• 한국전문물리치료학회지
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• 제14권2호
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• pp.68-75
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• 2007

Reductions in strength and range of motion in older persons have been associated with decreased functional mobility and risk of falls. The purpose of this research was to investigate the effect of intensive dynamic balance exercise (DBE) during 8 weeks on onset time of medial gastrocnemius and tibialis anterior muscle contraction after perturbation in older women. Thirty subjects were randomly assigned into DBE group or control group. The DBE group participated in 50 minutes 3 days a week for 8 weeks. Surface electromyography (EMG) activity was recorded from the medial gastrocnemius and tibialis anterior muscles of left side. Outcome data were collected both groups at the pre-exercise and post-exercise. Independent t-test and paired t-test were used to determine the statistical difference. Results showed that the passive range of motion and functional reach test were significantly increased in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles and discrepancy of onset time significantly reduced in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles were significantly reduced in the post-exercise than the pre-exercise in the DBE group (p<.05). The discrepancy of onset time in the DBE group was significantly reduced in the post-exercise than the pre-exercise (p<.05). These findings suggest that intensive dynamic balance exercise for the eight weeks was effective in improving the postural control with older persons.

• 핵의학기술
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• 제24권1호
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• pp.27-32
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• 2020

사구체 여과율은 신 기능의 평가와 신 질환의 경과 관찰에 중요한 지표다. 현재 임상에서 사구체 여과율을 측정하는 방법은 크게 혈청 크레아티닌 수치와 ^99mTc-DTPA을 이용해서 계산하는 검사가 유용하게 이용되고 있다. Gates 공식이 발표된 이후, ^99mTc-DTPA Renal Dynamic Scan 검사시 이를 적용해 GFR을 감마카메라 장비를 이용하여 측정하고 있다. 본 논문의 목적은 Gates 공식을 적용해 사구체 여과율을 측정할 때 동위원소의 용량 변화, Matrix Size 변경에 따른 사구체 여과율을 분석해 보고자 한다. 본원에서 ^99mTc-DTPA Renal Dynamic Scan 검사를 받은 성인 환자 5명 (환자나이 = 62 ± 5, 남자 3명, 여자 2명)의 결과를 분석하였다. ^99mTc-DTPA 15 mCi를 환자의 정맥에 순간 주사 후 21분간 동적 영상을 획득하였다. Activity, Matrix Size 변화에 따라 사구체 여과율을 평가하기 위해 2-3분 구간의 양쪽 신장과 조직에 관심 영역을 설정 후 총 계수를 측정하였다. Detector와 Table 간의 거리는 30cm로 유지하였고, 동위원소의 용량 변화 평가를 위해 Pre Syringe(PR)의 용량을 15, 20, 25, 30 mCi로 설정하였고, Post Syringe(PO)의 용량을 1, 5, 10, 15 mCi로 각각 설정하였다. 그리고 각각의 Matrix size를 32 × 32, 64 × 64, 128 × 128, 256 × 256, 512 × 512, 1024 × 1024로 변경하여 값을 비교 평가하였다. Matrix Size에서 동위원소의 용량이 증가할수록 사구체 여과율의 차이는 최대 52.95%에서 최소 16.67%로 점차 감소하였다. Matrix size 변화에 따른 사구체 여과율 값은 128에서 256, 256에서 512, 512에서 1024로 변경 시 2.4%, 0.2%, 0.2%로 유사하게 나타났으나, 32에서 64, 64에서 128로 변경 시 54.3 %, 39.43%로 GFR 값의 차이가 발생하였다. 마지막으로, 현재 사용 중인 256 Matrix, Pre syringe 15 mCi의 GFR 값을 기준으로 32 Matrix, Pre Syringe 15 mCi, Post Syringe 1 mCi 조건에서 82%로 가장 큰 차이가 발생하였고, 64 Matrix, Pre Syringe 30 mCi, Post Syringe 15 mCi의 조건에서 0.2%로 유사한 결과 값을 나타내었다. 본 논문을 통해 ^99mTc-DTPA Renal Dynamic Scan에서 Gates 공식을 이용해 사구체 여과율을 측정할 때, 동위원소의 용량과 Matrix Size 변화에 따라 사구체 여과율 측정에 영향이 있음을 확인하였다. 그러므로 각 병원에서 이를 적용해 GFR을 측정할 때 적절한 Parameter를 적용해서 검사의 유용성을 높아야 한다고 생각한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.60-64
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• 1995

The conventional neural network models are a parody of biological neural structures, and have very slow learning. In order to emulate some dynamic functions, such as learning and adaption, and to better reflect the dynamics of biological neurons, M.M. Gupta and D.H. Rao have developed a 'dynamic neural model'(DNU). Proposed neural unit model is to introduce some dynamics to the neuron transfer function, such that the neuron activity depends on internal states. Integrating an dynamic elementry processor within the neuron allows the neuron to act dynamic response Numerical examples are presented for a model system. Those case studies showed that the proposed DNU is so useful in practical sense.

• Communications for Statistical Applications and Methods
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• 제31권1호
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• pp.87-104
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• 2024

Most functional magnetic resonance imaging (fMRI) studies in resting state have assumed that the functional connectivity (FC) between time series from distinct brain regions is constant. However, increased interest has recently been in quantifying possible dynamic changes in FC during fMRI experiments. FC study may provide insight into the fundamental workings of brain networks to brain activity. In this work, we focus on the specific problem of estimating the dynamic behavior of pairwise correlations between time courses extracted from two different brain regions. We compare the sliding-window techniques such as moving average (MA) and exponentially weighted moving average (EWMA), dynamic causality with vector autoregressive (VAR) model, dynamic conditional correlation (DCC) based on volatility, and the proposed alternative methods to use differencing and recursive residuals. We investigate the properties of those techniques in a series of simulation studies. We also provide an application with major depressive disorder (MDD) patient fMRI data to demonstrate studying dynamic correlations.

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.325-328
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• 2006

• 대한인간공학회지
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• 제34권4호
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• pp.313-326
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• 2015

Objective: The objective of this research is to quantitatively analyze muscle activities of arm and shoulder, according to direction in various types of one-handed manual material handling, based on surface electromyography. Background: Workers in industrial sites frequently carry out one-handed manual material handling using arm and shoulder muscles. Therefore, chronic load and accumulated fatigue occur to arm and shoulder muscles, which becomes a main cause of upper arm and shoulder musculoskeletal disorders. The shoulder muscles have widely range of motion, and complex interactions take place among various muscles including rotator cuff muscles. In this regard, research on interactions among should muscles, according to such various dynamic motions, is required. Method: Ten male subjects in their 20s participated in this research. This research considered upward, downward, leftward, rightward, forward and backward directions and fourteen muscles around arm and shoulder (biceps brachii and trapezius, etc.) as independent variables. The mean muscle activity was set as the dependent variable. This research extracted $4^{th}{\sim}7^{th}$ repetition signals according to ten times of repetitive muscle contraction, and analyzed the muscle activity concerned using the envelope detection technique. Results: The mean muscle activity of upward direction was analyzed highly statistically significant. The reason is that the effect of gravity works to arm and shoulder muscles. Also, it is conjectured that deformation of coracoacromial ligament was caused, and its contact pressure increased, due mainly to the shoulder flexion, and therefore load was analyzed high. Muscle activity was analyzed significantly low, according to concentric ballistic motion used in the concentric contraction phase by storing elastic energy in the eccentric contraction phase with a motion to bring the weight to the front of subject's body as to downward, leftward and backward directions. Because, elbow joint's flexion-extension motions mainly occurred, biceps brachii was analyzed high muscle activity as the prime mover. Conclusion: The information on the quantitative load of muscles can be applied to ergonomic work design for one-handed manual material handling to minimize muscle load. Application: This research has effectively identified muscle activity according to dynamic contraction by applying an envelope detection technique. The results can be used for ergonomic work design to minimize muscle load during the one-handed manual material handling, according to each direction. The research results are expected to be used for musculoskeletal disorder prevention and physiotherapy in the rehabilitation medical field, based on the muscle load of arm and shoulder in various directions.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4397-4402
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• 2011

The NF-${\kappa}B$ system of transcription factors plays a crucial role in inflammatory diseases, making it an important drug target. We combined quantitative structure activity relationships for predicting the activity of new compounds and quantitative dynamic models for the NF-${\kappa}B$ network with intracellular concentration models. GFA-MLR QSAR analysis was employed to determine the optimal QSAR equation. To validate the predictability of the $IKK{\beta}$ QSAR model for an external set of inhibitors, a set of ordinary differential equations and mass action kinetics were used for modeling the NF-${\kappa}B$ dynamic system. The reaction parameters were obtained from previously reported research. In the IKKb QSAR model, good cross-validated $q^2$ (0.782) and conventional $r^2$ (0.808) values demonstrated the correlation between the descriptors and each of their activities and reliably predicted the $IKK{\beta}$ activities. Using a developed simulation model of the NF-${\kappa}B$ signaling pathway, we demonstrated differences in $I{\kappa}B$ mRNA expression between normal and different inhibitory states. When the inhibition efficiency increased, inhibitor 1 (PS-1145) led to long-term oscillations. The combined computational modeling and NF-${\kappa}B$ dynamic simulations can be used to understand the inhibition mechanisms and thereby result in the design of mechanism-based inhibitors.

• 정보보호학회논문지
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• 제29권3호
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• pp.519-529
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• 2019

지능화된 안드로이드 악성코드는 안티바이러스가 탐지하기 어렵도록 악성행위를 숨기기 위하여 다양한 분석 회피 기법을 적용하고 있다. 악성코드는 악성행위를 숨기기 위하여 백그라운드에서 동작하는 컴포넌트를 주로 활용하고, 자동화된 스크립트로 악성 앱을 실행할 수 없도록 activity-alias 기능으로 실행을 방해하고, 악성행위가 발견되는 것을 막기 위해 logcat의 로그를 삭제하는 등 지능화되어간다. 악성코드의 숨겨진 컴포넌트는 기존 정적 분석 도구로 추출하기 어려우며, 기존 동적 분석을 통한 연구는 컴포넌트를 일부만 실행하기 때문에 분석 결과를 충분히 제공하지 못한다는 문제점을 지닌다. 본 논문에서는 이러한 지능화된 악성코드의 동적 분석 성공률을 증가시키기 위한 시스템을 설계하고 구현하였다. 제안하는 분석 시스템은 악성코드에서 숨겨진 컴포넌트를 추출하고, 서비스와 같은 백그라운드 컴포넌트인 실행시키며, 앱의 모든 인텐트 이벤트를 브로드캐스트한다. 또한, 분석 시스템의 로그를 앱이 삭제할 수 없도록 logcat을 수정하고 이를 이용한 로깅 시스템을 구현하였다. 실험 결과 본 논문에서 제안한 시스템을 기존의 컨테이너 기반 동적 분석 플랫폼과 비교하였을 때, 악성코드 구동률이 70.9%에서 89.6%로 향상된 기능을 보였다.

• The Journal of Korean Physical Therapy
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• 제34권5호
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• pp.218-223
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• 2022

Purpose: This study sought to identify the effects of an insole applied for the flexible flat-foot condition on dynamic balance and ankle muscle activities during the Y-balance test (YBT). Methods: Thirteen flexible flat-footed adults and an equal number of normal-footed adults were enrolled. The dynamic balance of the subjects was measured using the YBT, which is a reach test. While they were reaching forward with their foot, the percentage maximum voluntary isometric contraction (MVIC) of the tibialis anterior, peroneus longus and medial and lateral gastrocnemius were measured and analyzed. The flat-footed group then applied the ready-made insoles and underwent the YBT again. A comparison of the distance and muscle activity was conducted using YBT, not only between the flat-footed and control group, but also between the flat-footed group before and after the application of the insole. Results: Between the groups, the anterior reach distance in the flat-footed group was significantly lower, but there were no significant differences observed in the posteromedial and posterolateral directions. With the insole, the reach distance of the flat-footed group was significantly increased in the anterior and posterolateral direction compared to the control group. With the insole, the lateral gastrocnemius activity significantly decreased compared to trials without the insole in the flat-footed group, but there were no significant differences in the other muscles. Conclusion: The insole for flat-footed subjects can maintain the medial arch of the foot, and it may help enhance functional and mechanical dynamic balance in people with flat feet.

• 한국전문물리치료학회지
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• 제28권2호
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• pp.93-100
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• 2021

Background: Lateral epicondylitis (LE) is the most common chronic musculoskeletal conditions of the upper extremity with pain and wrist extension disability. The tendon which is most affected is the extensor carpi radialis brevis (ECRB). Previous study evaluated the effect of taping technique on patient with LE, but no study investigated the changes of electromyography (EMG) on ECRB when using dynamic taping (DT) technique. Objects: The aim of this study was to investigate the effect of DT technique using dynamic tape on muscle activity of ECRB during wrist isometric extension, isotonic extension and flexion. Methods: Twenty-one healthy subjects volunteered to participate in this study. Subjects were instructed to perform wrist isometric extension, isotonic extension and flexion without and with DT on origin area of ECRB. Wrist isometric extension was performed at 75%, 50% and 25% (%maximal voluntary contraction force), respectively, based on maximum contraction force. Isotonic extension and flexion test used dumbbell. EMG data was collected from ECRB. Results: EMG of ECRB were statistically significant decrease in wrist isotonic extension after DT (p < 0.05). Significant increase in wrist isometric extension during 25% and 50% force task (p < 0.05). Conclusion: This study applied DT technique to suppress the wrist extensor muscles in 21 healthy adults in their twenties. Change in muscle activity was compared in the ECRB muscle during wrist isometric extension, isotonic extension and flexion task. Based on the results of this study, the DT technique applied to the wrist and forearm area can reduce the load on the wrist extensors when the wrist performs various movements during daily life movements or repetitive tasks, and by using these effects, excessive stress is applied to tennis elbow patients.