해양공간 정책시뮬레이션 기술 개발 - 현황 및 도전과제

조성진(Sung-Jin Cho),강전영(Jeon-Young Kang),박재영(Jaeyoung Park),최희정(Hee-Jung Choi),남정호(Jungho Nam) 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.5

“실제로 존재하지 않는 대상을 존재하는 것처럼 만들어 놓은 인공물"을 뜻하는 라틴어 '시뮬라크르(simulacre)'에서 파생된 시뮬레이션(simulation)은, 복잡한 문제를 해석하기 위해서 실제와 비슷한 상태(시스템)를 모델로서 구현하고, 반복 연산을 통해 최적해를 찾는 과정을 뜻한다(Baudrillard, 1994). 전통적인 분석적 방법론(analytical method)은 계수 추정을 통해서 특정 시점의 두 변수, 즉 독립변수와 종속변수의 상관성을 규명하는데 반해, 시뮬레이션 방법론(simulation method)은 현상의 재현을 통해서 과정을 파악하는데 목적을 둔다. 이러한 특징으로 말미암아 시뮬레이션 기법은 문제의 최적해보다 현상의 규명에 더 적합한 방법론이다. 자연계 (nature system)의 문제(가령, 산사태의 발생원인)는 요인들 간 단순하고 명확한 관계에 의해서 정의되지만, 인간계(human system)의 문제(가령, 부동산 가격상승의 원인)는 비교적 복잡하고 불명확한 관계에 의해서 규정된다. 따라서 주로 인간관계에서 비롯되는 사회 문제를 해결하기 위한 수단으로써 정책은 시뮬레이션 기술을 적용하기에 적합한 대상이다. 일반적으로 정책은 결과 못지않게 과정도 중요하며(당위성), 현재·미래 문제를 포괄하고, 긍정적·부정적 효과(양면성)를 함께 고려하므로, 시뮬레이션은 이러한 요건에 잘 부합하는 기술이다. 최근 노인복지(백의현, 2019), 미세먼지(심창섭, 2019), 주택시장(최명섭&변세일, 2016), 인구센서스(배장현 외, 2016) 등 다양한 정책분야에서 시뮬레이션 기술이 활용되고 있다. 2019년에 재정된 “해양공간계획 및 관리에 관한 법률”에 근거한 해양공간기본·관리계획, 해양용도구역, 해양공간적합성협의 등은 해양자원의 효율적 이용과 해양공간의 갈등 및 상충을 해소하기 위한 해양수산 분야의 新정책수단이다. 최근 해양관광, 골재채취, 해상풍력, 해상경계분쟁 등 사회적 이용 및 갈등이 심화되면서 실효성 있는 해양공간정책의 요구가 높아지고 있는 실정으로, 해양정책을 정확하게 평가하고 지원할 수 있는 과학적 도구가 절실하다. 해양공간은 환경·생태계, 지역사회, 수산업, 관광업, 에너지개발 등 복잡한 이해관계가 얽혀 있으며, 정책평가 시 이러한 관계를 명확하게 정의하고 고려해야 한다. 본 연구는 해양공간정책 지원도구로써 해양정책시뮬레이터(Ocean Policy Simulator, OPSim)를 제안하며, 대표적인 복잡계 연구방법론으로서 거시적 현상을 미시적 행위자의 상호작용으로 설명하기 위해 제안된 행위자기반모형(Agent-Based Model, ABM)을 적용하고자 한다. ABM은 정책 대상 및 환경의 동적 변화와 더불어, 자연·인문 환경과의 상호작용(상충 또는 시너지)이 활발한 해양 분야에 적합한 방법이지만, 동시에 시뮬레이션 결과에 대한 검증의 어려움과 모델 인자의 초기값에 대한 의존성 등 한계점을 내포하고 있다. 따라서 ABM을 적용한 OPSim 개발 과정에서 빅 데이터를 활용한 AI기술, 자가진화 시뮬레이션 기법(self-evolving simulation), 시스템다이나믹스(system dynamics) 등을 활용하여 한계점을 보완할 수 있다(Scheutz et al., 2016; Kang et al., 2016; Bae et al., 2018; Kavak et al., 2018). Simulation derived from the Latin word "simulacre" for "artificial objects that actually do not exist" means the process of modeling a realistic state (system) to interpret complex problems and finding an optimal solution through repeated operations (Baudrillard, 1994). While a traditional analytical method defines the correlation of two variables (i.e., independent variables and dependent variables) through coefficient estimation, a simulation method aims to identify the process through the reproduction of phenomena. Therefore, a simulation technique is a more suitable methodology for identifying phenomena rather than finding an optimal solution. The problem of the natural system (e.g. landslides) is defined by simple and clear relationships between factors, but that of the human system (e.g. real estate prices) is defined by relatively complex and unclear relationships. Therefore, a policy as a means of solving social problems, primarily derived from human relationships, is suitable for applying a simulation technique. Simulation is a technology that meets these requirements well, as a policy addresses the procedure as important as the result, solving current and future problems, and considering both positive and negative effects. Recently, simulation technology has been used in various policy areas such as welfare for senior citizens (Baek, 2019), fine dust (Shim, 2019), housing market (Choi&Byun, 2016), and population census (Bae et al, 2016). Marine space policies based on the Marine Space Planning and Management Act, which was enacted in 2019, such as marine spatial basic and management plans, marine use zones, and marine space suitability consultations are new political tools for efficient use of marine resources and management of conflicts. As social use and conflicts such as maritime tourism, aggregate collection, off-shore wind power, and maritime border disputes have intensified recently, calls for effective marine spatial policies are increasing, and scientific tools are urgently needed to accurately evaluate marine policies. Since marine space is intertwined with complex interests such as the environment, ecosystem, community, fisheries, tourism, and energy development, a marine spatial policy support tool should define and consider these relationships for policy evaluation. This paper proposes Ocean Policy Simulator (OPSim) as a support tool for marine spatial policy. Specifically, we aim to highlight the usefulness of an agent-based model (ABM) to explore human-nature interactions (i.e., conflict or synergy) and to provide policy implications. Using an ABM for such purposes often meet the issues in regard to verification and validation of the model’s structures and outcomes. However, AI technology using spatiotemporal bigdata, self-evolution simulation techniques, and system dynamics can help to tackle validation and verification procedures in the development process of OPSim using ABM (Scheutz et al., 2016; Kang et al., 2016; Bae et al., 2018; Kavak et al., 2018).

온톨로지 계층관계를 이용한 서비스 발견 알고리즘

최원종(Wonjong Choi),양재영(Jaeyoung Yang),최중민(Joongmin Choi),조현규(Hyeonkyu Cho),조현성(Hyeonsung Cho),김경일(Kyungll Kim) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.2Ⅰ

인터넷망의 지속적인 발달과 더불어 웹서비스가 차지하는 비중은 매우 커지고 있다. 이와 관련해 서비스 발견을 위한 다양한 노력들이 진행되었으며, 그 중에서도 DAML-S문서로 기술된 매치메이커에서 제시한 알고리즘은 서비스 발견자와 서비스 제공자사이의 서비스 발견에 대한 유사도 측정의 한 방법을 제시하고 있다. 하지만 온톨로지상의 관계표현에 있어 네 가지 규칙만을 적용하여 정밀한 유사도측정이 불가능하다는 단점이 있다. 따라서 본 논문에서는 기존의 알고리즘의 개선을 위해 두 가지 유사도 측정함수 1) 계층구조함수 2) 계층계수함수를 정의하고, 이에 기반한 새로운 서비스 발견 알고리즘을 제시하고자 한다.

A Current-Sourced LED Driver Compatible With Fluorescent Lamp Ballasts

Jaeyoung Choi,Hee-Seok Han,Kwyro Lee IEEE 2015 IEEE TRANSACTIONS ON POWER ELECTRONICS - Vol.30 No.8

<P>A light-emitting diode (LED) driver compatible with fluorescent lamp (FL) ballasts is presented for a lamp-only replacement without rewiring the existing lamp fixture. Ballasts have a common function to regulate the lamp current, despite widely different circuit topologies. In this paper, magnetic and electronic ballasts are modeled as nonideal current sources and a current-sourced boost converter, which is derived from the duality, is adopted for the power conversion from ballasts. A rectifier circuit with capacitor filaments is proposed to interface the converter with the four-wire output of the ballast. A digital controller emulates the high-voltage discharge of the FL and operates adaptively with various ballasts. A prototype 20-W LED driver for retrofitting T8 36-W FL is evaluated with both magnetic and electronic ballasts. In addition to wide compatibility, accurate regulation of the LED current within 0.6% error and high driver efficiency over 89.7% are obtained.</P>

Remediation of heavy metal using treatment agents for acid mine drainage

Jaeyoung Choi(최재영),Jung-Seok Yang(양중석),Ju Young Lee(이주영),Dongwook Kwon(권동욱) 한국지반환경공학회 2007 한국지반환경공학회 학술발표회논문집 Vol.2007 No.-

A Smart Service Robot Middleware on Ubiquitous Network Environments

Choi, Jongsun,Choi, Jaeyoung,Ko, Hoon,Bae, Kitae,An, Kyung Jin,Kim, Choong Sik,Choi, Jongmyung Informa UK (Taylor Francis) 2014 INTELLIGENT AUTOMATION AND SOFT COMPUTING Vol.20 No.1

Reduced Water Vapor Transmission Rate of Graphene Gas Barrier Films for Flexible Organic Field-Effect Transistors

Choi, Kyoungjun,Nam, Sooji,Lee, Youngbin,Lee, Mijin,Jang, Jaeyoung,Kim, Sang Jin,Jeong, Yong Jin,Kim, Hyeongkeun,Bae, Sukang,Yoo, Ji-Beom,Cho, Sung M.,Choi, Jae-Boong,Chung, Ho Kyoon,Ahn, Jong-Hyun,Pa American Chemical Society 2015 ACS NANO Vol.9 No.6

<P>Preventing reactive gas species such as oxygen or water is important to ensure the stability and durability of organic electronics. Although inorganic materials have been predominantly employed as the protective layers, their poor mechanical property has hindered the practical application to flexible electronics. The densely packed hexagonal lattice of carbon atoms in graphene does not allow the transmission of small gas molecules. In addition, its outstanding mechanical flexibility and optical transmittance are expected to be useful to overcome the current mechanical limit of the inorganic materials. In this paper, we reported the measurement of the water vapor transmission rate (WVTR) through the 6-layer 10 × 10 cm<SUP>2</SUP> large-area graphene films synthesized by chemical vapor deposition (CVD). The WVTR was measured to be as low as 10<SUP>–4</SUP> g/m<SUP>2</SUP>·day initially, and stabilized at ∼0.48 g/m<SUP>2</SUP>·day, which corresponds to 7 times reduction in WVTR compared to bare polymer substrates. We also showed that the graphene-passivated organic field-effect transistors (OFETs) exhibited excellent environmental stability as well as a prolonged lifetime even after 500 bending cycles with strain of 2.3%. We expect that our results would be a good reference showing the graphene’s potential as gas barriers for organic electronics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-6/acsnano.5b01161/production/images/medium/nn-2015-01161h_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b01161'>ACS Electronic Supporting Info</A></P>

Development of Treatement Agents Synthezied by Acid Mine Drainage Sludge (amds) for Adsorption of As(iii) and As(v) in Contaminated Soil: a Field Study

Jaeyoung Choi,Hongkyun Lee,Woo-Ram Lee,Hyun-Shik Yun,Eundo Gee,Young-Tae Park,Yoon-Su Kim,Jin-Soo Lee 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Radiopaque markers and hydrogram in feline alimentary lymphoma

Choi, Jihye,Lee, Jinsoo,Jang, Jaeyoung,Choi, Heeyeon,Seo, Jimin,Lee, Minjung,Kim, Hyunwook The Korean Society of Veterinary Science 2012 大韓獸醫學會誌 Vol.52 No.2

Radiography, ultrasonography with hydrogram, and contrast studies using radiopaque markers were applied to evaluate alimentary lymphoma in two cats. The hydrogram facilitated the differentiation of pseudo-thickening from true wall thickening, and enabled an evaluation of wall layering and lymph nodes. In case 1, mechanical obstruction of the duodenum was confirmed with barium-impregnated polyethylene spheres (BIPS), a radiopaque marker; however, results obtained in case 2 were not as definitive. We expect that hydrograms and BIPS can be used as valuable alternative methods to evaluate the gastrointestinal (GI) tract although further studies in cases involving GI tumors are needed.

A Feedback Wideband CMOS LNA Employing Active Inductor-Based Bandwidth Extension Technique

Choi, Jaeyoung,Kim, Sanggil,Im, Donggu THE KOREAN INSTITUTE OF SMART MEDIA 2015 스마트미디어저널 Vol.4 No.2

A bandwidth-enhanced ultra-wide band (UWB) CMOS balun-LNA is implemented as a part of a software defined radio (SDR) receiver which supports multi-band and multi-standard. The proposed balun-LNA is composed of a single-to-differential converter, a differential-to-single voltage summer with inductive shunt peaking, a negative feedback network, and a differential output buffer with composite common-drain (CD) and common-source (CS) amplifiers. By feeding the single-ended output of the voltage summer to the input of the LNA through a feedback network, a wideband balun-LNA exploiting negative feedback is implemented. By adopting a source follower-based inductive shunt peaking, the proposed balun-LNA achieves a wider gain bandwidth. Two LNA design examples are presented to demonstrate the usefulness of the proposed approach. The LNA I adopts the CS amplifier with a common gate common source (CGCS) balun load as the S-to-D converter for high gain and low noise figure (NF) and the LNA II uses the differential amplifier with the ac-grounded second input terminal as the S-to-D converter for high second-order input-referred intercept point (IIP2). The 3 dB gain bandwidth of the proposed balun-LNA (LNA I) is above 5 GHz and the NF is below 4 dB from 100 MHz to 5 GHz. An average power gain of 18 dB and an IIP3 of -8 ~ -2 dBm are obtained. In simulation, IIP2 of the LNA II is at least 5 dB higher than that of the LNA I with same power consumption.

Kinetic Analysis of Electron Transport in Hot-cathode Penning Ionization Gauge Sources

Jaeyoung Choi,June Young Kim,Kyoung-Jae Chung,Y. S. Hwang 한국진공학회 2020 한국진공학회 학술발표회초록집 Vol.2020 No.2