Adaptive Feedforward Compensation for High Power Amplifier Nonlinearity Using a Digital Signal Processing Technique

Junseok Oh,Min Kim,Jongman Gim,Changsoo Eun 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

We propose a compensation scheme for high power amplifier nonlinearity using a digital signal processing technique and a feed forward configuration. Since we adopte a feedforward configuration, we can apply our scheme to the existing transmitter with little modification. Moreover, system instability that might arise due to feedback is avoided. The proposed scheme is applied to the mobile WiMax system which uses OFDM modulation. We obtained more than 20 ㏈ suppression in out-of-band spectral regrowth.

The Difference of Awareness between Public Institutions and Private Enterprises for Cloud Computing Security

Junseok Oh,Young Bae Yoon,Jong Ryeol Suh,Bong Gyou Lee 보안공학연구지원센터 2012 International Journal of Security and Its Applicat Vol.6 No.3

A Technical Approach for Suggesting Research Directions in Telecommunications Policy

( Junseok Oh ),( Bong Gyou Lee ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.12

The bibliometric analysis is widely used for understanding research domains, trends, and knowledge structures in a particular field. The analysis has majorly been used in the field of information science, and it is currently applied to other academic fields. This paper describes the analysis of academic literatures for classifying research domains and for suggesting empty research areas in the telecommunications policy. The application software is developed for retrieving Thomson Reuters` Web of Knowledge (WoK) data via web services. It also used for conducting text mining analysis from contents and citations of publications. We used three text mining techniques: the Keyword Extraction Algorithm (KEA) analysis, the co-occurrence analysis, and the citation analysis. Also, R software is used for visualizing the term frequencies and the co-occurrence network among publications. We found that policies related to social communication services, the distribution of telecommunications infrastructures, and more practical and data-driven analysis researches are conducted in a recent decade. The citation analysis results presented that the publications are generally received citations, but most of them did not receive high citations in the telecommunications policy. However, although recent publications did not receive high citations, the productivity of papers in terms of citations was increased in recent ten years compared to the researches before 2004. Also, the distribution methods of infrastructures, and the inequity and gap appeared as topics in important references. We proposed the necessity of new research domains since the analysis results implies that the decrease of political approaches for technical problems is an issue in past researches. Also, insufficient researches on policies for new technologies exist in the field of telecommunications. This research is significant in regard to the first bibliometric analysis with abstracts and citation data in telecommunications as well as the development of software which has functions of web services and text mining techniques. Further research will be conducted with Big Data techniques and more text mining techniques.

Marketability Analysis of Seoul Landmark Pass

Junseok Oh(오준석),Sunhee Kwak(곽선희),Hanbyeol Kim(김한별),Heesoo Jeon(전희수,Jonghwa Kim(김종화) 한국산업경영시스템학회 2017 한국산업경영시스템학회지 Vol.40 No.1

As the number of tourists visiting Seoul are continuously increasing, the demand of an integrative tour pass is also increasing. However, only a few tour passes are available for the tourists in Seoul. In this paper, we propose a new tour pass called “Seoul Landmark Pass” targeting foreign individual travelers and investigate the marketability of the proposed tour pass. For the configuration of the Seoul Landmark Pass we listed 17 candidate attractions charging entrance fee in Seoul, referring to e-guidebook on Visit Seoul web site. Among them we selected 6 attractions using the checklist with the attributes that foreign tourists would prefer. We also performed SWOT analyzes on existing tour passes to determine the benefits to be included in the proposed tour pass. To investigate the marketability of the proposed tour pass we have surveyed the foreign individual tourists in Seoul. Using the survey data, we have analyzed the intent of purchase by age, visiting period, visiting purpose, frequency of visit, and nationality to identify target customers. The results show that the intent of purchase is high among the Chinese tourists at the age of twenties who visited Seoul for the first time or second times. Also, the individual tourists prefer to bundle T-money card with the proposed tour pass. Finally, we have provided a brief review of the Price Sensitivity Measurement (PSM) method and applied PSM to determine the acceptable price range and the optimal price of the proposed tour pass. The optimal price of the proposed tour pass is determined at 53,000 won including T-money card.

금속폼 필터의 3차원 유동해석프로그램 개발에 관한 연구

오준석(Junseok Oh),이정민(Jeongmin Lee),김구환(Kuhwan Kim),우민호(Mino Woo) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

DPF systems have been adopted due to the reinforcement of the emission regulation over the world. This easy studies a application of 3D CFD program using metal foam filter. In the result, it is verified that soot filtration and pressure drop over metal foam filters can be predictable with 3D CFD program

DNA 서열 분석을 위한 클라우드 컴퓨팅 기반 지능형 미들웨어 설계

오준석 ( Junseok Oh ),이윤재 ( Yoonjae Lee ),이봉규 ( Bong Gyou Lee ) 한국인터넷정보학회 2014 인터넷정보학회논문지 Vol.15 No.1

차세대 유전체 해독 기술과 자동화 기술이 발전하면서 DNA 서열 분석 환경이 개선되고 있지만, 아직까지 제한된 컴퓨팅 리소스는 분석시간 단축의 장애요인으로 작용하고 있다. 대부분의 과학 워크플로우 시스템은 수 많은 기능들이 특정 시스템 환경에 맞추어 구현되어 있기 때문에 복잡하고 유동적이지 못하며, 이로 인해 기존 시스템의 컴포넌트들을 클라우드 환경의 새로운 시스템에 적용하기 어려운 한계를 지니고 있다. 본 연구에서는 대량의 DNA 데이터를 동시적으로 분석할 수 있는 가상 인스턴스 제공이 가능하며 시스템간의 상호 운용성을 개선시키기 위하여 웹 서비스, DBMS, 클라우드 컴퓨팅 기능을 지원하는 DNA 서열 분석용 미들웨어를 개발하였다. 본 연구에서 개발된 지능형 미들웨어는 DBMS를 사용하여 파이프라인 정보를 관리하고, 클라우드 환경에서 경량의 가상 인스턴스를 제공하며, 상호운용성 개선을 위하여 단순 URI와 XML을 기반으로 한 RESTful 웹서비스 기능을 제공한다. The development of NGS technologies, such as scientific workflows, has reduced the time required for decoding DNA sequences. Although the automated technologies change the genome sequence analysis environment, limited computing resources still pose problems for the analysis. Most scientific workflow systems are pre-built platforms and are highly complex because a lot of the functions are implemented into one system platform. It is also difficult to apply components of pre-built systems to a new system in the cloud environment. Cloud computing technologies can be applied to the systems to reduce analysis time and enable simultaneous analysis of massive DNA sequence data. Web service techniques are also introduced for improving the interoperability between DNA sequence analysis systems. The workflow-based middleware, which supports Web services, DBMS, and cloud computing, is proposed in this paper for expecting to reduceanalysis time and aiding lightweight virtual instances. It uses DBMS for managing the pipeline status and supporting the creation of lightweight virtual instances in the cloud environment. Also, the RESTful Web services with simple URI and XML contents are applied for improving the interoperability. The performance test of the system needs to be conducted by comparing results other developed DNA analysis services at the stabilization stage.

멀티모달 상호작용 중심의 로봇기반교육 콘텐츠를 활용한 r-러닝 시스템 사용의도 분석

오준석(Junseok Oh),조혜경(Hye-Kyung Cho) 제어로봇시스템학회 2014 제어·로봇·시스템학회 논문지 Vol.20 No.6

This paper introduces a robot-based learning system which is designed to teach multiplication to children. In addition to a small humanoid and a smart device delivering educational content, we employ a type of mixed-initiative operation which provides enhanced multi-modal cognition to the r-learning system through human intervention. To investigate major factors that influence people’s intention to use the r-learning system and to see how the multi-modality affects the connections, we performed a user study based on TAM (Technology Acceptance Model). The results support the fact that the quality of the system and the natural interaction are key factors for the r-learning system to be used, and they also reveal very interesting implications related to the human behaviors.

WICWIU.v3: 자연어 및 시계열 데이터 처리를 지원하는 C++ 기반 오픈소스 딥러닝 프레임워크

오준석(Junseok Oh),이찬효(Chanhyo Lee),우옥균(Okkyun koo),이세현(Sehyun Lee),김인중(Injung Kim) 한국정보과학회 2021 한국정보과학회 학술발표논문집 Vol.2021 No.12

WBAN 시스템에서 골드 코드를 이용한 다중 프리앰블의 성능 분석

오준석(Junseok Oh),류승문(Seung-Moon Ryu),은창수(Changsoo Eun) 大韓電子工學會 2010 電子工學會論文誌-TC (Telecommunications) Vol.47 No.8

골드 코드를 이용한 다중 프리앰블의 사용을 제안하고 성능을 분석한다. 다중 프리앰블은 한 시스템에서 모드 또는 응용의 종류에 따라 각자 다른 프리앰블을 사용하는 것이다. 골드 코드를 사용하는 다중 프리앰블의 수신은 최대 우도 (ML, maximum likelihood) 알고리듬을 사용하여 간단한 구조로 구현할 수 있으며, 골드 코드 특성은 상호 상관 특성이 우수하여 잡음에 강하다. 길이가 128 비트인 다중 프리앰블에 대한 최대 우도 검출 시 검출 실패 확률을 구하고, 컴퓨터 모의실험을 통해 성능 분석 및 타당성을 입증한다. 결과적으로 이론과 실험이 오차 범위 내에서 일치함을 확인하였다. We propose the use of multi-preambles using Gold codes and analyze its performance. The multi-preamble is a way of utilizing different codes for preambles according to operation modes or applications in a system. The receiver can be easily implemented using the maximum likelihood algorithm. The performance is robust against noise due to the good correlation characteristic of the Gold codes. We use 128-bit-long multi-preambles generated by 127 bit Gold codes in deriving the detection error probability and in verifying the validity through computer simulation. The results show that the theory and the experiment are in good agreement within the approximation error.

군 환경에서의 자원 가상화를 이용한 역할 기반 협업 소프트웨어 아키텍처

오준석(Junseok Oh),송세헌(Seheon Song) 한국정보과학회 2011 한국정보과학회 학술발표논문집 Vol.38 No.2B

미래의 군사 환경 및 작전은 분산 컴퓨팅 및 네트워크 능력을 활용하여 정보의 우위를 보장하고 협력하는 네트워크 중심전(NCW)으로 변모하고 있다. 미래 전장에서는 유/무인 장비의 협업을 통해 군사력의 효율을 증가시키고 신속한 정보/작전을 펼쳐 목적(Goal)을 달성할 수 있다. 그러나 이러한 유/무인 장비의 네트워크 결합은 모바일 단말 장치를 기반으로 이루어지기 때문에 이동성 컴퓨팅 파워 리소스 부족 배터리의 소모 등 제약점을 갖게 된다. 또한 협업하는 조직 구성의 일부가 소프트웨어의 실행 환경 변화에 적절히 대처하지 못하는 경우 작전 전체의 실패를 유발할 우려가 발생하며 이와 같은 관점에서 기존의 정적인 소프트웨어 시스템과는 달리 노드 및 구성요소들이 실행 시간에 동적으로 추가 수정 교체될 수 있는 적응성(Adaptability)이 중요한 성능으로 인식되고 있다. 본 논문에서는 최근 적응성 관련 연구에서 주목을 받고 있는 역할(Role)개념을 도입하고 모바일 단말장치의 자원적 한계성을 극복하기 위해 가상화와 접목하여 미래 군사 환경에서 적응성을 극대화하고 협업의 효율성을 증가시키기 위한 소프트웨어 아키텍처를 제안한다.