• 한국기계가공학회지
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• 제19권5호
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• pp.1-7
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• 2020

This study examines the processing and performance of an f-theta lens, one of the main components used in laser printer and laser scanning systems. To design an f-theta lens, the optical path of the components of the laser scanning unit f-theta lens, cylinder lens, and collimator lens must be identified. The goal after machining the master f-theta lens is to understand the optical properties, root mean square, and peak to valley.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.38-40
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• 2007

In this paper, we propose a novel architecture, which is based on DCT (Discrete Cosine Transform), for ME (Motion Estimation) and MC (Motion Compensation). The traditional algorithms of ME and MC based on DCT did not suffer the advantage of the coarseness of the 2-dimensional DCT (2-D DCT) coefficients to reduce the operational time. Therefore, we derive a recursion equation for transform-domain ME and MC and design the structure by using highly regular, parallel, and pipeline processing elements. The main difference with others is removing the IDCT block by using to transform domain. Therefore, the performance of our algorithm is more efficient in practical image processing such as DVR (Digital Video Recorder) system. We present the simulation result which is compare with the spatial domain methods. it shows reducing the calculation cost. compression ratio. and peak signal to noise ratio (PSNR).

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1073-1081
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• 2000

This paper proposes a new fault-tolerant technique for bitonic sorting networks which can be used for designing ATM switches based on Batcher-Banyan network. The main goal in this paper is to design a cost-effective fault-tolerant bitonic sorting network. In order to recover a fault, additional comparison elements and additional links are used. A Dynamic Redundant Bitonic Sorting (DRBS) network is based on the Dynamic Redundant network and can be constructed with several different variations. The proposed fault-tolerant sorting network offers high fault-tolerance; low time delays; maintenance of cell sequence; simple routing; and regularity and modularity.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2005년도 추계학술발표대회 및 정기총회
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• pp.7-10
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• 2005

최근 인터넷을 중심으로 한 첨단 기술 산업이 발달함에 따라 고성능 트랜잭션 처리가 요구되고, XML 관련 기술들 역시 확대 적용되고 있다. 이에 따라 디스크 기반 DBMS 의 한계를 극복하고, 점차 사용 범위가 확대되고 있는 XML 기술을 지원하기 위한 시스템의 필요성이 대두되고 있다. 기존의 XML 저장 방법은 대부분 XML DOM 구조 정보만을 저장하는 것이었으나, 이 방법은 XQuery를 처리하는 속도면에 한계가 있었다. 본 논문에서는 이 점을 해결하기 위해 2 중의 인덱스 구조를 두어, XQuery 처리 속도를 향상시킬 수 있는 주기억 상주형 XML DBMS 의 저장 구조를 설계 한다.

• 한국분말재료학회지
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• 제27권5호
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• pp.420-428
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• 2020

Additive manufacturing technology is recognized as an optimal technology for mass-customized distributed production because it can yield products with high design freedom by applying an automated production system. However, the introduction of novel technologies to the additive manufacturing industry is generally delayed, and technology uncertainty has been pointed out as one of the main causes. This paper presents the results of the research and analysis of current standardization trends that are related to additive manufacturing by examining the hierarchical structure of the quality system along with the various industry and evaluation standards. Consequently, it was confirmed that the currently unfolding standardization does not sufficiently reflect the characteristics of additive manufacturing technology, and rather can become a barrier to entry for market participants or an element that suppresses the lateral shearing ability of additive manufacturing technology.

• 한국표면공학회지
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• 제30권5호
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• pp.298-309
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• 1997

Hard Tin coating on tool steel substrate were prepared using the pulsed PACVE. An orthogonal experimental design was employed to find the best deposition conditions for TiN coating and to systematically understand the effect of processing parameters. The small size Taguchi matrix called the L16 was used for experiment and ANOVA(ANalysis of VAriance) was followed to study the effect of main parameters on hardness and adhesion TiN coatings. In conclusion, pulse on/off time ratio and pulsing frequency were the major deposition parameters to determine hardness and adhesion of TiN coating in the pulsed DC PACVE process. (200) preferred orientation, columnar growth and dome-shaped surface morphology of the TiN films gave rise to a high hardness and a good adhesion to the substrates.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.1763-1764
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• 2015

사이버나이프 시스템은 독특한 형태의 정위적 방사선 치료를 수행하는 로봇 팔을 이용하는 방사선 수술 시스템으로 치료 중 환자의 호흡 등에 따른 신체의 움직임에도 1mm 이내의 오차 범위에서 정확하게 방사선을 조사해야하며, 여러 병소를 동시에 치료할 수 있다. 사이버나이프 시스템은 로봇 팔, 선형 가속기, 병소 위치 추적 장치, 방사선 조사 스케줄러와 같은 다양한 모듈들이 통합된 시스템으로, 이를 통합 제어하기 위한 주제어 시스템이 필요하다. 본 논문에서는 본 연구원에서 개발하고자 하는 사이버나이프 주제어 시스템의 설계에 관하여 기술한다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.785-788
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• 2012

There has been growing interest in multicast technologies for wireless mesh networks with increasing demand for enjoying seamless multimedia broadcast service such as mobile IPTV anytime anywhere for any content on any device. This paper addressed the factors that should be considered when designing multicast algorithm in WMNs. Several routing metrics which are adapted for WMNs based multicast are described in detail to show that the main design goal for multicast metric is to achieve high throughput. Those metrics that take into account the characteristics of WMNs such as wireless broadcast advantage or channel diversity can arrange load balancing more effectively.

• 한국정보과학회논문지:데이타베이스
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• 제33권7호
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• pp.668-681
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• 2006

XML은 다양한 장점으로 인해 인터넷 기반 환경에서 데이타 표현 및 교환의 표준으로 자리잡았다. XML이 데이타 표현 및 교환의 주요한 포맷으로 자리잡으면서 XML 데이타의 효율적인 저장 및 질의 처리에 대한 연구가 활발히 진행되었다. XML 데이타를 관계형 데이타 베이스시스템에 저장하는 것은 데이타 관리와 질의 처리에서 많은 이익을 가져온다. 왜냐하면, 관계형 데이타 베이스 시스템은 강력한 질의 처리 및 데이타 관리 기능을 제공하고, 이들 기능을 확장하여 XML 데이타에 적용할 수 있기 때문이다. 그러나, 이 방법을 사용하기 위해서는 XML 질의를 SQL 질의로 변환해야 한다. 본 논문에서는 대표적인 XML 질의 언어인 XQuery 질의를 SQL:2003 질의로 변환하는 질의 번역기를 설계 및 구현한다. SQL:2003은 SQL:1999을 대체하는 최신 SQL 표준으로, XML을 지원하기 위한 SQL/XML을 정의하고 있다. 본 논문의 주요 공헌은 다음과 같다. 첫째, SQL:2003 표준에서 정의하고 있는 XML 지원 특징을 살펴보고 미흡한 부분에 대한 사용자 정의 함수를 제안한다. 둘째, XQuery 질의를 SQL:2003 표준을 준수하는 SQL 질의로 변환하는 방법을 제안한다. 셋째, 번역기에 대한 설계와 구현을 자세히 기술하여 번역기의 가능성(feasibility)을 보여준다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권2호
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• pp.136-144
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• 2014

The existing conventional motion controller does not perform well in the presence of nonlinear properties, uncertain factors, and servo lag phenomena of industrial actuators. Hence, a feasible and effective fuzzy self-tuning proportional integral derivative (PID) and feed-forward control scheme is introduced to overcome these problems. In this design, a fuzzy tuner is used to tune the PID parameters resulting in the rejection of the disturbance, which achieves better performance. Then, both velocity and acceleration feed-forward units are added to considerably reduce the tracking error due to servo lag. To verify the capability and effectiveness of the proposed control scheme, the hardware configuration includes digital signal processing (DSP) which plays the main role, dual-port RAM (DPRAM) to guarantee rapid and reliable communication with the host, field-programmable gate array (FPGA) to handle the task of the address decoder and receive the feed-back encoder signal, and several peripheral logic circuits. The results from the experiments show that the proposed motion controller has a smooth profile, with high tracking precision and real-time performance, which are applicable in various manufacturing fields.