• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.4
• /
• pp.809-816
• /
• 2007

This paper presents an analysis of the SEMG signal quantitatively and automatically using spike variables : MSF, MSA, MSS, and MSD. The SEMG signals were recorded in three muscle parts, first dorsal interosseus, biceps brachii and abductor policis brevis, from 14 normal subjects. Emphasis was placed on the following 3 points in the experiments. 1) Suggest proper window length to estimate the spike variables 2) Investigate variation of the spike variables to varying %MVC. 3) Investigate variation of the spike variables to the sustained contraction for 30 minutes. Quantitative results were showed and examined in point of practical clinical application.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.6
• /
• pp.1246-1254
• /
• 2009

The reproducibility of initial value and change over time of surface EMG spike variables(MSA, MSF, MSS, MSD) was investigated in the biceps brachii muscle of 11 healthy subjects. Surface EMG signals were recorded during sustained isometric voluntary contractions for 30 seconds at three contraction levels, 20%, 50%, and 80%MVC, respectively. Each contraction was repeated three times in each of three different days for a total of nine contractions and 99 contractions per %MVC level across the eleven subjects. A total of 297 EMG signals across the different trials, days, subjects, and %MVC levels was saved for the subsequent analysis. The degree of reproducibility was investigated using the intraclass correlation coefficient(ICC) and the standard error of the mean(SEM) based upon the analysis of variance(ANOVA), Results for intercept showed higher reproducibility of the spike variables with about 60%-98% ICC than the variable(ARV, MNF) which had been analyzed before in other researches. And results for slope showed poor reproducibility of the spike variables with about 30%-70% ICC and they were comparable with the variables of other researches.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.1
• /
• pp.124-130
• /
• 2018

The EMG amplitude estimator, which has been investigated as an indicator of muscle force, is of high relevance not only in biomechanical studies but also more and more in clinical applications. This paper presents a new approach to estimate surface EMG amplitude by using the mean spike and mean turn amplitude(MSA and MTA) variables. Surface EMG signals, a total of 198 signals, were recorded from biceps brachii muscle over the range of 20-80%MVC isometric contraction and performance of the MSA and MTA variables applied to amplitude estimation of the EMG signals were investigated. To examine the performance, a SNR(signal-to-noise ratio) was computed from each amplitude estimate. The results of the study indicate that MSA and MTA amplitude estimations with first order whitening filter and 300[ms]-350[ms] moving average window length are optimal and show better performance(mean SNR improvement of 6%-15%) than the most frequently used variables(ARV and RMS).

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2000.04a
• /
• pp.17-17
• /
• 2000

The issue of reflow profiling continues to be a complex topic. The pains often associated with profiling can be reduced greatly if certain guidelines are followed and if there is a strong understanding of the variables that can be encountered during the reflow process. This paper shall discuss the appropriate guidelines and trouble shooting methods for reflow profiling, and in particular shall focus upon the benefits of implementing the linear ramp-to-spike profile. Delta T(T) is defined as the variation of temperature found on an assembly during the reflow process. Too large of a T can result in soldering defects, so to combat T a Ramp-Soak-Spike(RSS) reflow profile often is utilized. However, when using a newer-style reflow oven, the T often is minimized or eliminated, thus, the soak zone of the reflow profile becomes an unnecessary step. Because of this, the implementation of a linear Ramp-To-Spike(RTS) reflow profile should be considered. Benefits such as reduced energy costs, reduced solder defects, increased efficiency, improved wetting, and a simplification of the reflow profile process may be experienced when using the RTS profile. Included in this paper are the suggested process parameters for setting up the RSS and RTS profiles and the chemical and metallurgical reactions that occur at each set point of these profiles. The paper concludes with a discussion and pictures of several profile-related defects. Each of these defects is described, analyzed, and instructions are given for troublshooting these defects.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.1
• /
• pp.1-18
• /
• 2005

The purpose of this study was to evaluate performance characteristics. in the success of team attack during volleyball competition. For this, real game was analyzed using S-VHS video camera for three dimensional cinematography. The contents of this research were receive to set time, set to spike time, setter moving distance, ball position during set and attacker's relative ball position during jump and spike, and open area at spike. Among the various kinematical factors considered in this study, the ball height relative spiker and open area were found to be related to offensive performance. This finding implies that although their direct impact were not significant the other factors could have indirect impact on offensive performance by increasing open area. Thus, receiver, setter, assistant attacker, and main attacker should practice for successful performance in each stage. Lastly, it is necessary to develop kinematic variables to evaluate performance characteristics of players. Further study may consider the best defense position against the attack of the opponent player.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.4
• /
• pp.428-434
• /
• 2021

To study whether the area under the cultivation of Italian ryegrass (IRG) has increased with rise in global temperatures, we investigated the effects of climatic variables on seed productivity in different parts of Gangwon-do, South Korea. Specifically, IRG was cultivated in the western (Gangneung), central (Wonju), and northern (Chuncheon) parts of Gangwon-do. The heading date of IRG in Gangneung was earlier than that in the other regions. Moreover, the values of agronomic traits, including spikelets per spike, grains per spike, and thousand-grain weight, were lower in Chuncheon. However, there were no differences spikelets per spike and grains per spike between Wonju and Gangneung. Additionally, the thousand-grain weight and seed production were higher in Gangneung. Statistical correlation analysis between climatic variables and agronomic traits revealed that the mean daily minimum temperature was positively correlated with seed formation-related traits in April and seed maturity-related traits in May. In the light of rising minimum temperatures in Gangwon-do, Gangneung, Chuncheon and Wonju are suitable areas for IRG cultivation with optimal seed productivity.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.4
• /
• pp.125-134
• /
• 2006

The purpose of this study was to analyze the Biomechanical elements by looking at the differences on the motions of the right and left spikes of right-handed offense volleyball players, using 3D image analysis and force platform. For that purpose, spike motions of six male university volleyball players were recorded three times each using two 16mm high speed cameras and the speed of recording was set at 60 frames/sec. The coordinated raw data was leveled as 6Hz using low pass filtering method and the calculation of 3D coordinates was done by using a DLT (Direct Linear Transformation) method. Also KWON 3D program was used to analyze the variables. Through the experiments and research, the following results were found: That is, in case of the right spike, the required time from the toss to the impact, which affected the success rate of offense showed as longer and on the take-off, the exact timing to touch the ball was longer because the pace between right and left feet was wider, and also after the jump, the distance between the feet indicated shorter, than the left. In addition, the degree of somersault and horizontal adduction of shoulder joint was smaller and the degree of medial rotation of shoulder joint showed bigger than the left, so it indicated that it was not centered on the body, but by the arm with an axis of shoulder using a swing motion. After the impact, the speed of the ball indicated slower compared to the left spike.

• Korean Journal of Applied Biomechanics
• /
• v.13 no.3
• /
• pp.241-252
• /
• 2003

The purpose of this study was to evaluate performance characteristics in the success of team attack during volleyball game. Three dimensional analysis was performed with games of business teams. Analyzed variables were followed by the movement distance of a setter when A-quick was occurred, the position during the spike, the possibility area during the attack, the right and left distance of the assistance attacker, the distance between attacker and blocker, and the distance between blockers each others. 1. It is recommended that the movement distance of the setter be decreased in order to make stable set condition. 2. In order to make one person blocking, the formation was to be consisted of the right and left formation which was associated with the progressive attack performance of the assistance attacker. 3. It is useful to widen attack area. Also it is necessary to improve the enhancement of passing the ball against the blocking of an opponent player. Finally, it is necessary to develop kinematic variables to evaluate performance characteristics of players. Further study may consider the best defense position against the attack of the opponent player.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.11 no.7
• /
• pp.569-573
• /
• 2001

An approximate representation of discrete functions {f$_{i,j}\mid$｜i, j=-1, 0, 1, …, N+1}in two variables by a fuzzy system is described. We use the cubic B-splines as fuzzy sets for the input fuzzification and spike functions as the output fuzzy sets. The ordinal number of f$_{i,j}$ in the sorted list is taken to be the out put fuzzy set number in the (i, j) th entry of the fuzzy rule table. We show that the fuzzy system is an exact representation of the cubic spline function s(x, y)=$\sum_{N+1}^{{i,j}=-1}f_{i,j}B_i(x)B_j(y)$ and that the approximation error S(x, y)-f(x, y) is surprisingly O($h^2$) when f(x, y) is three times continuously differentiable. We prove that when f(x, y) is a gray scale image, then the fuzzy system is a smoothed representation of the image and the original image can be recovered exactly from its fuzzy system representation when it is a digitized image.e.

• Korean Journal of Applied Biomechanics
• /
• v.27 no.3
• /
• pp.219-227
• /
• 2017

Objective: The aim of this study was to analyze the effects of bobsleigh shoes on the lower extremity range of motion and start speed lap time and to develop bobsleigh shoes suitable for winter environments and Korean players based on sports science and optimized biomechanical performance. Background: The bobsleigh shoes used in the start section of the sport are one of the most important equipment for improving athletes' performances. Despite the importance of the start section, there are no shoes that are specifically designed for Korean bobsleigh athletes. Thus, Korean athletes have to wear sprint spike shoes instead of bobsleigh shoes to practice the start. Method: The subjects included four bobsleigh athletes from the Gangwon Province Bobsleigh Skeleton Federation. The study selected the bobsleigh shoe type A (company A) and type B (company B). We analyzed the lower extremity range of motion and sprint time (start line to 10 m) using a Motion Analysis System (USA). Results: In the measurement of the time required for the bobsleigh start section (10 m), the type A shoes demonstrated the fastest section record by $2.765{\pm}0.086sec$ and yielded more efficient movements, hip and knee flexion, hip extension, ankle dorsiflexion, plantar flexion, and inversion than the type B shoes. Conclusion: Type A shoes can yield a better performance via effective lower extremity movements in the bobsleigh start section. Application: In the future, functional analysis should be conducted by comparing the upper material properties, comfort, and muscle fatigue of bobsleigh shoes based on the Type A shoes to develop such shoes suitable for Koreans.