Fundamental Study for Ocean Wave Energy Converter Using a Rack-Pinion Gear Based One-way Mechanism

이준경(Lee, Junkyoung),조성일(Cho, Sungil),이세한(Lee, Sehan),이상천(Lee, Sangchun),노현철(No, Hyunchul) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05

Sustainable energy generation is becoming extremely imperative due to the expected limitations in current energy resources and to reduce pollution. Especially, because of its considerable energy potential, ocean wave energy has been investigated with regard to power generation. To develop large high power wave generator system, it is important to make a small scale proto type and to test that. Thus the objective of this research is to examine the characteristics of a mechanically excited generator system having small power capacity experimentally. The water reservoir (4 m length, 1.5 m width and 1.8 m depth) having a wave maker to make arbitrary height and period of the water wave was made. The proto type consists of three main parts; a buoy, rack-pinion base one-way mechanism, and a wave generator(Fig.1). The water wave is going up and down and the hexahedron buoy is following the wave. The rack gear attached to the buoy is also going up and down to roll the pinion connected to an electric generator then it produces electricity. The experiments were performed with several conditions of water waves, and the power outputs over 30 W could be measured for some conditions. In future works, to achieve higher performance for the proto type, the effects of primary parameters (buoy shape and mass, etc.) on the system efficiency will be identified.

An End-to-End Virtual Path Construction System for Stable Live Video Streaming over Heterogeneous Wireless Networks

Sangchun Han,Hyunchul Joo,Dongju Lee,Hwangjun Song IEEE 2011 IEEE journal on selected areas in communications Vol.29 No.5

<P>In this paper, we propose an effective end-to-end virtual path construction system, which exploits path diversity over heterogeneous wireless networks. The goal of the proposed system is to provide a high quality live video streaming service over heterogeneous wireless networks. First, we propose a packetization-aware fountain code to integrate multiple physical paths efficiently and increase the fountain decoding probability over wireless packet switching networks. Second, we present a simple but effective physical path selection algorithm to maximize the effective video encoding rate while satisfying delay and fountain decoding failure rate constraints. The proposed system is fully implemented in software and examined over real WLAN and HSDPA networks.</P>

Emotional Communication System for Hard of Hearing

Sanghoon Lee,Minwoo Choi,Hyejin Koo,Sangchun Park 한국차세대컴퓨팅학회 2022 한국차세대컴퓨팅학회 학술대회 Vol.2022 No.10

There needs an opportunity for hard of hearing to express their emotions and to have a natural conversation. Communicating through text or sign languages is not easy to fully express emotions, especially in situations where conversation partners are invisible, such as on a phone call. In this paper, we design a emotional conversation system for hard of hearing based on text emotion recognition (TER), emotional speech synthesis (ESS), and speech-to-text (STT). This system allows them to convey both their opinions and feelings accurately.

Spatio-Temporal Beam Signature 생성 및 이를 활용하는 빔 관리 방안

박상천(Sangchun Park),이성빈(Sungbeen Lee),유준혁(Junhyuk Yoo),최민우(Minwoo Choi),성원진(Wonjin Sung) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.8

맥루한의 모자이크 사고방식과 사례연구 : T_Visionarium' 과 'Cultural Analytics' 분석을 중심으로

이은아(Lee Eunah),박상천(Park Sangchun) 한국디지털디자인학회 2011 디지털디자인학연구 Vol.11 No.2

디지털 시대로 들어서면서 정보를 대규모로 아카이빙하는 작업들이 진행 중이다. 이 시점에서 인류의 기억을 대체하는 방대한 양의 디지털 데이터들을 어떻게 다루어야 하는가라는 질문이 제기되고 있다. 그래서 본 연구에서는 새로운 디지털환경의 도래를 미디어 관점에서 예리하게 내다봤던 미디어학자 맥루한의 이론을 살펴보았다. 그의 이론 중에서 영화와 사진매체 발명으로 나타난 이미지 몽타주의 계보를 잇는 모자이크 사고방식을 살펴보고 새로운 디지털 성향으로 나타나는 융합에 이르기까지의 전반적인 유사한 개념들도 함께 고찰하였다. 뉴미디어아트의 사례로 먼저 시네마 환경 안에서 인간의 감정 감각을 지표로 아카이빙한 영상데이터들을 관객이 직접 참여해서 재조합하도록 유도하는 실험을 행하는 미디어아티스트 제프리 쇼의 <T_Visionarium>과 데이터처리 소프트웨어의 중요성을 고찰하는 미디어학자 레프 마노비치의 문화 데이터 시각화분석에 대한 연구인 <Cultural Analytics>를 살펴보았다. 그 결과 디지털 시대는 상호 유기적이면서도 불연속적인 조각의 정보들을 횡단하며 그 사이에 새롭게 나타나는 관계를 규명하는 사고능력을 요구하며 이는 인간의 다양성의 인정과 원활한 상호소통에 대한 열망에서 비롯되고 있음을 알게 되었다. 무엇보다도 조각을 연결하고 전체를 분석하는 사고력 안에서 과연 이 시대의 예술의 역할은 무엇인가에 대한 연구는 앞으로도 계속되어야 할 것이다. Entering into the digital age a huge volume of information is being archieved. Nowadays it is true that digital data replaces human memory. The question is how the vast amount of digital data should be dealt with. Thus this study examined the theory of media scholar McLuhan who foresaw the coming of new digital environment through his penetrating insight into the trends of media. In particular the mosaic thinking method was focused on inherits the lineage of image montage which emerged with the invention of movie and photography and discussed similar concepts related to new digital trends including convergence. In addition this study reviewed cases of new media art including media artist Jeffrey Shaw's <T_Visionarium> which experiments on the recombination of image data of human emotions and sensations through audience's direct participation. And also media scholar Lev Manovich's <Cultural Analytics> which is analysis of visualization of cultural data and information collection based on the importance of data processing software was reviewed. From the results of these studies what has found is that the digital age demands thinking abilities to transverse interconnected and discontinuous pieces of information and discover newly observed relations in them. This issue derived from identification for diversity of human nature and desire for better communication. Thus among other things research should be continued on what roles arts play in thinking abilities to connect pieces of information and analyze the whole.

Determinants and Dimensions of Supply Chain Evolution Path

JongDae Kim,SangChun Lee 한국무역연구원 2016 貿易 硏究 Vol.12 No.1

Vertical integration, as well as outsourcing, are typical make or buy decisions and have beengiven attention in the academic area and among practitioners. Many previous studies havebeen done on the determinants of the span of process of a firm and the related choice ofappropriate governance structure. In turn, those decisions affect an appropriate structure ofsupply chain which continually evolves with environmental changes. In this study, we proposean evolution map of supply chains and groups of accelerators and decelerators whichaccelerate or decelerate the evolution of supply chains.In creating a supply chain evolution map, we define three dimensions of the evolution,namely, span of process, supplier base structure and inter-organizational relationship. Followingthese dimensions, we propose three stages for each dimension: full spectrum, core andoutsourcing and Micro-some for the first dimension, span of process. One-to-one, N-to-one andNo-to-N for the second dimension, supplier base structure.

궤환 신호의 통계적 학습을 통한 자율적 빔포밍을 수행하는 무선 유닛 설계 방안

최민우(Minwoo Choi),박상천(Sangchun Park),이성빈(Sunbeen Lee),성원진(Wonjin Sung) 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.6

제한된 궤환량을 갖는 채널 상태 정보를 활용하여 효율적인 빔포밍을 수행하는 방안은 거대규모 다중 입출력 송수신 전송을 위해 중요한 설계 요소이다. 5G NR 을 비롯한 3GPP 표준에서 채택되어 사용되는 이산 푸리에 변환 기반 코드벡터를 사용하는 빔포밍은 서비스 영역의 지리적 특성과 사용자 분포에 무관한 고정된 위치로의 빔 형성을 수행함으로 인해 환경 및 이동성 적응에 제약을 갖는다. 본 논문에서는 사용자의 궤환 신호를 통계적으로 활용하는 심층 학습을 적용하여 무선 유닛에서 자율적으로 코드벡터를 변형하여 빔포밍을 수행하는 방안을 제안하고 적용 사례를 소개한다.

응급실에서 시행한 소변 독성 검사의 유용성: 마약을 중심으로

이세규 ( Se Kyu Lee ),최상천 ( Sangchun Choi ) 대한임상독성학회 2021 대한임상독성학회지 Vol.19 No.1

Purpose: In Korea, it is predicted that the proportion of drug abusers among patients visiting the emergency room will soon increase. Several emergency medical institutions in Korea are conducting field urine screening tests for poisoning. In this study, we investigated the characteristics and usefulness of urine toxicology screening tests. Methods: The medical records of patients with positive results for tetrahydrocannabinol and methamphetamine from urine toxicology screening tests at a tertiary university hospital from August 2016 to August 2019 were reviewed retrospectively. The subjects were classified into positive and false-positive groups, and their clinical characteristics were compared and analyzed. Results: Of the 2,026 patients surveyed, 823 patients (40.6%) tested positive for one or more drugs. Among them, 12 cases (0.6%) were positive for methamphetamine and 40 cases (2.0%) were positive for tetrahydrocannabinol. The positive and the false-positive rates for methamphetamine were 66.7% and 33.3%, respectively. The positive and the false-positive rates for tetrahydrocannabinol were 2.5% and 97.5%, respectively. Conclusion: Methamphetamine showed a relatively low false-positive rate in our study. Therefore, this test seemed to assist in diagnosing methamphetamine poisoning when considered together with the present illness and physical examination results. On the other hand, the high false-positive rate for tetrahydrocannabinol tests indicates that this test was unlikely to assist in diagnosing tetrahydrocannabinol poisoning. However, considering the growing trend of illegal drug abusers in Korea, it may still be useful as a diagnostic tool for identifying drug users.

급성 아세트아미노펜 중독에서 N-acetylcysteine 투여 결정 관련 인자

이정화 ( Jeong Hwa Lee ),최상천 ( Sangchun Choi ),윤상규 ( Sang Kyu Yoon ),신규철 ( Kyu Cheol Shin ) 대한임상독성학회 2020 대한임상독성학회지 Vol.18 No.2

Purpose: In acute acetaminophen poisoning, the administration of N-acetylcysteine (NAC) can effectively treat the main complications, such as kidney injury and liver failure. In the current situation, measurements of the acetaminophen concentration are not checked in the usual medical facilities. Therefore, this study examined the factors of determining the administration of NAC in addition to the stated amount of intake. Methods: The medical records of patients who visited Ajou University Hospital emergency center with acetaminophen poisoning from January 2015 to December 2019 were reviewed retrospectively. One hundred and seventy-nine patients were initially included. Among these patients, 82 patients were finally selected according to the inclusion criteria in the study. The inclusion criteria were as follows: patients who were 15 years of age or older; those whose ingested dose, ingested time, and body weight were clearly identified; and patients whose acetaminophen sampling time was within 24 hours. Patients were divided into two groups: NAC administered vs. non-NAC administered. The following variables were compared in these two groups: ingested dose, ingested dose per body weight, hospital arrival time after ingestion, suicide attempt history, psychiatric disease history, classification of toxic/non-toxic groups, duration of hospitalization, and laboratory results. Results: Univariate analysis revealed the ingested dose per body weight, hospital arrival time after ingestion, suicide attempt history, and psychiatric disease history to be the determining factors in administering NAC. Logistic regression analysis confirmed that the ingested dose per body weight was the only significant factor leading to an NAC treatment decision. (Odds ratio=1.039, 95% Confidential interval=1.009-1.070, p=0.009) Conclusion: The ingested dose per body weight was the only determining factor for administering NAC in patients with acute acetaminophen poisoning. On the other hand, additional criteria or indicators for the NAC administration decision will be necessary considering the inaccuracy of the ingested dose per body weight and the efficiency of NAC administration.

A Mentorship Model based on KIGES' Mentorship program

Hyun sook Sung(성현숙),SangChun Lee(이상천),JungYun Heo(허정윤),JeongSoo Woo(우정수) 한국영재학회 2004 영재교육연구 Vol.14 No.4

심화교육의 한 형태인 사사교육은 21세기를 주도할 과학영재들에게 적합한 교 육방법으로 알려져 오고 있다. 사사교육은 과학영재들에게 멘터와의 긴밀한 관 계 및 연구를 통해 자신의 능력 및 과학자로서의 태도를 기르는 데 도움을 주고 있다. 경남대학교 과학영재교육원 (KIGES)은 지난 5년간 사사교육 프로그램을 운영해 오고 있다. KIGES의 경험을 포함하여 사사교육이 과학영재에게 제공하 는 이점들을 토대로 사사교육 모형을 제안하였다. 이 사사교육 모형은 향후 사 사교육 참여자들에게 사사교육의 과정을 용이하게 할 뿐만 아니라 사사교육의 효과를 증진시키는 데 도움이 될 것으로 사료된다. Mentorship as an enrichment program as well as a promising educational method in the 21st century for the gifted students in science provides young scientists with opportunities to develop their abilities and attitudes regarding research. Kyungnam Institute of Gifted Education in Science (KIGES) has run mentorship program for five years. Many advantages of mentorship program for the science gifted students are reviewed including those of KIGES. A mentorship model for future student research programs is proposed as a way to facilitate the process of mentorship. Key words: Mentorship model, enrichment program, constructivism