• Title/Summary/Keyword: A level-set method

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Effect of Backrest Height on Biomechanics Variables During VDT (Visual Display Terminal) Work (VDT 작업 시 의자 등받이 높이가 생체역학적 변인에 미치는 영향)

  • Jinjoo Yang;Sukhoon Yoon;Sihyun Ryu
    • Korean Journal of Applied Biomechanics
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    • v.33 no.1
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    • pp.1-9
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    • 2023
  • Objective: This study identifies the difference among the heights of a chair's backrest (High, Mid, No), the biomechanical changes chair users undergo over time, and the variables that can measure musculoskeletal disorders, eventually providing information on the appropriate type of backrest. Method: Eleven healthy subjects in their 20s and 30s who had no experience with musculoskeletal disorders or surgical operations within the last 6 months participated in this study. Computer typing tasks were randomly designated and performed according to the type of chair backrest, and evaluation was performed for Flexion-Relaxation Ratio (FRR) analysis after the computer typing tasks. This study used eight infrared cameras (sampling rate: 100 Hz) and nine-channel electromyography (sampling rate: 1,000 Hz). ANOVA with repeated measures was conducted to verify the results, with the statistical significance level being α = .05. Results: Although there was no significant difference in craniovertebral angle (CVA), this study showed time and interaction effects depending on the height of the backrest (p<.05). When working without the backrest, the head-spine angle was lower compared to the chairs with backrest, based on the computer work. As for the head angle, the higher the back of the chair was, the less the head flexion and the body angle became, whereas the body flexion became less when there was a backrest. In addition, the body flexion increased over time in all types of backrests (p<.05). The muscle activity of the upper body tended to be high in the high backrest chair. On the other hand, a lower muscle activity was found with a low backrest. Conclusion: These results show that a chair is more ergonomic when the body angle is correctly set without bending and when it is supported by a low backrest. Accordingly, this study determines that the backrest affects shoulder and neck musculoskeletal disorders during typing and that medium-height backrest chairs can help prevent musculoskeletal disorders, contrary to the expectation that high-backrest chairs are preferable.

Analysis and study of Deep Reinforcement Learning based Resource Allocation for Renewable Powered 5G Ultra-Dense Networks

  • Hamza Ali Alshawabkeh
    • International Journal of Computer Science & Network Security
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    • v.24 no.1
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    • pp.226-234
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    • 2024
  • The frequent handover problem and playing ping-pong effects in 5G (5th Generation) ultra-dense networking cannot be effectively resolved by the conventional handover decision methods, which rely on the handover thresholds and measurement reports. For instance, millimetre-wave LANs, broadband remote association techniques, and 5G/6G organizations are instances of group of people yet to come frameworks that request greater security, lower idleness, and dependable principles and correspondence limit. One of the critical parts of 5G and 6G innovation is believed to be successful blockage the board. With further developed help quality, it empowers administrator to run many systems administration recreations on a solitary association. To guarantee load adjusting, forestall network cut disappointment, and give substitute cuts in case of blockage or cut frustration, a modern pursuing choices framework to deal with showing up network information is require. Our goal is to balance the strain on BSs while optimizing the value of the information that is transferred from satellites to BSs. Nevertheless, due to their irregular flight characteristic, some satellites frequently cannot establish a connection with Base Stations (BSs), which further complicates the joint satellite-BS connection and channel allocation. SF redistribution techniques based on Deep Reinforcement Learning (DRL) have been devised, taking into account the randomness of the data received by the terminal. In order to predict the best capacity improvements in the wireless instruments of 5G and 6G IoT networks, a hybrid algorithm for deep learning is being used in this study. To control the level of congestion within a 5G/6G network, the suggested approach is put into effect to a training set. With 0.933 accuracy and 0.067 miss rate, the suggested method produced encouraging results.

The Extreme Value Analysis of Deepwater Design Wave Height and Wind Velocity off the Southwest Coast (남서 해역 심해 설계 파고 및 풍속의 극치분석)

  • Kim, Kamg-Min;Lee, Joong-Woo;Lee, Hun;Yang, Sang-Yong;Jeong, Young-Hwan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.245-251
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    • 2005
  • When we design coastal and harbol facilities deepwater design wave and wind speed are the important design parameters. Especially, the analysis of these informations is a vital step for the point of disaster prevention. In this study, we made and an extreme value analysis using a series of deep water significant wave data arranged in the 16 direction and supplied by KORDI real-time wave information system ,and the wind data gained from Wan-Do whether Station 1978-2003. The probability distributions considered in this characteristic analysis were the Weibull, the Gumbel, the Log-Pearson Type III, the Normal, the Lognormal, and the Gamma distribution. The parameter for each distribution was estimated by three methods, i.e. the method of moments, the maximum likelihood, and the method of probability weight moments. Furthermore, probability distributions for the extreme data had been selected by using Chi-square and Kolmogorov-Smirnov test within significant level of 5%, i,e. 95% reliance level. From this study we found that Gumbel distribution is the most proper model for the deep water design wave height off the southwest coast of Korea. However the result shows that the proper distribution made for the selected site is varied in each extreme data set.

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An Analysis of Key Words Related to Traditional Korean Medicine Using Big Data of Two Search Engines (2대 포털사이트 빅데이터를 이용한 한방관련 키워드 분석)

  • Ahn, Jung-Yun;Keum, Ga-Jeong;Jang, Ah-Ryeong;Song, Ji-Chung
    • The Journal of Korean Medical History
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    • v.30 no.2
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    • pp.45-61
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    • 2017
  • Objectives : This research aims to investigate the consumer's interest in the Korean Medicine (KM) industry by using Google-trends and Naver-Data lab. A quick and uncomplicated way for those who are already involved with KM industry but do not have expertise in utilizing Big-data searches, is introduced. Methods : 'Direct keyword' was set by FGI (Focus Group Interview) and 'Detailed keyword' was set by using relevant word search and autocomplete search functions in the search engine. By inquiring Naver-Data lab, keyword search volumes are compared by age and sex, date range, and originating region of the researcher. It is possible to determine whether the data is reliable or authentic through examining the associated query. Selected direct keywords used through FGI (Focus Group Interview) were 'Acupuncture', 'Herbal Medicine', 'Cupping', 'Musculoskeletal Disease', 'Diet', and 'Stemina'. Based on these keywords, the following results were derived from the keyword analysis. Results : From August 2016, there was a noticeable surge of interest in men's 'Cupping'. The search for 'Diet' increased in the second quarter of 2016 from all ages. The search volume of 'Stemna' for individuals in their 20s is higher than that of those in their 30s or 40s'. Researchers from the region of Chungcheongbuk-do had a higher level of interest in analgesics and less interest in Korean Medicine. There is a greater interest in the KM market from European countries and America, than from Korea, China, and other Asian countries. Discussion : Despite the limitations of the research, it is meaningful to introduce a quick and easy data search method to compare information by age, sex, and region. Conclusion : The future of research into Korea Medicine and this market is confirmed by our data results which indicate interest from Europe, the United States, and other western countries, but less interest from Korea, China and other Asian countries.

Research Trends and Problems on Cultivation Practice of Daesoonjinrihoe (대순진리회 수행 연구의 경향과 과제)

  • Cha, Seon-keun
    • Journal of the Daesoon Academy of Sciences
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    • v.24_1
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    • pp.315-349
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    • 2014
  • This paper was carried out to bring the researches on Cultivation Practice of Daesoonjinrihoe which have been at a standstill after analyzing the directions of studies on Cultivation Practice and diagnosing its problems, in addition to that, the paper was also conducted in a way of discussing the research directions in the future. This work enables scholars who have interests in Daesoon Thoughts to easily comprehend over the length and breadth of Cultivation Practice of Daesoonjinrihoe as well as help them understand what level of researches regarding Cultivation Practice has been demanded. Furthermore, this paper will be a step-stone for scholars to ponder how and on what perspective they approach a wide variety of studies on Daesoon Thoughts. The problems reflected on the previous researches on Cultivation Practice are summarized as follows: first, except a few researches in general, problem recognition, research target, style, method, and content are not diverged from the frame defined by Jang Byeong-Gil, who set it up in Daesoon Religion and Thought (Daesoon Jonggyo Sasang) in 1989. Proliferating overlapped researches without developing problem awareness is of great concern. And such researching climate has gradually set in. Secondly, there are numerous researches intending to reveal the researcher's forceful attitude implying faith. Thirdly, most of the previous researches neglect to focus on defining the range of researches. Fourthly, when defining concepts, more thorough insight is needed. Lastly, the researches on analysing symbols and attempting signification analysis are relatively few, only to find many errors. To solve these problems, this paper suggests to develop theories which back up Cultivation Practice by researching on the fields of theory of mind-nature(心性), theory of mind-qi(心氣), theory of pain, Religious Ethics, viewpoint of God/gods, and psychology. Secondly, all the symbols and meanings of elements shown in Cultivation Practice need analyzing more elaborately sophisticatedly and more in-depth. In order to fulfil this goal, by adapting the recent trends of historical studies, it is essential to attempt to engraft Cultivation Practice of Daesoonjinrihoe on cultural phenomena, to analyze thick layers of meanings beneath its surface, to interpret differently, utilizing various perspectives such as focusing on the gender problems, and to extract true meanings out of Cultivation Practice by analyzing everyday events which can occur in real cultivation practices. Thirdly, the terms and concepts regarding Cultivation Practice base the principle themselves. Fourthly, by utilizing methodology of comparative studies on religions, the comparative researches on cultivation practice of different religious traditions are also needed. Lastly, the history of aspects on Cultivation Practice such as transition of mantras, processes which have been conducted through proprieties of prayer and training should be collected and classified. In this context, this work is very important since it helps understand the aspects of transition of originality and characteristics in Cultivation Practice of Daesoonjinrihoe according to passage of time.

A Study of Hierarchical Policy Model of Policy-based Integrated Security Management for managing Heterogeneous Security Systems (이종의 보안시스템 관리를 위한 정책 기반의 통합보안관리시스템의 계층적 정책모델에 관한 연구)

  • Lee, Dong-Yeong;Kim, Dong-Su;Jeong, Tae-Myeong
    • The KIPS Transactions:PartC
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    • v.8C no.5
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    • pp.607-614
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    • 2001
  • With a remarkable growth and expansion of Internet, the security issues emerged from intrusions and attacks such as computer viruses, denial of services and hackings to destroy information have been considered as serious threats for Internet and the private networks. To protect networks from those attacks, many vendors have developed various security systems such as firewalls, intrusion detection systems, and access control systems. However, managing those systems individually requires too much work and high cost. Thus, in order to manage integrated security management and establish consistent security management for various security products, the policy model of PN-ISMS (Policy Based Integrated Security Management System) has become very important. In this paper, present the hierarchical policy model which explore the refinement of high-level/conceptual policies into a number of more specific policies to form a policy hierarchy. A formal method of policy description was used as the basis of the mode in order to achieve precision and generality. Z-Notation was chosen for this propose. The Z-Notation is mathematical notation for expressing and communicating the specifications of computer programs. Z uses conventional notations of logic and set theory organized into expressions called schemas.

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Evaluation on Riding comfort of A Passenger with Various Surface Textures of Concrete Pavement in Tunnels (터널 내 콘크리트포장 표면처리공법 별 탑승자의 주행쾌적성 평가)

  • Lee, Kyungbae;Lee, Jaehoon;Sohn, Duecksu;Kwon, Soonmin
    • International Journal of Highway Engineering
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    • v.16 no.5
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    • pp.155-164
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    • 2014
  • PURPOSES : The purpose of this article is to compare and evaluate the riding comfort of a passenger in tunnels depending on different surface textures of concrete pavement. METHODS : Evaluation of riding comfort is conducted at 17 sections, which have different surface texture such as transverse tinned(TT), longitudinal tinned(LT) and diamond grinded(DG). A triaxial accelerometer was set up on the passenger seat surface of the test vehicle to measure vibrations of an occupant, then the effects of vibration on comfort and health were evaluated by ISO 2631. And microphones were installed at passenger's ears height to measure sound pressure level(SPL) in the test vehicle. Additionally, a surface microphone was installed on the inside of wheel arch to evaluate noise between tire and pavement by NCPX method. All tests were conducted cruising at 100km/h. RESULTS : The results of all tests are as follows. First, both vibration magnitudes for comfort and for health in LT and DG sections are almost same and they represent lower than those in TT sections. Second, the average SPL of DG shows the lowest decibels among them. And third, it is founded that interior noise is significantly affected by noise between tire and pavement. CONCLUSIONS : It may be concluded that DG can provide more excellent riding comfort to passenger than LT or TT. Therefore, it is necessary to consider applying DG to existing pavement surface to improve surface condition when the driving environment especially requires riding comfort like a long tunnel.

Photogrammetric Analysis of Attractiveness in Indian Faces

  • Duggal, Shveta;Kapoor, DN;Verma, Santosh;Sagar, Mahesh;Lee, Yung-Seop;Moon, Hyoungjin;Rhee, Seung Chul
    • Archives of Plastic Surgery
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    • v.43 no.2
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    • pp.160-171
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    • 2016
  • Background The objective of this study was to assess the attractive facial features of the Indian population. We tried to evaluate subjective ratings of facial attractiveness and identify which facial aesthetic subunits were important for facial attractiveness. Methods A cross-sectional study was conducted of 150 samples (referred to as candidates). Frontal photographs were analyzed. An orthodontist, a prosthodontist, an oral surgeon, a dentist, an artist, a photographer and two laymen (estimators) subjectively evaluated candidates' faces using visual analog scale (VAS) scores. As an objective method for facial analysis, we used balanced angular proportional analysis (BAPA). Using SAS 10.1 (SAS Institute Inc.), the Turkey's studentized range test and Pearson correlation analysis were performed to detect between-group differences in VAS scores (Experiment 1), to identify correlations between VAS scores and BAPA scores (Experiment 2), and to analyze the characteristic features of facial attractiveness and gender differences (Experiment 3); the significance level was set at P=0.05. Results Experiment 1 revealed some differences in VAS scores according to professional characteristics. In Experiment 2, BAPA scores were found to behave similarly to subjective ratings of facial beauty, but showed a relatively weak correlation coefficient with the VAS scores. Experiment 3 found that the decisive factors for facial attractiveness were different for men and women. Composite images of attractive Indian male and female faces were constructed. Conclusions Our photogrammetric study, statistical analysis, and average composite faces of an Indian population provide valuable information about subjective perceptions of facial beauty and attractive facial structures in the Indian population.

Automatic Virtual Platform Generation for Fast SoC Verification (고속 SoC 검증을 위한 자동 가상 플랫폼 생성)

  • Jung, Jun-Mo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.5
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    • pp.1139-1144
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    • 2008
  • In this paper, we propose an automatic generation method of transaction level(TL) model from algorithmic model to verify system specification fast and effectively using virtual platform. The TL virtual platform including structural properties such as timing, synchronization and real-time is one of the effective verification frameworks. However, whenever change system specification or HW/SW mapping, we must rebuild virtual platform and additional design/verification time is required. And the manual description is very time-consuming and error-prone process. To solve these problems, we build TL library which consists of basic components of virtual platform such as CPU, memory, timer. We developed a set of design/verification tools in order to generate a virtual platform automatically. Our tools generate a virtual platform which consists of embedded real-time operating system (RTOS) and hardware components from an algorithmic modeling. And for communication between HW and SW, memory map and device drivers are generated. The effectiveness of our proposed framework has been successfully verified with a Joint Photographic Expert Group (JPEG) and H.264 algorithm. We claim that our approach enables us to generate an application specific virtual platform $100x{\tims}1000x$ faster than manual designs. Also, we can refine an initial platform incrementally to find a better HW/SW mapping. Furthermore, application software can be concurrently designed and optimized as well as RTOS by the generated virtual platform

A Study on the Improvement of Plastic Boat Manufacturing Process Using TOC & Statistical Analysis (TOC와 통계적 분석에 의한 플라스틱보트 제조공정 개선에 관한 연구)

  • Yoon, Gun-Gu;Kim, Tae-Gu;Lee, Dong-Hyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.1
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    • pp.130-139
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    • 2016
  • The purpose of this paper is to analyze the problems and the sources of defective products and draw improvement plans in a small plastic boat manufacturing process using TOC (Theory Of Constraints) and statistical analysis. TOC is a methodology to present a scheme for optimization of production process by finding the CCR (Capacity Constraints Resource) in the organization or the all production process through the concentration improvement activity. In this paper, we found and reformed constraints and bottlenecks in plastic boat manufacturing process in the target company for less defect ratio and production cost by applying DBR (Drum, Buffer, Rope) scheduling. And we set the threshold values for the critical process variables using statistical analysis. The result can be summarized as follows. First, CCRs in inventory control, material mix, and oven setting were found and solutions were suggested by applying DBR method. Second, the logical thinking process was utilized to find core conflict factors and draw solutions. Third, to specify the solution plan, experiment data were statistically analyzed. Data were collected from the daily journal addressing the details of 96 products such as temperature, humidity, duration and temperature of heating process, rotation speed, duration time of cooling, and the temperature of removal process. Basic statistics and logistic regression analysis were conducted with the defection as the dependent variable. Finally, critical values for major processes were proposed based on the analysis. This paper has a practical importance in contribution to the quality level of the target company through theoretical approach, TOC, and statistical analysis. However, limited number of data might depreciate the significance of the analysis and therefore it will be interesting further research direction to specify the significant manufacturing conditions across different products and processes.