• Title/Summary/Keyword: 고정원 강화

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Optimal deployment of sonobuoy for unmanned aerial vehicles using reinforcement learning considering the target movement (표적의 이동을 고려한 강화학습 기반 무인항공기의 소노부이 최적 배치)

  • Geunyoung Bae;Juhwan Kang;Jungpyo Hong
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.2
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    • pp.214-224
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    • 2024
  • Sonobuoys are disposable devices that utilize sound waves for information gathering, detecting engine noises, and capturing various acoustic characteristics. They play a crucial role in accurately detecting underwater targets, making them effective detection systems in anti-submarine warfare. Existing sonobuoy deployment methods in multistatic systems often rely on fixed patterns or heuristic-based rules, lacking efficiency in terms of the number of sonobuoys deployed and operational time due to the unpredictable mobility of the underwater targets. Thus, this paper proposes an optimal sonobuoy placement strategy for Unmanned Aerial Vehicles (UAVs) to overcome the limitations of conventional sonobuoy deployment methods. The proposed approach utilizes reinforcement learning in a simulation-based experimental environment that considers the movements of the underwater targets. The Unity ML-Agents framework is employed, and the Proximal Policy Optimization (PPO) algorithm is utilized for UAV learning in a virtual operational environment with real-time interactions. The reward function is designed to consider the number of sonobuoys deployed and the cost associated with sound sources and receivers, enabling effective learning. The proposed reinforcement learning-based deployment strategy compared to the conventional sonobuoy deployment methods in the same experimental environment demonstrates superior performance in terms of detection success rate, deployed sonobuoy count, and operational time.

Verifying the Causal Relationship of the Dancer's Ability to Trust and Objectives and Confidence (무용수의 능력믿음과 목표 및 자신감의 인과 관계 검증)

  • Lee, Dong-Sook
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.2
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    • pp.51-62
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    • 2020
  • The study was conducted to verify the causality of the ability of high school and college dance majors to influence the successful goal orientation and how the change in goal affects the sense of dance performance self-confidence. In this regard, 172 dance majors were collected to collect data on their belief in dance ability, the direction of mastery goal of approach and avoidance, and the measure of confidence in dance performance, and the results of their studies were derived through correlation and structural equation analysis and path analysis. The analysis results showed reasonable factor structure and reliability based on the preceding study of feasibility analysis results between variables. Thus, the structural equation for the study variables confirmed that the theoretical hypothesis was suitable, and the path of each variable was verified through the path analysis. The analysis showed that the increased belief that ability can be improved by effort has been found to improve the effort and consequently the confidence in dancing. Also, the fixed belief that ability is not changing in a fixed sense has been found to affect the avoidance goal and reduce confidence. It can be interpreted that the more one believes that one can change one's ability by effort, the more one strengthens one's actions to achieve one's goal, thereby improving one's dance confidence. Therefore, it is deemed necessary for subsequent studies to explore whether the paths of these models differ by their major or dance careers, and to apply variables that can measure the success or failure of actual performances to enhance the explanatory power of these research variables.

The pattern of movement and stress distribution during retraction of maxillary incisors using a 3-D finite element method (상악 전치부 후방 견인 시 이동 양상과 응력 분포에 관한 삼차원 유한요소법적 연구)

  • Chung, Ae-Jin;Kim, Un-Su;Lee, Soo-Haeng;Kang, Seong-Soo;Choi, Hee-In;Jo, Jin-Hyung;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.37 no.2 s.121
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    • pp.98-113
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    • 2007
  • Objective: The purpose of this study was to evaluate the displacement pattern and the stress distribution shown on a finite element model 3-D visualization of a dry human skull using CT during the retraction of upper anterior teeth. Methods: Experimental groups were differentiated into 8 groups according to corticotomy, anchorage (buccal: mini implant between the maxillary second premolar and first molar and second premolar reinforced with a mini Implant, palatal: mini implant between the maxillary first molar and second molar and mini implant on the midpalatal suture) and force application point (use of a power arm or not). Results: In cases where anterior teeth were retracted by a conventional T-loop arch wire, the anterior teeth tipped more postero-inferiorly and the posterior teeth moved slightly in a mesial direction. In cases where anterior teeth were retracted with corticotomy, the stress at the anterior bone segment was distributed widely and showed a smaller degree of tipping movement of the anterior teeth, but with a greater amount of displacement. In cases where anterior teeth were retracted from the buccal side with force applied to the mini implant placed between the maxillary second premolar and the first molar to the canine power arm, it showed that a smaller degree of tipping movement was generated than when force was applied to the second premolar reinforced with a mini implant from the canine bracket. In cases where anterior teeth were retracted from the palatal side with force applied to the mini implant on the midpalatal suture, it resulted in a greater degree of tipping movement than when force was applied to the mini implant between the maxillary first and second molars. Conclusion: The results of this study verifies the effects of corticotomies and the effects of controlling orthodontic force vectors during tooth movement.

THE EFFECT OF LIGATION METHOD ON THE FRICTIONAL FORGE BETWEEN ORTHODONTIC BRACKET AND ARCHWIRE (결찰양식이 교정용 브라켓과 교정선 사이의 마찰력에 미치는 영향)

  • Shin, Hyun-Jeong;Kwon, Oh-Won;Kim, Kyo-Han
    • The korean journal of orthodontics
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    • v.28 no.5 s.70
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    • pp.813-823
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    • 1998
  • The frictional force has been considered as an harmful factor in an active unit where tooth movement occurs, but as an advantageous factor in anchor unit that resist tooth movement. That is, efficient tooth movement is planned by using ligation methods that have low levels of bracket-wire frictional force and the anchorage control can be achieved by using ligation methods that have high levels of bracket-wire frictional force that result in binding of the bracket accompanied by little or no tooth movement. The purpose of this study was to evaluate the frictional force generated between bracket and wire in accordance with the methods of ligation, the material of ligation and the passage of time under artificial saliva. Tested were 0.017x0.022 inch stainless steel wires in standard edgewise twin brackets for upper central incisors in a 0.018-inch slot. The wires were ligated into the brackets with elastomeric modules and stainless steel ligatures. Whole tie, half tie, twisting tie and double overlay tie were done with elastomeric modules. With 0.009-inch stainless steel ligature whole tie and half tie were done by needle holder and whole tie by ligature tying plier. With 0.012-inch stainless steel ligature whole ties were done by needle holder. Whole tie groups of elastomeric module were kept in artificial saliva bath at $37^{\circ}C$ for 28 days. The frictional force was recorded by means of an Instron universial testing instrument (4202 INSTRON, Instron Co., U.S.A.) at initial, 7, 14, 21, and 28 days. The results for ligated samples in a simulated oral environment revealed the fellowing : ${\cdot}$In elastomeric module whole tie, 28 days group was significantly greater mean static frictional force than any other group but there were no significant differences among any other group (p>0.05). ${\cdot}$Elastomeric module twisting ties were significantly greater mean static frictional forces than any other ligation method but there were no significant differences between twisting tie and double overlay tie (p>0.05). Twisting tie, double overlay tie, whole tie, half tie showed differences in decreasing order. ${\cdot}$Stainless steel half tie produced lower mean static frictional force than whole tie, ligation by ligature tying plier produced greater mean static frictional force than by needle holder and ligation with 0.012-inch stainless steel ligature produced greater mean static frictional force than with 0.009-inch stainless steel ligature (p<0.05). ${\cdot}$There were no significant differences between the mean static frictional forces of elastomeric whole tie and stainless steel whole tie (p>0.05).

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Characteristics of Total Organic Carbon and Chemical Oxygen Demand in the Coastal Waters of Korea (한국 연안수에서 총유기탄소 및 화학적 산소요구량 분포 특성)

  • 손주원;박용철;이효진
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.3
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    • pp.317-326
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    • 2003
  • In order to improve our knowledge of the characteristics of organic compounds in coastal waters, water samples were collected from the Incheon coastal region, the Hyungsan River in Youngil Bay and the Busan coastal region. Also, mooring was carried out near the Kanghwa Island and Seo Island. In this study, the relationship between the total organic carbon (TOC) and salinity, chemical oxygen demand (COD) and salinity were evaluated and determined. Riverine end-member of TOC into the Korean coastal area and its COD estimated from these relationships were 5.32 mg C/l and 8.87 mg O$_2$/l, respectively. The oxidation efficiency of COD to TOC estimated using the high-temperature catalytic oxidation method was about 47%. The linear relationship between TOC and COD was derived as COD (mg O$_2$/l)=0.61${\times}$TOC (mg C/l) -0.03, (R$^2$=0.66). Therefore, it is possible to estimate total organic carbon using this equation from previously reported chemical oxygen demand.

Chlorella as a Functional Biomaterial (기능성 생물 소재로서의 클로렐라)

  • 채희정;강민숙;심상준
    • KSBB Journal
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    • v.19 no.1
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    • pp.1-11
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    • 2004
  • Chlorella contains a rich source of biochemical products with applications in the feed, food, nutritional, cosmetic, pharmaceutical and even fuels industries. Chlorella is one of unicellular green algae and is mostly grown in fresh water such as pond and lake. It grows in a manner of nonsexual reproduction so that it multiplies 4~16 times overnight. Large-scale culture is conducted by open pond culture or pure culture using fermenter. Chlorella has various efficacies such as heavy metal removal, degradation of toxic materials, control of arteriosclerosis, immunoprotective effects, anticancer activity and growth-stimulating activity of intestinal bacteria. Chlorella can be used as a taste enhancer and foodstuff, as it has a plenty of essential amino acids, polyunsaturated fatty acids, sterols and chlorella growth factor (CGF). Chlorella is a potential organism which can be utilized for CO$_2$ removal and H$_2$ Production in environmental area and energy Production.

A Study on the Change and Improvement of Smart Grid Policy after the Great East Japan Earthquake (동일본대지진 이후 일본 스마트그리드 정책의 변천과 개선방안 연구)

  • Lee, Jum-Soon
    • Journal of Digital Convergence
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    • v.15 no.7
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    • pp.41-53
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    • 2017
  • This study focuses on the current state of Smart Grid policy in Japan and its problems while the interest in Smart Grid has been increasing since the March 2011 earthquake in East Japan. As a result of the analysis, Japan introduced the fixed price buying system of new and renewable energy in response to the power supply and demand problem caused by the 2011 earthquake in East Japan, and established a decentralized green electricity trading market in which electricity generated from new and renewable energy is traded Smart Grid-related projects were implemented as a solution to solve energy crisis and environmental problems at the same time. As a result, we achieved visible results such as suppressing peak power, reducing CO2 emissions, and securing stable supply and demand of energy using renewable energy sources. On the other hand, the improvement of current Smart Grid policy operation in Japan and the introduction of stabilization system of power system, promotion of international standards of domestic technology related to smart grid, and support for strengthening security of smart grid.

Developing Framework for Flood Loss Estimation Model of General Building Based on High Resolution Inventory (고해상도 인벤토리 기반 일반건물 홍수손실 예측 모델)

  • Kim, Gil Ho;Kim, Gyung Hoon;Kim, Kyung Tak;Oh, Eun Ho
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.135-135
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    • 2015
  • 2004년 개발된 다차원홍수피해산정법(MD-FDA)은 홍수에 따른 경제적 피해를 추정하기 위한 기법으로서 그 동안 하천설계기준, 댐설계기준, KDI 예비타당성조사 지침 등에 반영되어 실무에서 활발히 사용 중이다. 그러나 그 동안 많은 연구에서 MD-FDA의 인벤토리 체계, 가용자료의 정밀성, 손상함수, 손실유형 범위와 관련한 개선이 요구되었으며, 최근에는 재난위기 관리 능력강화를 위한 "한국형 재난피해 예측 시스템" 개발의 필요성이 제기되면서 현재 다양한 분야의 전문가들이 재난손실과 관련한 많은 연구를 진행 중이다. 이에 본 연구는 국외 주요 홍수손실 예측 모델과 현재 국가차원에서 서비스되는 상세자료를 검토하여 일반건물(general building)의 홍수손실 평가 체계를 제시하고, 이와 연관된 세부요소 기술을 정립하였다. 우선, 지역 내 건물현황 및 특성정보가 참조가능한 자료를 바탕으로 일반건물의 유형을 분류하였고, 이밖에 건물손실 평가에서 주요 참고자료로 활용되는 인구, 종사자수 등의 사회 경제적 정보를 연계한 인벤토리 DB 구조를 설계하였다. 이로부터 구축되는 인벤토리 DB는 위치정보를 포함하는 공간자료이며, 손상(damage)과 손실(loss)을 평가하기 위한 건물특성 정보를 포함한다. 한편, 본 연구에서의 건물손실은 자산의 총가치를 기준으로 한 상대적 손상률(%)을 설명하는 손상함수를 기반으로 하기 때문에 감가상각을 고려한 건물의 완전대체비용(건물자산가치)가 정의되어야 한다. 이를 위해 본 연구는 최근 한국감정원에서 발간한 "건물신축단가표"와 "유형고정자산 내용연수표"를 바탕으로 손실평가에 필요한 요소기술을 정립하였다. 제시한 일련의 과정은 동두천시 신천 범람사례를 대상으로 적용하였고, 그 결과를 기존의 MD-FDA 결과와 비교하였다.

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Meanings of Family Reproduced by the Real Entertainment Program (리얼 예능 프로그램 <삼시세끼>가 재현한 가족에 관한 연구)

  • Jun, Mikyung;Lee, Jungwon;Kim, Jiwook
    • The Journal of the Korea Contents Association
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    • v.22 no.5
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    • pp.553-564
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    • 2022
  • The purpose of this study is to examine the family reproduced by fishing village episode 1. (삼시세끼, three meals a day), which attempted a new type of entertainment termed an experiential real entertainment documentary, was produced in a total of nine episodes from October 2014 to March 2015. This study analyzed fishing village episode 1, which was aired in 2015 and obtained the highest ratings, using narrative analysis. The development of was consistently structured in the order of 'wake up - free time - breakfast - lunch - dinner - rest - sleep'. The character construction of the characters was created through the arrangement of a main space and a main role for each of the characters. Also, the characters were in relationships through which they became the background of each other. Therefore, in the family reproduced by , a mother without a father and a father without a mother are impossible. Despite that all the cast members were male, the subtitles constantly gave them the roles of 'housewife/wife/mother', 'father/husband/dad', and 'son', while actively blocking the image of a homosexual family. The family created as such was a family with children, a family with both mother and father, a heterosexual family, and a nuclear family. As a result, reproduced the typical modern family, normal family, and standard family.

The effect of self-objectification through the user's postural habit analysis on the practice of correct posture: App service proposal through EMG sensors and wearable devices (사용자의 자세 습관 분석을 통한 자기 객관화가 바른 자세 실천에 미치는 영향: 근전도센서 및 웨어러블 기기를 통한 앱 서비스 제안)

  • Ye-eun Ko;Ye-jun Kim;Seon Kim;Jae-sun Yi
    • Industry Promotion Research
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    • v.8 no.1
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    • pp.11-22
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    • 2023
  • This study proposes service content that helps people stay in the right posture in their daily lives to manage the pain of musculoskeletal diseases. Resistance factors and induction factors were analyzed through a survey of 143 people and Ethnography. Based on this, we propose an app service that helps practice the right posture by using EMG sensors and wearable devices. This study is meaningful in alleviating musculoskeletal pain and further improving the quality of life by helping to practice and maintain the right posture with service content based on self-objectification through user posture habit analysis.