공간 모바일 장치를 위한 내장형 공간 MMDBMS의 설계 및 구현

박지웅,김정준,윤재관,한기준,Park, Ji-Woong,Kim, Joung-Joon,Yun, Jae-Kwan,Han, Ki-Joon 한국공간정보학회 2005 한국공간정보시스템학회 논문지 Vol.7 No.1

최근에 무선 통신의 발달과 더불어 모바일 컴퓨팅에 대한 관심이 높아지고 있다. 모바일 컴퓨팅은 사용자가 PDA, 노트북 등의 이동 가능한 모바일 장치를 휴대하고 무선 통신을 통해서 서버 컴퓨터와 자원을 함께 공유하는 환경이라 할 수 있다. 모바일 데이타베이스는 이러한 모바일 장치에 사용되는 데이타베이스를 말한다. 모바일 데이타베이스의 응용 분야로는 보험업무, 금융업무 의료 등이 있지만, 특히 사용자의 위치 정보를 활용하는 위치 기반 서비스(LBS: Location Based Service)가 중요한 응용 분야로 등장하고 있다. 이러한 모바일 환경에서 위치 기반 서비스를 제공하기 위해서는 공간 모바일 장치에서 대용량의 공간 데이타를 효율적으로 관리하기 위한 내장형 공간 MMDBMS(Main-Memory Database Management System)가 필요하다. 이에 본 논문에서는 기존의 PC용 MMDBMS인 HSQLDB를 확장하여 공간 모바일 장치에서 공간 데이타를 효율적으로 관리할 수 있는 내장형 공간 MMDBMS를 설계 및 구현하였다. 내장형 공간 MMDBMS는 ISO(International Organization for Standardization)의 공간 데이타 모델을 따르며, 공간 데이타 특성에 적합한 압축 기법인 산술 연산 코딩 기법을 제공하고, 공간 모바일 장치에 적합한 MBR 압축 및 해슁 기법을 이용한 공간 인덱스를 지원한다. 그리고, 공간 모바일 장치의 낮은 성능의 프로세서에서 공간 데이타 디스플레이 기능을 제공하고, 내장형 공간 MMDBMS와 GIS 서버 사이에서 공간 데이타 수입/수출의 성능 향상을 위한 데이타 캐슁과 동기화 기능을 지원한다. Recently, with the development of wireless communications and mobile computing, interest about mobile computing is rising. Mobile computing can be regarded as an environment where a user carries mobile devices, such as a PDA or a notebook, and shares resources with a server computer via wireless communications. A mobile database refers to a database which is used in these mobile devices. The mobile database can be used in the fields of insurance business, banking business, medical treatment, and so on. Especially, LBS(Location Based Service) which utilizes location information of users becomes an essential field of mobile computing. In order to support LBS in the mobile environment, there must be an Embedded Spatial MMDBMS(Main-Memory Database Management System) that can efficiently manage large spatial data in spatial mobile devices. Therefore, in this paper, we designed and implemented the Embedded Spatial MMDBMS, extended from the HSQLDB which is an existing MMDBMS for PC, to manage spatial data efficiently in spatial mobile devices. The Embedded Spatial MMDBMS adopted the spatial data model proposed by ISO(International Organization for Standardization), provided the arithmetic coding method that is suitable for spatial data, and supported the efficient spatial index which uses the MBR compression and hashing method suitable for spatial mobile devices. In addition, the system offered the spatial data display capability in low-performance processors of spatial mobile devices and supported the data caching and synchronization capability for performance improvement of spatial data import/export between the Embedded Spatial MMDBMS and the GIS server.

시공간 이동 패턴 추출을 위한 효율적인 알고리즘

박지웅,김동오,홍동숙,한기준,Park, Ji-Woong,Kim, Dong-Oh,Hong, Dong-Suk,Han, Ki-Joon 한국공간정보학회 2006 한국공간정보시스템학회 논문지 Vol.8 No.2

최근 들어 이동 객체의 이력 (history) 데이타에서 이동 객체의 이동 패턴, 즉 연속되는 시간 영역에서 반복적으로 발생되는 공간 이동 경로와 같은 다양한 지식을 추출하여 활용하는 응용 서비스의 활용성이 점점 증대되고 있다. 그러나 기존의 이동 패턴 추출 방법은 최소지지도(minimum support)가 낮은 경우에 많은 수의 후보 이동 패턴이 생성되고 이로 인하여 수행 시간과 소요 메모리가 급격히 증가하게 되는 단점이 있다. 본 논문에서는 대용량의 시공간 데이타 집합으로부터 이동 객체의 이동 패턴을 효율적으로 추출하기 위한 STMPE(Spatio-Temporal Moving Pattern Extracting) 알고리즘을 제안한다. STMPE 알고리즘은 시공간 데이타를 일반화시킴으로서 메모리 사용량을 최소화할 수 있으며, 단기 이동 패턴을 작성하여 유지하기 때문에 데이타베이스 스캔 횟수를 최소화할 수 있다. STMPE 알고리즘은 모든 부분에서 시간 정보를 갖는 다른 시공간 이동 패턴 추출 알고리즘보다 최소지지도가 낮아질수록, 이동 객체의 수가 증가할수록, 시간 분할 횟수가 많아질수록 더욱 뛰어난 성능을 보였다. With the recent the use of spatio-temporal data mining which can extract various knowledge such as movement patterns of moving objects in history data of moving object gets increasing. However, the existing movement pattern extraction methods create lots of candidate movement patterns when the minimum support is low. Therefore, in this paper, we suggest the STMPE(Spatio-Temporal Movement Pattern Extraction) algorithm in order to efficiently extract movement patterns of moving objects from the large capacity of spatio-temporal data. The STMPE algorithm generalizes spatio-temporal and minimizes the use of memory. Because it produces and keeps short-term movement patterns, the frequency of database scan can be minimized. The STMPE algorithm shows more excellent performance than other movement pattern extraction algorithms with time information when the minimum support decreases, the number of moving objects increases, and the number of time division increases.

복호길이 6인 Sliding-Window를 적용한 순방향 실시간 복호기 구현

박지웅,Park Ji woong 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.4c

IS-95와 IMT-2000 시스템에서 사용되고 있는 여러 종류의 길쌈 부호기를 부호율 1/2, 구속장 3인 길쌈 부호기로 한정하여, 비터비 복호기에 복호길이 6인 Sliding-Window와 Neural Network의 LVQ(Learning Vector Quantization)및 PVSL(Prototype Vectors Selecting Logic)을 적용하여 순방향 실시간 복호기를 구현한다. 이론적으로 제한된 AWGN 채널환경에서의 심볼 전송전력 $S/(N_{0}/2)=1$을 성능비교 조건으로 하여 순방향 실시간 복호기와 기존의 비터비 복호기의 $강\cdot연판정$ BER 성능과 하드웨어 구성을 $비교\cdot분석$하여, 본 논문에서 제시된 순방향 실시간 복호기의 BER 성능의 우수성과 비화통신의 장점 및 하드웨어 구성의 단순합을 검증하였다. In IS-95 and IMT-2000 systems using variable code rates and constraint lengths, this paper limits code rate 1/2 and constraint length 3 and realizes forward real-time decoder using Sliding-Window with decoding length 6 and PVSL(Prototype Vector Selecting Logic), LVQ(Learning Vector Quantization) in Neural Network. In comparison condition to theoretically constrained AWGN channel environment at $S/(N_{0}/2)=1$ I verified the superiority of forward real-time decoder through hard-decision and soft-decision comparison between Viterbi decoder and forward real-time decoder such as BER and Secure Communication and H/W Structure.

LVQ Network를 적용한 순방향 비터비 복호기

박지웅,Park Ji woong 한국통신학회 2004 韓國通信學會論文誌 Vol.29 No.12a

IS-95와 IMT-2000 시스템에서 사용되고 있는 여러 종류의 길쌈 부호기를 부호율 1/2, 구속장 3인 길쌈 부호기로 한정하여, neural network의 LVQ(Learning Vector Quantization)과 PVSL(Prototype Vector Selecting Logic)을 적용하여 비터비 복호기에서 사용되는 PM(Path Metric)과 BM(Branch Metric) 메모리 수와 산술$.$비교 연산량을 줄임으로써 시스템의 단순화와 순방향 복호를 가능하게 한다. 구속장의 확장성 여부와 관계없이 간단한 응용으로 기존의비터비 복호기에 적용할 수 있는 새로운 비터비 복호기의 구조와 적용 알고리즘을 제시하고, 제시된 비터비 복호기의 합리성을 VHDL 시뮬레이션으로 검증 후, 기존의 복호기와의 성능을 비교 분석한다. In IS-95 and IMT-2000 systems using variable code rates and constraint lengths, this paper limits code rate 1/2 and constraint length 3 and states the effective reduction of PM(Path Metric) and BM(Branch Metric) memories and arithmetic comparative calculations with appling PVSL(Prototype Vector Selecting Logic) and LVQ(Learning Vector Quantization) in neural network to simplify systems and to decode forwardly. Regardless of extension of constraint length, this paper presents the new Vierbi decoder and the appied algorithm because new structure and algorithm can apply to the existing Viterbi decoder using only uncomplicated application and verifies the rationality of the proposed Viterbi decoder through VHDL simulation and compares the performance between the proposed Viterbi decoder and the existing.

인터넷을 이용한 학원교육 및 관리 시스템에 관한 연구

박지웅 ( Ji-woong Park ) 한국고등직업교육학회 2000 한국고등직업교육학회논문집 Vol.1 No.1

Internet quickly change society environment as well as so far education environment. Recently government, industry, and an educational institution are carrying out technical development research to expel cyber education environment via Internet. But until now insufficiency of social infra composition and multimedia education contents has not revitalize cyber education system. The cyber education system be worse than the conventional education in a side view of quality. In this thesis, we designed and drove internet system Edumaster to supply information management of learner, convenient education management using question input unit and test paper generator, estimation management of learner, and open communication channel. And internet system Edumaster in conventional education environment assistant tool.

Enabling Melt or Solution-Processing of the Covalently Cross-Linked Polymer Network

Ji-Woong Park(박지웅),남준식 한국고분자학회 2023 한국고분자학회 학술대회 연구논문 초록집 Vol.48 No.1

알칼리 자극제 혼입 고로슬래그 미분말의 공극구조 및 미소수화열 분석

박지웅 ( Park Ji-woong ),박희곤 ( Park Hee-gon ),김우재 ( Kim Woo-jae ),이건철 ( Lee Gun-cheol ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2

In this study, fundamental properties by pore structure and heat of microhydration test were determined. As a result of pore structure analysis, BS(AA) specimen showed showed the maximum peak value of significantly lower incremental intrusion than the maximum peak value of incremental intrusion at smaller pore size than that of BS. As a result of heat of microhydration test, the maximum heating value was in the order of OPC > BS > BS(AA), and initial drying shrinkage and compressive strength of BS(AA) were expected to be improved.

상호작용하는 탄화수소-수소화염의 구조 및 오염물질 배출특성에 관한 수치계산 연구

박지웅(Ji-Woong Park),오창보(Chang Bo Oh) 한국연소학회 2011 KOSCOSYMPOSIUM논문집 Vol.- No.42

The structure and pollutant emission characteristics of interacting counterflow methane-hydrogen flames were investigated numerically using one-dimensional code, OPPDIF. For reference, numerical simulations were also performed for interacting methane-methane and hydrogen-hydrogen flames. GRI-v3.0 was used for the calculation of reaction rates in those interacting flames. The maximum temperature, flame width and local strain rates were investigated with the variation of the global strain rate. Only the maximum local strain rate evaluated at the thermal boundary of methane flame was correlated well with the global strain rate. Emission indices of CO, CO₂ and NO were evaluated to quantify the pollutant emission. Conventional emission indices based on the consumed fuel mass provided a good trend of pollutant emission with the variation of the global strain rate. New emission indices based on the lower heating value of consumed fuel was also introduced. It is expected that this new emission indices will be used as an useful tool to quantify the pollutant emission from the interacting flames especially in the respect of practical combustor design.

공기류측에 수증기가 첨가된 대향류 메탄 부분예혼합화염의 화염구조 및 소화한계에 미치는 복사효과

박지웅(Ji-Woong Park),오창보(Chang Bo Oh),김욱중(Ook Joong Kim) 한국연소학회 2012 KOSCOSYMPOSIUM논문집 Vol.- No.45

Radiation effects on the partially premixed methane flames diluted with water vapor in the air stream were numerically investigated. OPPDIF code and GRI-v3.0 were used in the numerical simulation. Adiabatic condition was compared with two different radiation models, optically-thin and WSGGM models. It was found that the radiation effect on the flame structure for the equivalence ratio (Ф) of 2.5 was less than Ф=1.5. Extinction limit was not affected significantly, however, local flame structure was markedly influenced by the radiation models as increasing the water vapor concentration.

보행 가능한 편마비 환자에서 편측 및 건측 하지 발목 관절의 인대와 힘줄의 초음파 비교

박지웅(Ji-woong Park),안재기(Jae-ki An),박용범(Yong-bum Park),배원식(Won-sik Bae) 한국전문물리치료학회 2010 한국전문물리치료학회지 Vol.17 No.2

In chronic ambulatory hemiplegic patients, structural changes might be developed at both ankles possibly due to unequal and repetitive weight bearing on tendons and ligaments. We examined ankles by sonography to find out structural changes of tendons and ligaments of both ankles in ambulatory hemiplegic patients. Nineteen ambulatory hemiplegic patients over 1 year were included as study subjects. All subjects had no previous trauma or disease history in their ankle joints and they were able to walk independently or with supervision but had spastic ankles with equinovarus tendency. We examined both ankle joints by sonography to see joint effusion and measure width, thickness, and area of tendons of the tibialis anterior, tibialis posterior, and Achilles, and also ligaments of the anterior talofibular and calcaneofibular. We compared sonographic features of the hemi-side ankle with the sound-side ankle. There were no significant differences between hemi-side and sound-side ankles in almost all measured parameters of tendons and ligaments. However, the width of the hemi-side tibialis posterior tendon (7.24±1.52 mm) was narrower than the sound-side tendon(8.61±1.37 mm). With the amount of active joint motion and weight bearing possibly preventing ligament and tendon atrophy even though marked weakness, spasticity occurred during the chronic hemiplegic phase.