and active (smart) magnetostrictive material is used to reduce vibrations, is proposed. While most conventional vibration control treatments are based exclusively on either passive or active based systems, this technique aims to combine the advantages of these systems and simultaneously, to overcome the inherent disadvantages in the individual systems. Two types of combined damping systems are idealized and studied here, viz., the Noninteractive system and the Interactive system. Frequency domain studies are carried out to investigate their performance. Finite element simulations using previously developed smart beam elements are carried out on typical metallic and laminated composite cantilever beams treated with hybrid damping. The influence of various parameters like excitation levels, frequency (mode) and control gain on the damping performance is investigated. It is shown that the proposed system could be used effectively to dampen the structural vibration over a wide frequency range. The interaction between the active and passive damping layers is brought out by a comparative study of the combined systems. Illustrative comparisons with 'only passive' and 'only active' damping schemes are also made. The influence and the mode dependence of control gain in a hybrid system is clearly illustrated. This study also demonstrates the significance and the exploitation of strain dependency of passive damping on the overall damping of the hybrid system. Further, the influence of the depthwise location of damping layers in laminated structures is also investigated.

• 대한기계학회논문집B
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• 제20권12호
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• pp.3980-3990
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• 1996

When a moist air is rapidly expanded in a supersonic nozzle, nonequilibrium condensation occurs at a supersaturation state. Condensation shock wave appears in the nozzle flow if the releasing latent heat due to condensation goes beyond a critical value. It has been known that self-excited oscillations of the condensation shock wave generate in an air or a steam nozzle flow with a large humidity. In the present study, the passive control technique using porous wall with a cavity underneath was applied to the condensation shock wave. The effects of the passive control on the steady and self-excited condensation shock waves were experimentally investigated by Schlieren visualization and static pressure measurements. The result shows that the present passive control is a useful technique to suppress the self-excited oscillations of condensation shock wave.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.991-996
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• 2014

Power frequency magnetic field is still a critical problem for new construction of overhead power transmission lines in Korea because most people have been concerned about possibly carcinogenic effects of it. Although reference level of power frequency(60Hz) magnetic field has been set to 200uT in ICNIRP guidelines published in 2010, Korean government has no intention of adjusting 83.3uT specified by law in 2006 to this new reference level in consideration of people's concerns for the time being. Regardless of the current regulated magnetic field value, electric utility company has been trying to reduce magnetic field in the residential area in the vicinity of overhead power transmission lines to take into account of public concerns on the long-term effect of magnetic fields. In an effort to reduce magnetic field, engineering side has made considerable efforts to develop passive loop based, cost-effective mitigation technique of power frequency magnetic field more than ten years. In order to verify developed power frequency magnetic field mitigation technique based on passive loop, a horizontal type of passive loop was designed and installed for commercially operating 154kV overhead power transmission line for the first time in Korea. The measurement results before and after the installation of passive loop showed that magnetic field could be reduced to about 20%. The electrical environmental effects such as AN, RI and TVI were assessed before and after the installation of passive loop and these values were complied with the requirements specified by electric utility. It has been confirmed from the field test results that passive loop could be commercially and cost-effectively utilized to mitigate power frequency magnetic field.