• 한국환경농학회지
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• 제37권3호
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• pp.179-188
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• 2018

BACKGROUND: Reclamation of heavy metal-contaminated agricultural fields has intensively been done to ensure the soil quality and food security. This study evaluated the efficiency and longevity of current physical and chemical approaches for heavy metal-contaminated soils. METHODS AND RESULTS: Concentrations of 0.1 N HCl-leachable trace metals of Cd, Pb, and As from the stabilizing agents-treated soils decreased by 50%, 70%, and 40%, respectively, compared to the control. Among the stabilizing agents, the $CaCO_3$ was the best for stabilization. For physical stabilization, the soil dressing reduced the concentrations of Cd, Pb, and As by 88%, 94%,and 88%, respectively, compared to the control. Moreover, the dilution of the contaminated soils decreased the metals by an average of 25.3% when compared with the control. The longevity of each stabilization method was determined by using the availability assessment of heavy metals in the soils. Results showed that the leaching methods using HCl and $NH_4NO_3$ had 120 and 32 weeks longevity, respectively. Interestingly, any stabilization efficacy was not found over the time for Cd and Pb (i.e., cation metals), whereas the stabilization efficacy of As was sharply decreased under 50% after 32 weeks. However, the change of metal concentration was not significant with the physical stabilization compared to the chemical stabilization. CONCLUSION: The stabilization methods should carefully be selected based on long-term monitoring under climate conditions.

• 대한임상전기생리학회지
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• 제7권1호
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• pp.43-48
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• 2009

Purpose : The purpose of this study was to study the effect of rectus abdominal muscle contraction by proprioceptive neuromuscular facilitation trunk stabilization training using extremity simultaneous pattern (PNF trunk stabilization training) and traditional trunk stabilization training methods. Methods : A group of 24 adults male and female, healthy, with no previous medical history nor disability in neuromuscular system and musculoskeletal system was chosen as subjects, and was divided into a control group, a PNF trunk stabilization training group and a traditional trunk stabilization training group. Experiments were performed on the last two groups, 3 times a week for 6 weeks, totaling 18 times. Using a dynamometer, muscle strength and endurance time on trunk flexion were measured before and after each experiment, and surface electromyography in left and right rectus abdominis were measured. Results : following results were obtained; 1. As for the change in the maximal voluntary isometric contraction (MVIC), all subjects in the trunk stabilization training group showed significant difference from those in the control group. 2. As for surface electromyography measurement and the changes in root mean square at the time of trunk flexion, in the left rectus abdominis, PNF trunk stabilization training group showed significant difference from the control group, while in the right rectus abdominis, traditional trunk stabilization training group showed significant difference. Conclusion : To sum up the results, both trunk stabilization training groups showed improvement in the MVIC of abdominal muscle, motor unit action potential activity, but the difference between two trunk stabilization training groups was not significant. Therefore, while trunk stabilization training significantly improved abdominal muscle contraction, but the difference attributable to training methods was found to be insignificant.

• 전기의세계
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• 제31권1호
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• pp.59-67
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• 1982

This paper suggests easy stabilization methods for linear time-varying systems with delay in the state. While existing methods employ the function space concept, the methods introduced in this paper transform the delay systems into the non-delay systems so that the well known methods for finite dimensional systems can be utilized. Particularly the intervalwise predictor is introduced and shown to satisfy an ordinary system. Control laws stabilizing the non-delay systems satisfied by this predictor will be shown to at least pointwise stabilize the delay systems with the additional strong possibility of true stabilization. In order to combine two steps of the predictor method, first transformation and then stabilization, an intervalwise regulator problem is suggested whose optimal control laws incorporate the intervalwise predictor as an integral part and also at least pointwise stabilize the delay systems. Since the above mentioned methods render the periodic feedback gains for time invariant systems the pointwise predictor and regulator are introduced in order to obtain the constant feedback gains, with additional stability properties. The control laws given in this paper are perhaps simplest and easiest to implement.

• 한국산림과학회지
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• 제108권4호
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• pp.582-591
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• 2019

본 연구는 산림작업로의 사용이후에 존치시켜 지속적으로 활용하기 위하여 필요한 저비용 구조의 간이 사면안정구 조물을 개발하고, 그 시공효과를 살펴보고자 실시하였다. 국립산림과학원 산림기술경영연구소 관내에 시설된 산림작업로의 성토사면에 안정구조물을 시공하였다. 성토사면 간이 안정구조물에 대하여 차량의 통행으로 인한 노면 침하량 및 지지력 분석을 실시하였고, 모든 사면안정구조물에 대해서는 차량통행으로 인한 안정구조물의 변위량을 측정하여 안정성을 판정하였다. 성토사면 간이 사면안정구조물을 대상으로 한 소운재 차량(총 중량 17톤)을 최대 100회(목재운송량 780 ㎥)까지 통행 후 운송횟수별 노면의 지지력과 침하량을 분석한 결과, 안정처리공법별로 노면의 침하량은 최대 150 mm 이하로 양호한 것으로 나타났으나, 노면지지력의 효과는 크게 없는 것으로 나타났다. 또한, 안정구조물의 안정성을 평가한 결과, 뿌리쌓기 공법에서 안정성이 다소 낮았으나, 대체로 모든 구조물의 평균 변위량이 약 20 mm이하로 구조적 안정성에는 큰 문제가 없는 것으로 나타났다. 이와 같이 목재생산 이후에 존치되는 산림작업로를 대상으로 간이한 사면안정구조물을 적용한다면 효율적 목재생산이 가능할 뿐만 아니라, 부족한 임도를 보완할 수 있는 영구적인 생산기반시설로 활용이 가능할 것으로 사료된다.

• 전자공학회논문지S
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• 제34S권10호
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• pp.52-58
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• 1997

In this paper, we consider methods of robust stabilization of the interval plant with a PID controller. Suppose that we know apriori a sign of the coefficients of the numerator of the PID controller. Under this condition, it sufficies to make eight polynomials stable for robust stabilization of the interval plant with a minimum phase PID controller. In addition, with a nonminimum phase PID controller, it suffices to make different eight polynomials stable. Especially, with the nonminimum phase PID controller it is shown that stabilization of eight plants is necessary and sufficient for robust stabilization of the interval plants.

• 전기학회논문지
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• 제67권11호
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• pp.1555-1561
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• 2018

Tracking and detecting targets by the millimeter wave seeker is affected by movement of platform. Stabilization equipments use an inertial sensor to compensate for disturbance of stabilizing gimbal or platform. In the direct line of sight stabilization system, an inertial sensor is mounted on inner gimbal to compensate the disturbance directly, so the performance is excellent and the implementation method is simple. However gimbal design requires somewhat larger volume. Since an inertial sensor is mounted on gimbal base in the indirect line of sight stabilization system, additional space of gimbal is not required for the gimbal design. However, this method does not directly compensate for the disturbance of the line of sight stabilization axis, which can degrade performance. In order to perform the tracking performance, two methods are analyzed for line of sight stabilization performance based on direct and indirect of a 2-axis gimbaled servo system for millimeter wave seeker in this study. The simulation and experimental results validate the performance comparison of two methods.

• 대한물리치료과학회지
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• 제29권4호
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• pp.96-111
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• 2022

Background: This study aims to evaluate the effect of core stabilization exercise on the dynamic balance and horizontal rotation of the trunk in young adult men. Through this study, it is expected that various core stabilization exercises will prevent and treat musculoskeletal disease. Design: Randomized Controlled Trial. Methods: The study subjects were recruited from young adult men in their 20s and 30s living in Seoul, and after the randomized controlled trial, it was divided into an experimental group training core stabilization exercise(n=15) and a control group(n=15). The evaluation methods of this study were modified Star Excursion Balance Test(mSEBT), Functional Reach Test(FRT), and Trunk Rotation Test(TRT). The experimental group performed three sets of crunches and deadbug exercises twice a week for eight weeks, and the control group did not perform any exercises similar to core stabilization exercise during the experimental period. Results: The result of the experiment, the experimental group showed significant improvement in mSEBT(p<.05), FRT(p<.05) and TRT(p<.05). Conclusion: In conclusion, core stabilization exercises improved dynamic balance and horizontal rotation of the trunk. As a result of this study, core stabilization exercise can prevent and treat musculoskeletal diseases even in healthy people.

• 한국정밀공학회지
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• 제9권3호
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• pp.102-109
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• 1992

The heavy vibrations of vehicles on the severe off-road environment degenerate the stabilization proformance of the gunner primary sight. To improve the stabilization performance, the dynamic equations of the gunner primary sight were derived, and the stabilization systems were designed using VSC methods. The performances were compared with the Lead/Lag scheme. In the nonlinear simulation including real disturb ances and couloumb friction, it is shown that the VSC methods exhibit more effective stabilization.

• 한국지반공학회논문집
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• 제16권2호
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• pp.79-89
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• 2000

The application of stabilization method has increased because of short construction periods, no environmental problems with dumped and replaced soil, assurance of required strength and economical effect with mid to small size construction. The unconfined and triaxial(UU-condition) compression tests were executed with each mixing sample for the study of the improvement effects and the effect of design-parameters by the stabilization methods. Three typical stabilizers, which are representative in Korea, were applied in this study, and three common soils(very soft clay, general weathered soil, common clay), which are common in Korea, were used in this study. In this study, the effect of engineering factors(soils, stabilizers and water contents, etc.) which are important parameters for the improvement effects of mixed ground by stabilizers, was analyzed. As results, the tendencies of design-parameters(unconfined compression strength, deformation modulus and strength parameter) are presented and the criteria of the application of stabilization methods are suggested.

• Physical Therapy Rehabilitation Science
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• 제10권1호
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• pp.69-75
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• 2021

Objective: This study was aimed at investigating the effects of lumbar stabilization exercise according to correct verbal instructions in pain and muscle strengthening of the low back pain patients. Design: A randomized controlled trial. Methods: Twenty subjects with low back pain were selected. They were randomly assigned to one of two groups (10 in each group): namely the lumbar stabilization exercise and lumbar stabilization exercise according to the correct verbal instructions group. The lumbar stabilization exercise group performed lumbar stabilization exercises for 6 weeks (5 times a week). The lumbar stabilization exercise according to correct verbal instructions group performed lumbar stabilization exercise according to correct verbal instructions for 6 weeks (5 times a week). We measured pain, muscle power, proprioception, and body balance before and after exercise by using visual analog scale (VAS), digital handheld dynanometer, Joint repositioning error, time up and go test respectively. Results: We found statistically significant differences in pain, muscle power, proprioception, and body balance in lumbar stabilization exercise and lumbar stabilization exercise according to correct verbal instructions group, before and after (p<0.05). Conclusions: We confirmed the effect of lumbar stabilization exercise according to correct verbal instructions. Thus we thought these results could be used as basic data and reference for low back pain. But we need more study effect of correct verbal instructions on other exercises.