• Title/Summary/Keyword: Level Set method

Search Result 1,481, Processing Time 0.032 seconds

Overhand Grip or Underhand Grip, which one is more Effective on Conventional Deadlift Movement? (오버핸드 그립과 언더핸드 그립, 무엇이 컨벤셔널 데드리프트에 효과적일까?)

  • Kim, Jaeho;Yoon, Sukhoon
    • Korean Journal of Applied Biomechanics
    • /
    • v.31 no.2
    • /
    • pp.133-139
    • /
    • 2021
  • Objective: This study aims to verify the conventional deadlift motions using by two different grips, thereby elucidating the grounds for effective training methods that can minimize the risk of injury. Method: Total of 18 healthy young adults were recruited for this study (age: 25.11±2.19 yrs., height: 175.67±5.22 cm, body mass: 78.5±8.09 kg, 1-RM: 125.75±19.48 kg). All participants were asked to perform conventional deadlift with two types of grips which are overhand grip (OG) and underhand grip (UG). In each grip, participant perform the deadlift with 50% and 80% of the pre-measured 1-RM. A 3-dimensional motion analysis with 8 infrared cameras and 3 channels of EMG was performed in this study. A two-way ANOVA (group × load) with repeated measure was used for statistical verification. The significant level was set at α=.05. Results: There were significant differences in grip type and weight on the right shoulder joint, and only significant difference in grip on the left shoulder joint (p<.05). The hip joint ROM was significantly increased as the weight increased in both types of grips on phase 1, while the ROM of hip joint was significantly decreased as the weight increased only in the case of OG on phase 2 (p<.05). In case of the OG, as the weight, increased significantly increased L1 ROM and L3 ROM were revealed on phase 1 and phase 2, respectively (p<.05). Moreover, as the weight increased, UG revealed significantly decreased L5 ROM on phase 1, while both grips showed significantly increased ROM on phase 2 (p<.05). In addition, the erector spinae and the biceps femoris, which are synergist for the motion, showed a significant difference in both types of grip according to the weight (p<.05). The muscle activity ratio of gluteus maximus/biceps femoris showed a significant difference only in the UG according to the weight (p<.05). Conclusion: In conclusion, beginners might be suggested to use the UG for maintaining the neutral state of the lumbar spine and focus on the gluteus maximus muscle, which is the main activation muscle. For the experts, it may recommend alternative use of the OG and UG according to the training purpose to minimize the compensation effect.

A study on national cybersecurity policy agenda in Korea using national cyber capability assessment model (국가 사이버 역량평가 모델을 활용한 국내 사이버안보 정책 의제 도출 연구)

  • Song, Minkyoung;Bae, Sunha;Kim, So-Jeong
    • Journal of Digital Convergence
    • /
    • v.19 no.8
    • /
    • pp.89-100
    • /
    • 2021
  • The National Cyber Capability Assessment(NCCA) could be used as meaningful information for improving national cyber security policy because it provides information on the elements necessary for strengthening national cyber capabilities and the level of each country. However, there were few studies on improving cyber capabilities using the NCCA result in Korea. Therefore, we analyzed the result of National Cyber Power Index(NCPI) conducted by Belfer Center of Harvard Univ. by applying modified-IPA method to derive cybersecurity policy agendas for Korea. As a result, the need to set agendas on surveillance and offensive cyber capability and improve the effectiveness of policy implementation for intelligence and defense was drawn. Moreover, we suggested need for in-depth study of each policy agenda deduced from preceding research data as a future tasks. And it is expected to increase practical use of NCCA for domestic policy analysis by developing and using our own NCCA model which considered analysis framework proposed in this study.

Effects of Interfering Current Stimulation on Vastus Medialis Oblique and Vastus Lateralis Activity and Ratio during Squat Exercise (스쿼트 운동 시 적용된 중주파 전기자극이 안쪽빗넓은근과 가쪽넓은근의 근활성도 및 근활성비에 미치는 영향)

  • Kim, Chung-Yoo
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.9 no.4
    • /
    • pp.283-289
    • /
    • 2021
  • Purpose : The purpose of this study is to investigate the effect of mid frequency electrical stimulation during squat exercise on the muscle activity and muscle activity ratio of vastus medialis oblique and vastus lateralis, and to prepare scientific basic data for exercise intervention using mid frequency electrical stimulation. Methods : This study was conducted with students from University C located in Busan, and among a total of 123 subjects, 12 subjects who complained of knee joint dysfunction between 80 and 90 points using the Kujala patellofemoral score (KPS) were used. All subjects participated in the experiment for 3 days, and MVIC values were measured for normalization of muscle activity values on the first day. For the two days, participants participated in the experiment and performed squat exercise or squat exercise receiving mid-frequency electrical stimulation in random order. Measurements were taken in the squat position immediately after the squat exercise, and muscle activities of vastus medialis oblique and vastus lateralis were measured. The measured data were compared through the dependent t test, and the statistical significance level was set to .05. Results : According to the results of this study, in the case of applying mid-frequency electrical stimulation together in the ratio of vastus medialis oblique and vastus lateralis muscle activity during squat exercise, higher values were observed compared to the case of not applying mid-frequency electrical stimulation together, and statistically significant. Also, when mid-frequency electrical stimulation was applied to both vastus medialis oblique and vastus lateralis activities during the squat exercise, higher values were shown compared to the case where the mid-frequency electrical stimulation was not applied together, but there was no statistically significant difference. Conclusion : The results of this study reported that mid-frequency electrical stimulation provided to vastus medialis oblique increased the muscle activity ratio of vastus medialis oblique and vastus lateralis. Therefore, the improvement of coordination due to the enhancement of the activity of vastus medialis oblique through mid-frequency electrical stimulation will be more helpful in the treatment of patellofemoral pain syndrome patient. In addition, it is hoped that the electrical stimulation method applied to exercise will be widely used.

A Study on Methods of Implementation for the NRF Open Access Policy (한국연구재단 오픈액세스 정책 실행방안 연구)

  • Joung, KyoungHee;Lee, Jae Yun;Chung, EunKyung;Choi, Sanghee
    • Journal of the Korean Society for information Management
    • /
    • v.37 no.4
    • /
    • pp.255-286
    • /
    • 2020
  • This study aims to identify the methods of implementation for the 'National Research Foundation of Korea Open Access 2021(Plan)'. This study covers the methods of implementation in the three following core items: 1) developing the details on the amount, method, and procedures of APC support; 2) proposing methods for facilitating the transition of domestic Korean academic journals to open access journals; and 3) developing methods of entrusting papers to open access repositories. APC support should be guaranteed at a reasonable level. The average or median of APC values for the previous three years will be applied to set the upper limit for support each year. APC support will be provided when the paper is published to open access journals or transitioning journals to open access. Hybrid journals or dual access journals are not included. Support for open access publishing of academic journals in Korea during the transition period will be available for open access journals that have registered for CCL in KJCI or journals that have submitted their application for transitioning to open access. Publishing in hybrid, dual access or subscription-based journals must be accompanied by items related to copyright such as embargo. Research results will be used for the detailed implementation plan of 'NRF OA2021 (Plan)'. They will serve as the base data for the rapid, stable, and sustainable implementation of open access policy in NRF, addressing the Korean domestic academic journal publishing environment and the field of international academic communication.

Exploring the Online Learning Experience of College Students Majoring Physical Education in the COVID-19 Pandemic (코로나-19 팬데믹으로 인한 체육계열 대학생의 원격수업 학습경험 탐색)

  • Lee, Man-Gi;Cho, Eunbyul;Lim, Hyosung
    • Journal of Digital Convergence
    • /
    • v.19 no.1
    • /
    • pp.421-430
    • /
    • 2021
  • The study was conducted to examine the educational experiences and perceptions of college students in the field of physical education as they were taken remote classes in university due to the effects of the social collective infection caused by COVID-19. To achieve the purpose of the study, an online survey was conducted on 278 university students who major in physical education, and the survey questions include the status of remote classes, remote class recognition (preference, and satisfaction level). As for the analysis method, frequency analysis, response sample t-verification, ANOVA, and word-cradle were performed using SPSS 22.0 and R programs, and all significance levels were set at .05. The results from the above research process are as follows. First, in the types of remote classes in the sports category due to COVID-19, video types were used the most in both theoretical and practical classes, and the following was shown as assignment types. The third type was the voice record lecture type for theoretical classes, and the practical class was the video lecture scene. Second, in the remote class preference for the students, both theory and practical classes, video format were the most prefered, followed by video lecture scene and voice lecture type. Third, the analysis of the differences in satisfaction between theoretical and practical classes of the students showed that there was no difference in satisfaction according to the type of class.

Transaction Pattern Discrimination of Malicious Supply Chain using Tariff-Structured Big Data (관세 정형 빅데이터를 활용한 우범공급망 거래패턴 선별)

  • Kim, Seongchan;Song, Sa-Kwang;Cho, Minhee;Shin, Su-Hyun
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.2
    • /
    • pp.121-129
    • /
    • 2021
  • In this study, we try to minimize the tariff risk by constructing a hazardous cargo screening model by applying Association Rule Mining, one of the data mining techniques. For this, the risk level between supply chains is calculated using the Apriori Algorithm, which is an association analysis algorithm, using the big data of the import declaration form of the Korea Customs Service(KCS). We perform data preprocessing and association rule mining to generate a model to be used in screening the supply chain. In the preprocessing process, we extract the attributes required for rule generation from the import declaration data after the error removing process. Then, we generate the rules by using the extracted attributes as inputs to the Apriori algorithm. The generated association rule model is loaded in the KCS screening system. When the import declaration which should be checked is received, the screening system refers to the model and returns the confidence value based on the supply chain information on the import declaration data. The result will be used to determine whether to check the import case. The 5-fold cross-validation of 16.6% precision and 33.8% recall showed that import declaration data for 2 years and 6 months were divided into learning data and test data. This is a result that is about 3.4 times higher in precision and 1.5 times higher in recall than frequency-based methods. This confirms that the proposed method is an effective way to reduce tariff risks.

Rule-base Expert System for Privacy Violation Certainty Estimation (개인정보유출 확신도 도출을 위한 전문가시스템개발)

  • Kim, Jin-Hyung;Lee, Alexander;Kim, Hyung-Jong;Hwang, Jun
    • Journal of the Korea Institute of Information Security & Cryptology
    • /
    • v.19 no.4
    • /
    • pp.125-135
    • /
    • 2009
  • Logs from various security system can reveal the attack trials for accessing private data without authorization. The logs can be a kind of confidence deriving factors that a certain IP address is involved in the trial. This paper presents a rule-based expert system for derivation of privacy violation confidence using various security systems. Generally, security manager analyzes and synthesizes the log information from various security systems about a certain IP address to find the relevance with privacy violation cases. The security managers' knowledge handling various log information can be transformed into rules for automation of the log analysis and synthesis. Especially, the coverage of log analysis for personal information leakage is not too broad when we compare with the analysis of various intrusion trials. Thus, the number of rules that we should author is relatively small. In this paper, we have derived correlation among logs from IDS, Firewall and Webserver in the view point of privacy protection and implemented a rule-based expert system based on the derived correlation. Consequently, we defined a method for calculating the score which represents the relevance between IP address and privacy violation. The UI(User Interface) expert system has a capability of managing the rule set such as insertion, deletion and update.

The Effect of Flipped-PBL on the Communication and Problem Solving Skills (Flipped-PBL이 대학생의 문제해결능력과 의사소통능력에 미치는 영향)

  • Nam, Sunwoo
    • Journal of Christian Education in Korea
    • /
    • v.64
    • /
    • pp.347-368
    • /
    • 2020
  • The purpose of this study was explored the effect of Flipped PBL on Communication and Problem Solving skill of University students. For study, students in the college of education at A University and S University located in Gyeonggi-do were set up 60 students. They majored in Christian education and early childhood education, and the level of education was similar in the same region and department. In the experiment, the comparison group and the experimental group were separated, and data were collected through pre-test before class and post-test after class, followed by analysis covariance(ANCOVA). Between the comparative group performing flipped learning and the experimental group performing flipped PBL, the problem solving ability and communication ability using the flipped PBL averaged 4.28 and the communication ability averaged 4.06. As a result, it was higher than each of the comparison groups, confirming that it had a significant effect. This will be able to present a flipped PBL class design as an alternative method to overcome the limitations of the existing flip learning in a changing classroom situation and to improve the communication and problem solving ability of the learner.

Method of ChatBot Implementation Using Bot Framework (봇 프레임워크를 활용한 챗봇 구현 방안)

  • Kim, Ki-Young
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.15 no.1
    • /
    • pp.56-61
    • /
    • 2022
  • In this paper, we classify and present AI algorithms and natural language processing methods used in chatbots. A framework that can be used to implement a chatbot is also described. A chatbot is a system with a structure that interprets the input string by constructing the user interface in a conversational manner and selects an appropriate answer to the input string from the learned data and outputs it. However, training is required to generate an appropriate set of answers to a question and hardware with considerable computational power is required. Therefore, there is a limit to the practice of not only developing companies but also students learning AI development. Currently, chatbots are replacing the existing traditional tasks, and a practice course to understand and implement the system is required. RNN and Char-CNN are used to increase the accuracy of answering questions by learning unstructured data by applying technologies such as deep learning beyond the level of responding only to standardized data. In order to implement a chatbot, it is necessary to understand such a theory. In addition, the students presented examples of implementation of the entire system by utilizing the methods that can be used for coding education and the platform where existing developers and students can implement chatbots.

3D Printing-Based Ultrafast Mixing and Injecting Systems for Time-Resolved Serial Femtosecond Crystallography (시간 분해 직렬 펨토초 결정학을 위한 3차원 프린팅 기반의 초고속 믹싱 및 인젝팅 시스템)

  • Ji, Inseo;Kang, Jeon-Woong;Kim, Taeyung;Kang, Min Seo;Kwon, Sun Beom;Hong, Jiwoo
    • Korean Chemical Engineering Research
    • /
    • v.60 no.2
    • /
    • pp.300-307
    • /
    • 2022
  • Time-resolved serial femtosecond crystallography (TR-SFX) is a powerful technique for determining temporal variations in the structural properties of biomacromolecules on ultra-short time scales without causing structure damage by employing femtosecond X-ray laser pulses generated by an X-ray free electron laser (XFEL). The mixing rate of reactants and biomolecule samples, as well as the hit rate between crystal samples and x-ray pulses, are critical factors determining TR-SFX performance, such as accurate image acquisition and efficient sample consumption. We here develop two distinct sample delivery systems that enable ultra-fast mixing and on-demand droplet injecting via pneumatic application with a square pulse signal. The first strategy relies on inertial mixing, which is caused by the high-speed collision and subsequent coalescence of droplets ejected through a double nozzle, while the second relies on on-demand pneumatic jetting embedded with a 3D-printed micromixer. First, the colliding behaviors of the droplets ejected through the double nozzle, as well as the inertial mixing within the coalesced droplets, are investigated experimentally and numerically. The mixing performance of the pneumatic jetting system with an integrated micromixer is then evaluated by using similar approaches. The sample delivery system devised in this work is very valuable for three-dimensional biomolecular structure analysis, which is critical for elucidating the mechanisms by which certain proteins cause disease, as well as searching for antibody drugs and new drug candidates.