• Title/Summary/Keyword: on-off control

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Random Balance between Monte Carlo and Temporal Difference in off-policy Reinforcement Learning for Less Sample-Complexity (오프 폴리시 강화학습에서 몬테 칼로와 시간차 학습의 균형을 사용한 적은 샘플 복잡도)

  • Kim, Chayoung;Park, Seohee;Lee, Woosik
    • Journal of Internet Computing and Services
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    • v.21 no.5
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    • pp.1-7
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    • 2020
  • Deep neural networks(DNN), which are used as approximation functions in reinforcement learning (RN), theoretically can be attributed to realistic results. In empirical benchmark works, time difference learning (TD) shows better results than Monte-Carlo learning (MC). However, among some previous works show that MC is better than TD when the reward is very rare or delayed. Also, another recent research shows when the information observed by the agent from the environment is partial on complex control works, it indicates that the MC prediction is superior to the TD-based methods. Most of these environments can be regarded as 5-step Q-learning or 20-step Q-learning, where the experiment continues without long roll-outs for alleviating reduce performance degradation. In other words, for networks with a noise, a representative network that is regardless of the controlled roll-outs, it is better to learn MC, which is robust to noisy rewards than TD, or almost identical to MC. These studies provide a break with that TD is better than MC. These recent research results show that the way combining MC and TD is better than the theoretical one. Therefore, in this study, based on the results shown in previous studies, we attempt to exploit a random balance with a mixture of TD and MC in RL without any complicated formulas by rewards used in those studies do. Compared to the DQN using the MC and TD random mixture and the well-known DQN using only the TD-based learning, we demonstrate that a well-performed TD learning are also granted special favor of the mixture of TD and MC through an experiments in OpenAI Gym.

Fabrication of passive-aligned optical sub-assembly for optical transceiver using silicon optical bench (실리콘 광학벤치를 사용한 수동정렬형 광송수신기용 광부모듈의 제작)

  • Lee, Sang-Hwan;Joo, Gwan-Chong;Hwang, nam;moon, Jong-Tae;Song, Min-Kyu;Pyun, Kwang-Eui;Lee, Yong-Hyun
    • Korean Journal of Optics and Photonics
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    • v.8 no.6
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    • pp.510-515
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    • 1997
  • Packaging takes an extremely important element of optical module cost due primarily to the added complication of alignment between semiconductor devices and optical fiber, and many efforts have been devoted on reducing the cost by eliminating the complicated optical alignment procedures in passive manner. In this study, we fabricated silicon optical benches on which the optical alignments are accomplished passively. To improve the positioning accuracy of a flip-chip bonded LD, we adopted fiducial marks and solder dams which are self-aligned with V-groove etch patterns, and a stand-off to control the height and to improve the heat dissipation of LD. Optical sub-assemblies exhibited an average efficiency of -11.75$\pm$1.75 dB(1$\sigma$) from the LD-to-single mode fiber coupling and an average sensitivity of -35.0$\pm$1.5 dBm from the fiber and photodetector coupling.

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Anterior Talofibular Ligament and Superior Extensor Ankle Retinaculum Thicknesses: Relationship with Balance

  • Malloy, Brooke;Furrow, David;Cook, Haily;Smoot, Elizabeth;Cash, Lindsey;Aron, Adrian;Jagger, Kristen;Harper, Brent
    • Journal of Korean Foot and Ankle Society
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    • v.23 no.4
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    • pp.173-182
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    • 2019
  • Purpose: This study determined if anterior talofibular ligament (ATFL)/superior extensor ankle retinaculum (SEAR) thicknesses are related to dynamic balance in individuals with chronic ankle instability (CAI). Materials and Methods: The subjects were 14 males and 15 females (age=24.52±3.46 years). Ankle instability was assessed using the Cumberland Ankle Instability Tool (CAIT) with a cut off score of 25 to define two groups. SonoSite MTurbo (Fugifilm Sonosite, Inc.) musculoskeletal ultrasound (MSKUS) unit was used to assess ATFL and SEAR thicknesses. Dynamic balance was measured with the Y Balance Test (YBT) and two NeuroCom balance tests. Results: There were no significant differences in the average ATFL thickness between stable and unstable ankles in those subjects with CAI (0.25±0.03 cm and 0.21±0.05 cm, respectively) or in the SEAR thickness (0.09±0.04 cm and 0.10±0.03 cm, respectively). There were also no significant differences in the right and left ATFL thicknesses (0.23±0.07 cm and 0.21±0.04 cm, respectively) or the SEAR thicknesses (0.09±0.01 cm and 0.09±0.01 cm, respectively) in those without CAI. There were no differences between limbs in composite scores on YBT in those with CAI (p=0.35) and those without CAI (p=0.33). There was a moderate correlation between the left SEAR thickness and the large forward/backward perturbations on the NeuroCom (Natus) motor control test (r=0.51, p=0.006 and r=0.54, p=0.003, respectively). Conclusion: There were no differences in the ATFL/SEAR thicknesses or balance measures between or within the groups, likely because CAI is multi-factorial and related to mechanisms other than tissue changes alone. More sensitive technology and a better definition of the measurement process may provide more definitive results.

TREATMENT OF COMPOSITE RESIN RESTORATION WITH THE AIR ABRASIVE TECHNIQUE (Air abrasive technique을 이용한 복합레진 수복 증례)

  • Lee, Chang-Woo;Jang, Ki-Taeg;Lee, Sang-Hoon;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.4
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    • pp.763-770
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    • 1997
  • The air abrasive technique is a non-mechanical method by which teeth are treated before restoration and stains and calculi are removed from tooth surfaces using the kinetic energy of small particles. The air abrasive technique in dentistry was first introduced in the 1950's with as instrument called 'Airdent'. But, as the main restorative materials of the period were amalgam and gold, and the instrument's inability to control the flow of particles caused the particles to be spread throughout the clinics, widespread use was not possible. In the 1990's, as these techincal problems were solved and more interest in new restorative materials rose in an effort to preserve sound tooth structure, new developements took place in instruments related to the air abrasive technique. The air abrasive technique produces less pressure, vibration and heat that might cause patient discomfort and facilitates the preservation of sound tooth structure. It also reduces the need for anesthesia and is less harmful to the pulp. Other advantages include increase in dentin bonding strength of composite resin, lower possibility of saliva contamination and maintenance of a dry field. But there is not direct contact between the nozzle and the tooth, the operator cannot use his or her tactile sense and must rely solely upon visual input. Other disadvantages are: the tooth preparation depends on the operator's ability; alpha-alumina particles, after bouncing off the tooth surface, cause damage to dental mirrors; the equipment is expensive and takes up a certain amount of space in the clinic. The author conducted case report using the air abrasive technique on patient visiting the Department of Pediatric Dentistry at Seoul National University Dental Hospital and arrived at the following conclusions. 1. The tooth preparation capability of different air abrasive devices varied widely among manufacturers. 2. It was more effective in treating early caries lesions and stains compared to lesions where caries had already progressed to produce soft dentin. 3. The cold stream and noise caused by the evacuation system was a major cause of discomfort to pediatric patients. 4. As there is no direct contact with tooth surface when using the air abrasive technique for tooth preparation, considerable experience and skill is required for proper tooth preparation.

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The remineralization effect of topical fluoride agents using confocal laser scanning microscope on artificial enamel caries aspects of convergence observation (공초점 레이저 주사 현미경을 이용한 우치 인공우식법랑질에서 불소도포 전·후의 재광화 효과에 대한 융합적 관찰)

  • Lee, Min-Sun;Kim, Hyo-Jin
    • Journal of the Korea Convergence Society
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    • v.8 no.6
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    • pp.139-145
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    • 2017
  • The aim of this study was to measure the remineralization effect of APF gel and fluride varnish on artificial enamel caries using CLSM in vitro. The samples were divided into 3 groups: control, 1.23% APF gel, 5% NaF varnish. The specimen surfaces were observed by CLSM and measured average fluorescence of the lesion(AFL). The results were analyzed using one-way ANOVA and Pearson's correlation analysis at a significance level off 0.05(PSWA 18.0, SPSS Inc., USA). There were significant differences between AFL at baseline and 1 day after fluoride application(p<0.05) but there are no significant differences between ${\Delta}$ AFL of all groups (p=0.222). Result of Pearson's correlation analysis, there are no significant correlation between VHN and AFL, but there were significant correlation between AFL at baseline and 1 day after fluoride application(r=0.811, p<0.001). Although AFL decreased after fluoride application, but there was no difference between the groups. In the future, it is necessary to test the oral environment model or in situ experiment supplemented the limitations of this study.

Role of Plant Hormones in the Senescing Detached Leaves of Phaseolus vulgaris (강낭콩 잎의 노화에 있어서 식물 호르몬의 역할)

  • 이동희;서영희;김영상
    • Journal of Life Science
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    • v.7 no.4
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    • pp.308-308
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    • 1997
  • Role of plant hormones on the leaf senescence of Phaseolus vulgaris were investigated by measuring the disassembly of chlorophyll-protein complexes in detached leaves treated with NAA, GA$_{3}$ , or BA. The loss of chlorophyll that was characteristic of leaf senescence induced disassembly of chlorophyll-protein complexed. During dark-induced senescence, PSI complex was rapidly degraded after the early stage, whereas RC-Core3 was slightly increased until the middle stage and slowly decreased thereafter. And gradual degradation of trimeric LCHII progressed after the late stage of senescence. Exogenous application of NAA and GA$_{3}$ had little or no effect in protecting disassembly of chlorophyll-protein complexes during leaf senescence compared to control. However exogenous BA application strongly leaves. In the simultaneous treatment of plant hormones and light, BA application under illumination of light was most effective in the stability of chlorophyll-protein complexes, particularly PSI, LHCII, RC-Core2, RC-Core3 and SC-1. these results suggest, therefore, that simultaneous application of BA and light induced synergistic effect on the stability off chlorophyll-protein complexes during leaf senescence.

Electrical Fire Disaster Prevention Device of Double Protection using a High Precision Current Sensor in Low Voltage Distribution System (고정밀 전류센서를 이용한 저압배전계통 이중 보호용 전기화재 방재장치)

  • Kwak, Dong-Kurl;Jung, Do-Young
    • Fire Science and Engineering
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    • v.23 no.3
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    • pp.40-47
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    • 2009
  • Nowadays the diversity and large-capacity of electric appliances are strong effect on electrical fires augment in an alarming way. But, as the inactive response characteristics of the existing RCD (Residual Current protective Device) used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper is confirmed the unreliability of the existing RCD by electrical fault simulator and is proposed a Electrical Fire Disaster Prevention Device (EFDPD) by using a high precision current sensor (namely, reed switch) for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The sensitive reed switch in the proposed EFDPD exactly detects the increased magnetic flux with the overload or the short current caused by a number of electrical faults, and the following, the EFDPD has double protection function which operates self circuit breaker or rapidly cuts off the existing RCD. The proposed EFDPD is confirmed the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker through various operation performance analysis. The proposed EFDPD can also prevent electrical disaster, like as electrical fires, which resulted from the malfunction and inactive response characteristics of the existing RCD.

Design and Development of Intelligent Cattle Shed for the Prevention of Livestock Waste (가축 폐사 방지를 위한 지능형 축사의 설계 및 개발)

  • Jang, Junewoo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.32-35
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    • 2019
  • One of the major problems with the livestock industry is that in the summer, livestock will die from heat waves or infectious diseases. Under these circumstances, what livestock need is a proper indoor temperature and a regular sterilization system. Therefore, in this study, we developed a system that automatically controls the power of the fan according to the temperature inside the shaft, and a function that provides feed and sterilization on a regular basis, so that we could manage the toast efficiently. It also proposed the ability to automatically control the power of the fan, to display the temperature inside the shaft to mobile applications, and to provide food and sterilization. First, the function of controlling the power of the fan automatically turns the fan on when the temperature inside the shaft rises above a certain level. Conversely, if the temperature inside the shaft falls below a certain level, turn off the fan. Second, the function of the mobile application is to check the temperature inside the shaft. The third feeding function is periodically fed using a servo motor, and the feeding provided is delivered to livestock through a conveyor belt. Finally, the sterilization function is a function to sterilize livestock periodically using DC motor pump. The intelligent congratulatory functions proposed in this study may contribute to the health of livestock.

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Numerical Simulation on Control of Tsunami by Resonator (II) (for Samcheok port) (공진장치에 의한 지진해일파의 제어에 관한 수치시뮬레이션(II) (삼척항에 대해))

  • Lee, Kwang-Ho;Jeon, Jong-Hyeok;Kim, Do-Sam;Lee, Yun-Du
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.6
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    • pp.496-505
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    • 2020
  • In the previous research, the effectiveness of resonator was confirmed through the numerical analysis on two cases with the use of existing resonator at the Mukho and Imwon ports located in the eastern coast of South Korea by discussing the reduction rates of 1983 Central East Sea tsunami, and 1993 Hokkaido Southwest off tsunami, respectively. In this study, the reduction rates of tsunami height with three different resonators, Type I, II-1, and II-2, at the Samcheok port were examined respectively through the numerical analysis using COMCOT model under the same condition as the previous study. It was discussed the spatial distribution of maximum height of tsunami, change of water level, and effectiveness of resonator with the presence of new types of resonator, and change of their sizes. As a result, the effectiveness of resonator was verified through the application of new types of resonator reducing about maximum 40% of tsunami height. In order to design the optimal resonator for the variety of site condition, it is necessary to research about the various cases applying different shape, arrangement, and size of resonator as further study.

The Study of the Correlation between Media Art Creative City and Local festival - with Lyon, Sapporo, Linz as the central figure - (미디어아트 창의도시와 지역축제의 연관성 연구 - 리옹, 삿포로, 린츠를 중심으로 -)

  • Jeong, Hye Young;Kim, Kyoung Soo
    • Korea Science and Art Forum
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    • v.24
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    • pp.399-409
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    • 2016
  • This study's purpose is to research the correlation between property and the major festivals with media art of exemplary 3 cities among 8 Unesco Media Art Creative Cities. As a result, it is drawn a conclusion that the below strategies are necessary to achieve success for Unesco Media Art Creative City. First, from the Creative City's point of view, on the basis of the maximization of various merits such as history, natural surroundings, and human resources of the city, it is necessary to reconcile a vision of the city and an identity of Media Art Creative City, and to seek for continuous growth of the city by consistency and durability of control tower within the local government. Second, from the local festival's point of view, it is necessary to provide a differentiated service in the existing media art festivals, to attract the fusion of media art and festivals, and the diversification and the popularization of media art programs. And, it needs to lead to involvement of young people with the fusion of on-line and off-line festivals, the fusion of analogue and digital festivals. In the conclusion, for the successful constructing of Media Art Creative City, it is necessary to maximize the merits of the city's own, to enhance the image for Media Art Creative City with the correlation between the merits and media art, and to differentiate the city's own various festivals, ant the same time, to converge them with media art technology. With these strategies, the local festival can make a new leap for global festival when it constitutes a whole with Media Art Creative City.