Earticle

In this study, based on the most used single board computer, Raspberry Pi, the MEMS-type accelerometer ADXL345 and the iPhone 12 accelerometer were used to measure the acceleration of a single DOF structure, and based on this, the effectiveness of identifying the dynamic characteristics of the accelerometer was verified. Acceleration measurement results were compared with KS48C, an IEPE type accelerometer. As a result of accelerometer measurement, the Raspberry Pi-based ADXL345 and iPhone 12 accelerometer were larger than the KS48C at the initial price, but showed similar results as time passed. The natural frequency measurement result was the same for all accelerometers at 1.419Hz. All damping ratio estimation results were similar. Based on the experimental results, the validity of dynamic characteristic identification of the Raspberry Pi-based MEMS type accelerometer and the iPhone 12 accelerometer was verified.

This paper describes the architecture and operation concept of simulation environment (AddSIM: Adaptive distributed parallel simulation environment based on interoperable and reusable models) to enhance the interoperability and reusability of models. The simulation environment makes it possible to search and use component-type models stored in local or remote resource repositories, which enable users to assemble or reconfigure models by plug-in and play style easily. To improve the reusability, interoperability, and composability of models, the concept to separate a model from a simulation engine is applied and the standard structure and modeling framework of models are presented. This proves that a model can be developed independently and linked with a simulation engine using API.

Aim First time mothers faced with a continuously crying infant, who do not know how to stop their child from crying, are at risk of developing anxiety and other types of Emotional Unrest. Because continuous Emotional Unrest may lead to an emotional crisis, it is important for healthcare providers to understand causal factors associated with Emotional Unrest among first time mothers faced with a persistently crying infant 6?7 weeks postpartum. Methods A cross-sectional survey was carried out on a study population of 217 first time mothers with infants aged 6?7 weeks. A self-administered questionnaire was used to measure Emotional Unrest, Neighborhood Social Organization, Effective Parenting Support, Understanding of Crying and the Effect of Information Available on Crying, Current Parenting Environment and Characteristics of the Mother and Child. Potential causal factors for Emotional Unrest were explored using structural equation modeling. Results One hundred and thirty two (60.8%) of the mothers experienced persistent crying in the period 6?7 weeks after the birth of their child and 108 (49.7%) mothers experienced Emotional Unrest. Factor analysis revealed five important constructs to be causal factors of Emotional Unrest: Effective Parenting Support, Effective Assistance with Regard to Crying, Confused by Information, Neighborhood Social Organization and Feelings of Fatigue and Anxiety. Structural equation modeling indicated that Effective Parenting Support, Effective Assistance with Regard to Crying, Confused by Information and Neighborhood Social Organization affect Feelings of Fatigue and Anxiety, which then leads to Emotional Unrest. Conclusion This study demonstrated that it will be necessary in future for health-care workers to provide early intervention, such as accurate information about crying as well as concrete and appropriate response measures for dealing with crying. Furthermore, in motherhood/parenting classes and the discharge guidance conducted at birthing centers, it will be necessary to provide guidance on what kind of effective support and local area resources are available to parents following the birth of their child.

Purpose: This study aimed to develop a model for estimating the quality of life mediated by adaptation to changes experienced after stomach cancer diagnosis and surgery in patients with gastrectomy and to verify the model based on the Cancer Survivor Adaptation Model by Naus et al. (2009) and literature reviews. Methods: Data was collected from 297 gastric cancer patients who underwent a gastrectomy at an outpatient clinic of two university hospitals in Daegu city from May to August, 2016. The exogenous variableswere perceived gastrointestinal symptoms, self-efficacy, anxiety, social support, and spiritual well-being. The endogenous variableswere adaptation and quality of life, and adaptationwas themediating variable. For data analysis, structural equation modeling was performed using IBM SPSS 21.0 and AMOS 18.0. Results: The fitness parameters of the final model showed a reasonable fit to the data. Based on R2, the exogenous variables explained 73.9% of the quality of life of stomach cancer patients who underwent surgery, through the mediation of adaptation; adaptation alone explained 73.5% of quality of life. Adaptation of stomach cancer patients with gastrectomy was a factor that strongly influenced their quality of life. Conclusion: It is important for gastric cancer patients with gastrectomy to adapt well to changes after surgery in order to improve the quality of life. Nursing interventions to aid successful adaptation would ultimately exert positive influences and improve the patients’ quality of life.

We propose a fast and accurate numerical method to price European swaptions in a multi-factor Gaussian term structure model that can speed up the calibration to the volatility surface. Pricing an interest rate option in such a multi-factor term structure model involves evaluating a multi-dimensional integration of the underlying claim's payo on a domain where the payo is positive. In our method, we approximate the exercise boundary of the state variables as a hyperplane tangent to the maximum probability point on the boundary and simplify the multi-dimensional integration into an analytic form. The maximum probability point can be found using the gradient descent method. We show that the quality of our method is superior to the result of previous studies by directly comparing them to the exact price obtained from the numerical integration.

The main purpose of this paper is to derive the analytic valuation formulae of …xed range accrual notes (FiRAN) and ‡oating range accrual notes (FlRAN) in the context of an a¢ ne term-structure model incorporating stochastic long-run mean, stochastic volatility and jumps according to the empirical …ndings of An- dersen et al.(2004). We propose a quasi-analytic pricing and hedging solutions for range accrual notes and these solutions are demonstrated in sensitivity analysis. Our numerical results show all these three factors signi…cantly a¤ect the values and hedging strategies of range accural notes, and the factor of stochastic mean plays the most important role in either valuation or hedging.

본 연구는 보건계열 대학생의 토익학습에서 자아요인, 스트레스요인, 적응 및 통제요인, 시험불안 및 학습몰입과 학업소진의 관련성을 파악하고 학업소진에 미치는 융복합적 영향을 분석하였다. 조사대상은 임의로 선정된 J 지역 1개 대학의 토익학습반에 참여하는 보건계열 대학생 291명으로 하였으며, 자료수집은 2017년 4월 3일부터 4월 14일까지 자기기입식 설문지를 통해 이루어졌다. 공분산 구조분석 결과, 자아요인, 스트레스요인, 적응 및 통제요인, 시험불안, 학습몰입 및 학업소진의 인과관계가 확인되었다. 경제적스트레스 및 취업스트레스, 시험불안, 학습몰입과 자아요인이 학업소진을 설명하는 squared multiple correlations은 98.8%로 나타났다. 이상의 연구결과를 볼 때, 보건계열 대학생의 토익학습의 학업소진을 낮추기 위해서는 이들 요인들을 관리하는 노력이 필요하다. 이러한 결과는 보건계열 대학생의 토익학습의 학업소진을 낮추는 토익학습 교육과정 및 교과목 개발에 활용이 기대된다. 향후연구에서는 학업소진에 영향을 미치는 추가요인에 대한 분석이 필요하다.

This study investigates convergent influence on Self Factors(SF), Stress Factors(STF), Resilience & Control Factors(RCF), Test Anxiety(TA), Learning Flow(LF) and academic burnout among Health College Students in TOEIC class(HCST). The survey was administered to 291 HCST from 1 college located in J area during the period from April 3, 2017 to April 14, 2017. The structured self-administered questionaries were used. With the analysis of covariance structure, we could confirm relationship among the six factors such as SF, STF, RCF, TA, LF and academic burnout. The results of the study indicate that the efforts, to manage these factors, are required to decrease the academic burnout of HCST. Squared multiple correlations, which explain the academic burnout related with the stress from economic pressure and job seeking, test anxiety, learning flow and self factors, were 98.8%. The results are expected to be useful for the development of TOEIC learning curriculum and course to decrease the academic burnout of HCST. In the following study, the analysis about additional factors of influence on academic burnout will be needed.

The objective of this study is to find the effective stiffness and compressive strengths of a unit-cell pinwheel truss and double pinwheel truss model designed following a double helical geometry similar to that of the DNA (deoxyribonucleic acid) structure in biology. The ideal solution for their derived relative density is correlated with a ratio of the truss thickness and length. To validate the relative stiffness or relative strength, ABAQUS software is used for the computational model analysis on five models having a different size of truss diameter from 1mm to 5mm. Applied material properties are stainless steel type 304. The boundary conditions applied were fixed bottom and 5 mm downward displacement. It was assumed that the width, length, and height are all equal. Consequently, it is found that the truss model has a lower effective stiffness and a lower effective yielding strength.

인공지능은 다양한 분야에서 사람을 대신하여 성과를 보여준다. 게임 분야에서도 인공지능은 다양한 방면 으로 사용된다. NPC(Non Player Character) 제작, 게임 난이도, 콘텐츠 생성 등의 분야에서 활용되고 있다. 그 러나 게임에서 사용되는 인공지능은 우수한 성과를 보여주며 사람을 이기기 위해 연구된다. 우수한 인공지능 모델이 게임에 존재하여 게임의 난이도가 상승하게 되면 플레이어가 게임에 흥미를 잃는 경우도 있다. 따라 서 본 논문의 목적은 사람과의 대결이 아닌 사람을 서포트 하는 인공지능의 개발이다. 현재 모바일 시장의 게임에는 자동 사냥 시스템이 존재한다. 게임에서 이 시스템은 난수 방식을 사용하기 때문에 효율이 떨어진 다. 그러므로 본 논문에서는 병렬구조의 DNN 모델을 사용하여 효율적인 자동 사냥 시스템을 구축한다. 새로 구축한 모델과 기존에 사용하던 난수 방식의 모델을 게임을 통해 비교한다.

AI shows performance on behalf of people in various fields. In games, AI is used in many ways. It is used in fields such as NPC (Non Player Character) production, game difficulty, and content creation. However, the AI used in the game shows excellent performance and is researched to beat people. When a good AI model exists in a game, increasing the difficulty of the game, the player may lose interest in the game. Therefore, the purpose of this paper is to develop artificial intelligence that supports people, not confrontation with people. Currently, there is an auto play system for games in the mobile market. In games, this system is not efficient because it uses a random method. Therefore, in this paper, we build an efficient auto play system using parallel DNN model. The newly constructed model and the existing random number model are compared through the game.

This paper first dichotomizes risk drivers into “stock” or “flow” attributes. Stock risk drivers are prices of tradable securities and flow risk drivers are rates represented by the stochastic movements of a term structure of securities. This paper then shows that the Black Scholes model is the relative valuation model for the stock risk drivers while the proposed unified model is for the flow risk drivers. The unified model can be described in the Ho-Lee model framework. We apply this model to five different flow risk drivers: interest rate, credit risk, liquidity risk, energy risk, and inflation risk. We then show that the unified model provides an analytical framework for securities that are subjected to several of these flow risk drivers, offering many applications. For example, the 2008 financial crisis clearly shows the importance of the use of a unified model in enterprise risk management. The crisis demonstrates that risk management should not take a silo approach to manage each flow risk driver, such as interest rate risk and credit risk. We propose an integrated approach to manage risks using the unified model.

이 연구는 이웃의 환경이 어린아동들과 청소년들의 마리화나 사용에 미치는 영향에 대 해 분석한 연구이다. 이 연구의 분석을 위해서 에이커스가 제안한 사회구조와 사회학습이 론이 이론적 배경으로 사용되었다. 이 연구는 특히 에이커스의 이론 중 중요한 몇 가지 가 정을 검증하는 데 집중한다. 사회구조와 사회학습이론 중 친구들과의 차별적 접촉의 영향 이 어린아동들과 청소년들의 마리화나 사용에 영향을 미치는 데 환경적 영향을 중재하는 지 여부를 검증하고자 하는 목적이 있다. 특히, 차별적 접촉의 영향이 이미 비행을 저지르 는 나쁜 친구들과의 차별적 접촉이 증가할 때, 비행이나 약물남용의 가능성이 높아진다는 것은 잘 알려져 있으나, 준법적이고 모범적인 친구들과의 차별적 접촉의 경우, 비행이나 약물남용의 가능성이 낮아지는 지 여부에 대해서는 연구가 거의 수행되지 못하였다. 따라 서 이 연구에서는 에이커스 이론 가운데 이 부분에 대한 검증에 초점을 맞추었다. 이 연구 에서는 미국 시카고의 범죄와 환경에 관한 대형 연구프로젝트인 PHDCN의 연구에 사용 된 데이터를 사용하여 총 1,791의 어린아동들과 청소년들을 대상으로 다중회귀분석기법을 사용하여 분석하였다. 연구결과, 사회구조와 사회학습이론에 대한 제한적이지만 일반적으 로 지지하는 결과가 나타났다. 즉, 분석결과 차별적 접촉의 영향이 어린아동들과 청소년들 의 마리화나사용에 대해 영향을 미치는 데, 이론에서 주장한 바와 같이 중재하는 역할을 할 뿐만 아니라 조정하는 역할도 하는 것으로 나타났다. 이 연구의 공헌과 앞으로의 연구 의 방향 등에 대한 논의 등이 결론과 논의 부분에서 제시되었다.

This study investigates the effects of neighborhoods and different peer association on children and adolescents’ marijuana use. For doing so, this study utilized Akers’ SSSL (Social Structure and Social Learning) model to understand the relationship and partially test the SSSL model. Especially, this study has purposes to examine the mediation effects of one of core propositions of the differential association with deviant friends as well as conforming peers on marijuana use. The SSSL model, theoretically, predicts that differential association with deviant peers as well as with conforming peers mediates social disorganization of neighborhoods on adolescent drug use in a different direction. Using the data from 1,791 children and adolescents residing in Chicago, this study used multilevel regression analysis with robust standard error. The findings of the study suggests mixed supports for the SSSL model. That is, the results indicates there are not only mediation effects but also moderation effects of differential association on children and adolescents' drug use in the data. Contributions and suggestions for the future studies were discussed in result and discussion.

Since the Christianity had been introduced to Korea, the Korean church has been well known to the world for its rapid growth. In addition, Korea is now the second high-ranking country in numbers that sends missionaries to the world. However, it does not mean that the evangelization and mission work in Korea have been finished. Korea took a radical turn into more secular and more plural society in 1980s. The forces of postmodernism and globalization have seriously affected to Korean people since the early 1990s. Since the mid-1990s, the number of church members in Korea has begun to decrease. One of the common problems that Korean churches face today is the rapid decrease of teenagers and young adults who attend church. Korean churches should be sensitive to current crises and respond to various challenges from the world, which is very secularized, postmodernized, and globalized. In a word, Korea still remains a mission field today and a apostolic church model is asked for performing more effective missions in Korea. In this article, the researcher discusses the apostolic ecclesiology, particularly its structure. The definition, identity, and characteristics of the apostolic church are discussed, and then a model of the biblically faithful and functionally effective structure of the apostolic church is detailed with suggestions for Korean churches to be truly missional.

Employability serves as a pivotal bridge between the realm of education and vocational workforce. Hence, it is imperative for higher education institutions to formulate and execute strategies aimed at enhancing the employability of their students. However, in South Korea, research on employability is still relatively underdeveloped. This study aims to investigate the suitability of applying the CareerEDGE model to Korean universities, a model firmly established in the realms of employability research and applications within the higher education sector. Survey responses were collected from a cohort of 271 students enrolled in their third and fourth years at three Korean universities. Confirmatory factor analysis substantiates the appropriateness of the CareerEDGE model for Korean students. Subsequently, regression analysis reveals that all five constructs encompassed within the CareerEDGE model exert a significant influence on employability, with career development learning and emotional intelligence emerging as the most salient contributors. This outcome underscores the importance of psychological components, in conjunction with the conventional emphasis on skills and knowledge, in augmenting employability. In conclusion, the findings and implications of this study are anticipated to make substantive contributions to the enhancement of employability education in Korean universities and the fortification of career development initiatives for university students.

This study investigated the factor structure of the listening and reading sections of a TOEIC practice test using a bifactor model and a two-tier model that are based on a full-information item factor analysis. The data was drawn from 3158 college students’ responses to a TOEIC practice test. The results showed that the listening factor is essentially unidimensional whereas the reading factor is bidimensional: one primary factor for reading comprehension and a minor factor for vocabulary and grammar. The analyses also suggested that the listening and reading factors are highly correlated but distinctive skills. Subsequently these factor structures were compared and contrasted to the results from previous validation studies of the TOEIC test in the literature, Finally pedagogical implications were discussed

Purpose: The purpose of this study was to set up a hypothetical model to explain causal relationships among influential variables in the mother-child relationship for Korean infants and toddlers and their mothers. The research was based on Barnard’s (1978) mother-child relations model, and goodness-of-fit was examined. Methods: The participants were 207 mothers with infants or toddlers. Data were analyzed using SPSS and AMOS programs. Results: Regarding the influence of the variables on the mother-child relationship between infants and toddlers and their mothers, social support had a 75% explanation of mother-child relationships, and attachment had a 58% explanation of social support. Attachment had both direct and indirect effects on the mother-child relationships, and social support had direct and total effects on the mother-child relationships. Among child-related variables, child temperament had a moderating effect on the mother-child relationships. Conclusion: The findings indicate that the model has utility in developing effective nursing intervention methods to boost mother-child relationships between infants and toddlers and their mothers.

본 연구의 목적은 기존 다차원적 완벽주의 척도를 사용하여 이차원적 완벽주의 구성개념을 확인하고 위계적 모형의 타당성을 검증하는 것이다. 본 연구의 완벽주의 척도는 FMPS(Frost, Marten, Lahart, & Rosenblate, 1990), HMPS(Hewitt & Flett ; 1991), 그리고 APS-R(Slaney, Ashby & Trippi, 2001)를 사용하여 구성하였다. 세 척도에서 개념과 진술이 같은 문항을 제외하고, 측정하려는 의미를 유지하면서 이해하기 쉽도록 문항을 수정하여 49개 문항으로 구성하였다. 자료는 탐색적 요인분석과 위계적 모형의 확인적 요인분석을 위해 두 차례 수집하였다. 1차 질문지는 4년제 대학의 300명, 2차 질문지는 262명의 학부생에게 수집하였다. 1차 질문지는 49개 문항으로 구성하였다. 2차 질문지에는 가상 취업준비 상황 지문을 포함시켰다. 탐색적 요인분석 결과로 4개의 구성요인을 추출하였다. 제 1요인 ‘정리정돈/질서’, 제 2요인 ‘불일치’, 제 3요인 ‘절대적 성공추구’, 제 4요인 ‘높은 기준’이다. 네 개의 1차 요인들이 이차원적 완벽주의 구성개념에 적합한지를 검증하기 위해 위계적 모형에 대한 확인적 요인분석을 실시하였다. 위계적 2요인 모형의 적합도는 적절하였으며 2차 요인이 1차 요인에 미치는 영향력은 모두 유의하였다. 본 연구의 의의는 완벽주의 척도의 위계적 2요인 모형이 타당함을 확인한 것이다. 마지막으로 연구의 시사점과 앞으로의 연구방향을 논의했다.

The purpose of this study was identified The two-dimensional perfectional construction and validate hierarchical two factor model. For this study questionnaire including 3 perfectional Scales, FMPS(Frost, Marten, Lahart, & Rosenblate, 1990), HMPS(Hewitt & Flett; 1991), and APS-R(Slaney, Ashby & Trippi, 2001) was constructed. In this process 49-items were selected. Survey for data collection was conducted twice for exploratory and confirmatory factor analysis. 300 university student participated in the first survey and 262 university student participated in the second survey. As a result of exploratory factor analysis, 4 factors were abstracted. These factors are order, discrepancy, absolute pursuit of success and high standards. The confirmatory factor analysis was used for verification that four lower factors is fitted two-dimensional perfectionism scale. The fitness of hierarchical 2 factor model was appropriated. The effect of higer factors on lower order factors was statistically significant. Worthwhile of this study is to confirm validation for hierarchical two factor model of perfectionism scale. Implication and limitation of the study and suggestions for future study were discussed.

한반도 남동부 해역에서 취득한 OBS 자료를 이용하여 굴절파 및 광각 반사파 모델링 및 주시 역산을 수행하여 해당 해역의 심부 2차원 속도 및 층서모델을 제작하였다. 주시 상반성 분석을 통해 탐사자료 주시의 적합성 시험을 실시하고, 같은 자료를 이용하여 탄성파 주시 토모그래피 및 타우-합(-sum) 역산 기법을 적용하여 초기 속도 모델을 제작하였다. 모델링 및 역산은 지질 모델을 두 부분으로 나누어 실시하였는데, 1)굴절파만을 이용하여 퇴적층 및 상부 지각의 구조를 구하고 2)굴절파와 함께 PcP, PmP를 발췌하여 하부 지각 및 모호의 구조를 구하였다. 그 결과 기반암의 심도가 모델 전반에 걸쳐 3.2∼6 km 심도로 걸쳐있고 기반암 상부 속도는 평균 5 km/s임을 알 수 있었다. 또한 퇴적층을 제외한 지각의 두께는 약 7.8∼16 km의 분포를 보임을 확인하였다. 최종 결과에 대한 모델 평가를 실시하여 그 결과가 적절한 해상도를 가지고 도출된 결과임을 보였다.

2-D crustal structure of the southeastern Korean margin was derived through 2-D traveltime modeling and inversion using OBS refraction and wide-angle reflection data. The reciprocity test was carried out to check validity of the data, and initial model was built based on the traveltime tomography and -sum inversion. Crustal modeling and inversion were in two parts; 1) Only refraction phase was used for sedimentary layer and upper crust. 2) Refraction, PcP, and PmP phases were used for lower crust and Moho. The lower boundary of the sedimentary layer was shown up at 3.2∼6 km depth, and the average velocity of the bedrock below is 5 km/s. Thickness of the crust was in the range of 7.8∼16 km. Resolution values calculated during inversion indicated that the final model was well resolved.

콘크리트 비파괴 검사법 중 탄성파를 이용하는 충격반향기법을 사용할 경우, 이론적인 역산기법에 의한 토모그래피를 작성하였다. 탄성파 탐사에서의 역산기법은 초동주시 역산법과 전파형 역산법이 있다. 초동주시 역산법은 초기도달시간을 이용하는 방법으로 파선법, 유한요소법, 유한차분법 등을 이용하여 초기도달시간을 계산할 수 있다. 전파형 역산법은 초동주시 역산법에 비해서 보다 나은 정확성을 보여주지만 적당한 초기치를 주어야만 하는 한계를 보여주었다. 본 연구에서는 초기치 문제를 해결하기 위하여 보정형 역산법을 콘크리트 구조물 모형에 시도하였다.

Tomograph used corrected inversion method for concrete structure model using impact-echo method was tried. There are traveltime inversion method and full-wave inversion method on seismic data interpretation. The traveltime seismic method uses first arrival time which is calculated by ray method, finite element method, finite difference method and so on. Full-wave inversion is the best method in terms of model resolution and overcomes limitations imposed by the high-frequency restriction in traveltime inversion and the weak scattering approximation of Born methods. But this method have difficulties and weak points in accuracy and selection of intial velocity value. In this study, corrected seismic inversion method which is able to solve the above difficulties is applied to theoretical pier model to calculate tomography.

본 연구는 이제 막 오픈형에 발을 내딛는 IPTV의 오픈형 플랫폼 전략이 갖는 의미와 방향을 모색하는 것을 목적으로 한다. 이를 위해 먼저 오픈형 플랫폼과 관련한 이론적 논의들을 살펴보고, 이론에 근거한 오픈형 플랫폼 유형별 전략 시나리오 및 관련 사례들의 오픈형으로 가게 된 요인들과 관련 이슈들에 대해 살펴보았다. 그 다음에는 미국, 유럽의 대표적 IPTV 사업자들의 오픈형 추진 배경 및 의미를 분석하고, 마지막으로 국내 IPTV 사업자들의 오픈형 플랫폼 전략의 방향성을 제시하고 있다. 이론적 탐색을 통해 본 연구는 오픈형이 특히 공급측 이용자인 콘텐츠 사업자 및 애플리케이션 개발자들의 혁신을 향상시키고 서비스의 다양성을 가능하게 한다는 점을 발견하였으며, 이를 기반으로 한 유형별 전략 시나리오 하에서 최근 해외 주요 IPTV들이 기존 사업자와의 시장 경쟁 및 시장 정체로 인해 이러한 유형의 오픈형을 받아들이기 시작했음을 알게 되었다. 이들의 전략 추진이 주는 의미는 N스크린 전략의 완성, 범위의 경제 제고, 콘텐츠 및 기술 R&D 비용 절감, 콘텐츠 총량의 확대, 그리고 잠재적 및 기존 경쟁자에의 대응 등이며, 국내 통신기업에 의해 최근 발표된 오픈형 IPTV도 이러한 전략적 방향성을 가지는 것이 바람직함을 논의하고 있다.

The purpose of this study is to give strategic implications and directions by analyzing global major IPTV operators’open platform strategies. For this purpose, it discusses the platform-related theories, especially the conceptual approach about ‘opening platforms’ initiated by Eisenmann, Parker and Van Alstyne in 2008. The platform-mediated networks encompass several distinct types of participants, such as end users, complements, platform providers facilitating end users, access to complements, and platform sponsors developing platform technologies. Each of these roles can be opened, that is, can be structured to encourage participation. Based on the theoretical background, this paper reviews factors that motivate decisions to open platforms. At the platform provider and sponsor levels, horizontal strategic decisions entail interoperating with established rival platforms, licensing additional platform providers, or broadening sponsorship. With respect to complements, vertical strategic decisions to open a platform involve backward compatibility with prior platform generations, securing exclusive rights to certain complements, or complements envelopment. Several cases in IT industry are exampled. Lastly, it is concluded by analyzing global major IPTV platforms that over time the recent market saturation tends to push IPTV toward opening platforms by shared responsibility for serving complements and end users. Its strategic implications are completing the N-Screen strategy, expanding the economies of scope, saving the R&D cost, diversifying the contents, and meeting competition with potential entrants and established rivals.