• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.478-480
• /
• 2008

On this paper, digitally controlled push-pull dc-dc converter and dc-ac inverter for induction motor control are presented, which is used one DSP(digital signal processor). This system has 12V battery input for the push-pull converter, and the push-pull converter generates 300V output for induction motor inverter input. In order to compensate the push-pull converter, the transfer function of push-pull converter is derived and digital PI compensator is adapted. Through bode diagram, stability of digital controlled push-pull converter is analyzed. To verify the proposed system, digital simulation of the induction motor drive using digital push-pull converter are performed.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10b
• /
• pp.1083-1086
• /
• 2000

최근 무선 인터넷의 보급과 더불어 다양한 기능이 요구되고 있으며, 특히 WAP(Wireless Application Protocol)상에서 지원되는 Push 서비스의 요구가 늘어나고 있다. 본 논문에서는 무선 프로토콜인 WAP상에서 사용하는 푸시(push) 메시지의 보다 쉬운 구현을 위해 Push 서비스의 구조와 동작 원리를 소개하고 푸시 컨텐츠 생성기(Push Content Generator)의 구조와 설계에 대해 기술한다.

• 한국정보교육학회:학술대회논문집
• /
• 2005.08a
• /
• pp.357-366
• /
• 2005

본 연구는 웹 기반 협동학습 환경에서 Push기능이 학업성취도, 학습동기에 미치는 영향을 알아보고자 하였다. 이러한 목적을 달성하기 위한 연구 문제는 다음과 같았다. 1. 웹 기반 협동학습에서 Push 기능에 따른 집단 간의 학업성취도에 미치는 효과에 차이가 있는가? 2. 웹 기반 협동학습에서 Push 기능에 따른 집단 간의 학습동기에 미치는 효과에 차이가 있는가? 3. 웹 기반 협동학습 환경에서 Push 기능과 학습자의 학습능력 간에 상호작용 효과가 있는가? 이러한 연구 문제를 검증하기 위하여 웹 기반 협동학습을 위한 웹 게시판을 제작하였다. 본 실험을 위한 교과와 단원은 초등학교 사회과 4학년 1학기 2단원 '우리 시 도의 발전하는 경제'였다. 사전 검사를 통해 동질성이 확인된 충북 음성군 소재 공립 초등학교 4학년 2개 학급의 36명의 학습자를 대상으로 실험을 실시하였다. 학습자들은 동일한 협동학습 환경에서 Push 기능을 선택적으로 제공받았다. 실험처치에서 얻은 검사결과를 분석하기 위하여 SPSS 12.0 for Windows를 사용하여 이원변량분석(two-way ANOVA)을 실시하였으며 유의수준은 .05로 하였다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 웹 기반 협동학습에서 Push 기능에 따른 집단 간 학업성취도 차이가 없었다. 둘째, 웹 기반 협동학습에서 Push 기능에 따른 학습동기가 차이가 있었다. 즉, Push 기능 적용 집단이 학습동기에서 효과적이었다. 셋째, 웹 기반 협동학습에서 학업성취도와 학습동기는 Push 기능과 학습자의 학습능력수준(상 하) 간의 상호작용 효과가 없었다. 결론적으로, 웹 기반 협동학습에서 Push 기능은 학습동기에서 효과적이라 할 수 있다.

• Journal of Advanced Navigation Technology
• /
• v.6 no.1
• /
• pp.52-62
• /
• 2002

Electrical characteristics of two types of 20 GHz Push-Push GaAs MESFET dielectric resonator oscillators having Wilkinson and T-junction power combiners for the output stage have been investigated. The Push-Push oscillator for suppressing fundamental frequency 10 GHz and enhancing 20 GHz has been designed and realized in microstrip configuration on 20 mil thick RT-Duroid(${\varepsilon}_r$=2.52) teflon substrate. Two different types of power combiners, T-junction and Wilkinson, have been considered. Whenever one type of the combiners has been adopted for the output circuit, output power, phase noise and fundamental frequency suppression characteristics of the oscillator have been measured. When the Wilkinson power combiner was used, a maximum output power of 5.67 dBm, a phase noise of -105.5 dBc/Hz at an offset frequency of 100 kHz and a fundamental frequency suppression of -29.33 dBc have been measured. When the T-junction power combiner was used, a maximum output power of -1.17 dBm, a phase noise of -102.2 dBc/Hz at an offset frequency of 100 kHz and a fundamental frequency suppression of -17.84 dBc have been measured.

• Physical Therapy Korea
• /
• v.29 no.2
• /
• pp.117-123
• /
• 2022

Background: Push-up are effective exercises for shoulder stability. Previous studies have documented the effects of support plane and hand position and width on muscle activities during a push-up. Objects: This study aimed to investigate the changes in muscle activities in the upper extremity when performing the standard and the knee-flexed push-up with different hand shapes. Methods: A total of twenty-six healthy males participated in this study. Three different hand shapes (finger abduction, finger adduction, and fists) and two types of push-up posture (standard and knee-flexed push-up) were set as the independent variables. Electrograms were used to measure the muscle activity of the upper trapezius (UT), triceps brachii (TB), pectoralis major (PM), and serratus anterior (SA). Each participant performed the randomly assigned push-up to the sound of the metronome. The mixed-effect linear regression model was used to detect the changes in muscle activities after changing the hand shape and push-up posture. Statistical significance was set at α = 0.05. Results: The UT muscle activity was statistically significantly higher when performing push-up with fists than finger abduction (p = 0.035) or finger adduction (p = 0.044). During the standard push-up, the muscle activity in all muscles was that the push-up with fists showed the highest muscle activity compared to the finger abduction (p < 0.01) and finger adduction (p < 0.01). Regardless of the shape of the hand, UT had the lowest muscle activity compared to other muscles (p < 0.001). In contrast, the SA muscle had the highest muscle activity among four muscles during the standard push-up. Conclusion: Based on the results of this study, we suggest hand shape is related to the difficulty level of push-up either in the standard or the knee-flexed push-up, especially in the push-up with fists. In addition, knee push-up can be recommended as shoulder muscle-strengthening exercises for individuals with low shoulder muscle strength.

• Journal of the Korea Society of Computer and Information
• /
• v.15 no.6
• /
• pp.37-48
• /
• 2010

In general, an HTTP server sends information in response to requests from clients. Since it does not support active information delivery to clients, it can not efficiently provide the rapidly changing information to clients. Overcoming this shortcoming of the HTTP protocol, the technology known as server push enables the HTTP server to actively provide information to clients without explicit requests from clients. Adobe BlazeDS is a web server supporting the server push technology, helping users to develop web-based push applications. Unfortunately, since the BlaseDS server have no functions of filtering the information to be pushed according to various types of users, there are difficulties in developing push applications handling various situations in a efficient way. In this paper, to support effective development of push applications on BlazeDS we present the methods of adding a message filtering facility to BlazeDS and utilizing it. According to the filtering request of clients, the message filtering facility modifies information to be pushed, sending the modified information to the clients. The extended BlazeDS server with the message filtering facility provides environments to easily develop push services customized for various clients with their own situations.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.1
• /
• pp.36-42
• /
• 2018

This study was to investigate the difference of muscle activities in trunk, upper arm, and shoulder during push-up exercise based on 3 types of different arm position(posterior position, PP; normal position, NP; and anterior position, AP) and to provide effective push-up arm position for each muscle development. Fifteen healthy males(age, $21.5{\pm}0.5years$; height, $172.7{\pm}1.0cm$; body mass, $70.5{\pm}1.3kg$; shoulder width, $42.3{\pm}0.6cm$; and BMI, $23.6{\pm}0.5kg/m^2$) participated in this study. PP, NP, and AP of the arm were used to conduct push-up exercise and 8 muscles(deltoideus p. acromialis: DA; pectoralis minor: PMI; pectoralis major: PMA; serratus anterior: SA; biceps brachii: BB; triceps brachii: TB; latissimus dorsi: LD; and infraspinatus: IS) of right side were selected to measure muscle activities. Total 9 counts of push-up exercise were conducted and EMG data signals of 5-time(from $3^{th}$ to $7^{th}$) push-up movement were used for measuring muscle activities. PP push-up exercise showed that there was a significantly higher muscle activity of DA, PMI, PMA, SA, BB, LD, and IS(p<.05) and AP push-up exercise showed a significantly higher TB activity(p<.05). It would be suggested that different arm position evokes various muscle activities when conducting push-up exercise. PP would be the best push-up arm position for inducing various trunk, upper arm, and shoulder muscle activities compared to NP and AP.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.1
• /
• pp.36-44
• /
• 2005

A push pull hood system is frequently applied to control contaminants evaporated from an open surface tank in recent years. Efficiency of push pull hood system is affected by various parameters, such as cross draft, vessel shapes, size of tanks surface, liquid temperature, and so on. Among these, velocity of cross draft might be one of the most influencing factor for determining the ventilation efficiency. To take account of the effect of cross draft velocities over 0.38m/s, a flow adjustment of ${\pm}$20% should be considered into the push and +20% into the pull flow system Although there are many studies about the efficiency evaluation of push pull hood system based on CFDs(Computational Fluid Dynamics) and experiments, there have been no reports regarding the influence of velocities and direction of cross-draft on push-pull hood efficiency. This study was conducted to investigate the influence of cross draft direction and velocities on the capture efficiency of the push-pull ventilation system. Smoke visualization method was used along with mock-up of push-pull hood systems to verify the ventilation efficiency by experiments. When the cross-draft blew from the same origins of the push flows, the efficiency of the system was in it's high value, but it was decreased significantly when the cross-draft came from the opposite side of push flows Moreover, the efficiency of the system dramatically decreased when the cross-draft of open surface tank was faster than 0.4m/s.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.4
• /
• pp.559-566
• /
• 2002

n this paper, we propose a WBI(Web Based Instruction) for individualized learning using push and pull technologies with WWW(World Wide Web). As well as push End pull technologies, the proposing system is implemented with JSP(Java Server Page) and JDBC(Java Database Connectivity) of java technologies based on the client/server envirionments for the purpose of providing practical lectures to students.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.1033-1034
• /
• 2015

A message transmission method in Push fashions over the Internet has a limit repidly to manage task and support system in a remote control site that has received a risk information. This paper proposes a push notification structure based on the quality of service(QoS) in order to send the diversity disaster informations toward the remote site. As the proposed structure accommodated the previous heterogeneous system, it provides internet services.