델파이 기법을 활용한 품질경영시스템 조직 진단 항목개발에 관한 연구

최재웅,전병호,최재영,Choi, Jaewoong,Jun, Byoungho,Choi, Jaeyoung 디지털산업정보학회 2016 디지털산업정보학회논문지 Vol.12 No.2

The customer requirements are constantly changing in the hyper-competition and competition is becoming increasingly intensified. In order to ensure the competitive advantage in the industry should focus on the management activities to enhance customer satisfaction. High quality means pleasing customers, not just protecting them from annoyances. It is due to continuous and requires the establishment of a quality management system that meets the characteristics and systematization need to manage a stable quality and productivity, which should be done in a company-wide quality management activities. The purpose of this study is to identify a suitable organizational diagnostic model for considering to adopt ISO 9001 quality management systems. We used the three-round delphi techniques on a panel of 30 experts. A total of 26 assessment indicators were developed through this panel. First, it is important to evaluate the strategy about quality. Second, it is important to evaluate the systems about periodically communicating quality agenda. Third, it is important to evaluate the responsibility of overall business process. In conclusion, this study empirically shows how firms can develop an organizational diagnostic model to increase their quality management systems.

모델 예측 제어를 활용한 충돌 회피

최재웅,서종상,이경수,Choi, Jaewoong,Seo, Jongsang,Yi, Kyongsu 한국자동차안전학회 2013 자동차안전학회지 Vol.5 No.2

This paper presents collision avoidance using model predictive control algorithm. A model predictive control algorithm determines lateral tire force and yaw moment and steering angle input and differential braking input is determined from lateral tire force and yaw moment. A constraint for model predictive control is designed for obstacle avoidance. A objective function is designed to minimize lateral tire force and yaw moment input and to follow changed lane after collision avoidance. The performance of proposed algorithm has been investigated via computer simulation conducted to vehicle dynamic software CARSIM and Matlab/Simulink.

전방 추돌 회피를 위한 긴급 주행 보조 알고리즘 개발

최재웅(Jaewoong Choi),허현동(Hyundong Her),민석기(Sukki Min),김종갑(Jongkap Kim),이경수(Kyongsu Yi) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

긴급 주행 보조 시스템은 MDPS와 ESC를 활용하여 운전자의 충돌 회피를 보조한다. 운전자가 조향 입력을 통하여 충돌을 회피하려 할 경우, 긴급 주행 보조 알고리즘은 작동한다. 긴급 주행 보조 알고리즘은 총 4개 파트로 구성되어 있는데, 이는 각각 위험 인지, 운전자 의도 판단, 제어 전략 결정, 제어 이다. 위험 인지 단계에서는 현재 상황 위험성과 위험 영역을 도출하며, 운전자 의도 판단의 경우 운전자가 조향 입력을 통하여 충돌 회피를 하려는 것인지 판단한다. 제어 전략 결정 단계에서는 제어 동작 여부와 사용할 엑츄에이터를 결정하며, 제어 단계에서는 각 엑츄에이터의 제어량을 결정한다. 제시된 알고리즘은 차량 동역학 시뮬레이션 소프트웨어 CARSIM과 MATLAB/SIMULINK를 활용하여 시뮬레이션하였다. Emergency driving support (EDS) algorithm supports the driver to avoid collision using motor driven power steering (MDPS) and electronic stability control (ESC). If driver try to avoid rear-end collision using steering input, the EDS system activated and support the driver. The EDS algorithm consists of 4 parts: risk monitoring, driver monitoring, decision and control. In risk monitoring process, inverse time-to-collision is used for risk monitoring and danger area is estimated. In driver monitoring process, driver’s intention in emergency situation is estimated. In decision process, the control policies are determined. Finally, in control process, the control inputs of actuators are determined. The performance of proposed algorithm has been investigated via computer simulation conducted to vehicle dynamic software CARSIM and Matlab/Simulink.

Identifying Interdisciplinary Trends of Humanities, Sociology, Science and Technology Research in Korea Using Topic Modeling and Network Analysis

최재웅(Jaewoong Choi),장재혁(Jaehyuk Jang),․,김대환(Dae Hwan Kim),․,윤장혁(Janghyeok Yoon) 한국산업경영시스템학회 2019 한국산업경영시스템학회지 Vol.42 No.1

As many existing research fields are matured academically, researchers have encountered numbers of academic, social and other problems that cannot be addressed by internal knowledge and methodologies of existing disciplines. Earlier, pioneers of esearchers thus are following a new paradigm that breaks the boundaries between the prior disciplines, fuses them and seeks new approaches. Moreover, developed countries including Korea are actively supporting and fostering the convergence research at the national level. Nevertheless, there is insufficient research to analyze convergence trends in national R&D support projects and what kind of content the projects mainly deal with. This study, therefore, collected and preprocessed the research proposal data of National Research Foundation of Korea, transforming the proposal documents to term-frequency matrices. Based on the matrices, this study derived detailed research topics through Latent Dirichlet Allocation, a kind of topic modeling algorithm. Next, this study identified the research topics each proposal mainly deals with, visualized the convergence relationships, and quantitatively analyze them. Specifically, this study analyzed the centralities of the detailed research topics to derive clues about he convergence of the near future, in addition to visualizing the convergence relationship and analyzing time-varying number of research proposals per each topic. The results of this study can provide specific insights on the research direction to researchers and monitor domestic convergence R&D trends by year.

서버 클러스터에서의 인터넷 서비스를 위한 효율적인 연결 스케줄링 기법 (pp.352-358)

최재웅(Jaewoong Choi),김성천(Sungchun Kim) 한국정보과학회 2003 정보과학회논문지 : 시스템 및 이론 Vol.30 No.7·8

LAN 환경의 웹 서버 클러스터 구조가 각광을 받고 있다. 높은 가용성 및 확장성을 보장하는 웹 서비스를 제공하기 위해 많은 부하의 서비스 요구를 여러 서버에게 효과적으로 나누어 처리할 수 있는 합리적인 스케줄링 기법을 필요로 한다. ONE-IP 스케줄링 기법은 이더넷의 브로드캐스트 메시지에 의해 스케줄링이 분산되도록 하는 전략을 사용한다. 이 기법은 클러스터에 유입되는 패킷의 집중화로 인해 발생할 수 있는 병목 현상(bottleneck)과 치명적인 오류(Single-point of Failure) 문제를 효과적으로 해결하였으나, 단순한 패킷 스케줄링을 사용하기 때문에 클러스터를 구성하는 서버들 간의 부하 불균형을 가중시키며, 결과적으로 클러스터의 효율성을 저하시키는 문제점을 가지고 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 RR ONE-IP 기법을 제안하였다. 제안한 기법은 서버에 할당되는 부하간에 불균형이 발생하는 문제점을 해결하기 위해 TCP 연결 단위의 스케줄링 전략을 사용하였으며, RR 스케줄링 기법을 도입함으로써, ONE-IP 기법의 장점을 그대로 유지하면서 보다 나은 부하의 균등한 분배로 시스템의 처리 능력을 향상시키도록 하였다. 또한, 실험을 수행한 결과 제안한 기법이 기존의 기법에 비해 평균 3.84%의 시스템의 성능 향상을 보였으며, 과부하 발생율에서는 평균 23.5%의 감소를 가져왔음을 보였다. A cluster of servers is the most promising solution to provide highly scalable and highly available network services with low implementation cost. One of popular solutions is using dispatcher as a request distributor. However this solution has the problem that it can be the bottleneck or single-point of failure point of itself. ONE-IP, the previous work, solves this serious problem by using broadcast message for distributing the request packet in LAN. Using simple scheduling technique, in addition, the overhead due to dispatching the request becomes minimal. However, as ONE-IP using very simple static scheduling algorithm, it would spread the requests among servers unevenly and downgrades the cluster performance consequently. In this paper, we propose an improved TCP connection scheduling technique solving this unbalanced distributing problem. Using Round-Robin(RR) scheduling instead of hashing clients IP address, proposed technique can more evenly distribute incoming service requests among the servers. Experiments show average 3.8% improved performance in throughput compared to original ONE-IP technique.

머플러 케이스의 최적재료 선정

최재웅(Jaewoong Choi) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The durability of material for automotive exhaust system mainly depends on the partial corrosion of muffler caused by condensed water on the inside and chloride scale on the outside of muffler case. Accordingly, Al-coated steel sheet were generally used in the past. However, ferritic stainless steel (SUS409L. 439L. 436L) are mostly used to increase the expected life span of muffler in these days. But, lor cost reduction and customer satisfaction, we developed the lab scale test methods which could reproduce the field pans and selected materials for automotive exhaust system on the based of its results because it's been brought to our attention that need tor optimization of the material selection based on the driving region and vehicle type by grade.

객체 분할 정보를 활용한 선화 생성 모델의 성능 개선

최재웅(JaeWoong Choi),하정민(JungMin Ha),이혜진(Hyejin Lee),이재구(Jaekoo Lee) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2

11wt% Cr 페라이트계 스테인리스강의 자동차 웅축수 내에서의 부식 거동에 관한 연구

최재웅(Jaewoong Choi) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Surface corrosion behavior of 11wt % Cr terrific stainless steel was investigated in the automobile condensate using XRD and XPS. Compositions of automobile condensate was analyzed by ion chromatography. Immersion test was carried out at 366k for 480h in the 95% concentrated condensate and thin oxide layer was formed on the surface after the test. As immersion time and temperature goes by, the oxide layer thickness, pitting depth and width increased. The oxide layer compound was investigated by XPX analysis. Before immersion test, the Cr peak was strong, Si was not oxidized. But after the test, Cr peak became weak, Si peak changed to be Si oxide after tile test. Fe oxidized easily in the condensate and formed Fe₂O₃, Fe₃O₄Fe oxide was the major surface components after immersion test.

자율주행을 위한 쟁애물 검지 알고리듬 개발

최재웅(Jaewoong Choi),김동욱(Dongwook Kim),이경수(Kyongsu Yi) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

This paper presents an obstacle detection algorithm for autonomous driving. The obstacle detection algorithm has been designed, consisting 3 parts, detected points organization, classification and obstacle map generation algorithm. Detected points organization algorithm processes LIDAR output as a point cloud of vehicle coordinate. Classification algorithm separates the detected points to ground and obstacle by derivation of detected points. Obstacle map generation algorithm derives the obstacle map by classified points. The designed algorithms have been implemented on test vehicle which has 6 LIDARs, 3 cameras and RT devices including PCs and tested in real-time.

컴파운드 하이브리드 굴삭기의 통합 제어 기술 개발

최재웅(Jaewoong Choi),김학구(Hakgu Kim),이경수(Kyoungsu Yi),유승진(Seungjin Yoo) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

This paper presents an integrated control algorithm for a compound hybrid excavator. The excavator models which consist of engine, pump and electric components are developed to evaluate the conventional and compound hybrid excavator’s fuel consumption. Two different integrated control algorithms are proposed. The considered approaches are: low power charge rule-based control and low power assist rule-based control. To verify the proposed control algorithm, simulation is accomplished with MATLAB/SIMULINK and the simulation results show that low power charge rule-based control is better than low power assist rule-based control. The fuel consumption of the compound hybrid excavator can be reduced about 25% of fuel compared to the conventional hydraulic excavator.