• Journal of the Semiconductor & Display Technology
• /
• v.7 no.2
• /
• pp.39-43
• /
• 2008

Productivity is one of the performance indices of the semiconductor equipment in manufacturing viewpoint. Among many ways tried and adopted for improvement of the productivity of the FAB equipment, variation of equipment configuration was considered and its effect on the throughput was analyzed. Parallel machine cycle charts that were generated based on the equipment log were used in the analysis. Efficiency of the equipment due to change of the structure and the probability of the usage in the manufacturing process were examined. The results showed that the modification of the control algorithm in the equipment and the redistribution of the process time for each process and transfer module along to the change in the structure enhance the throughput of the equipment.

• Journal of the Korean Society for Railway
• /
• v.5 no.2
• /
• pp.104-111
• /
• 2002

The purpose of interlocking system was to prevent the route for a train being set up and its protecting signal cleared if there was already another, conflicting route set up and the protecting signal for that route cleared. This paper proposed Interlocking Inspection System(IIS) consisting of interlocking simulator and field simulator to operate interlocking test of computer based Electronic Interlocking System(EIS) in this paper. Interlocking simulator consists of Design Edit System(DES), Logical Database Management Tool(LDMT) and real-time confirming system, field simulator is a equipment to simulate a control object of EIS and constitutes configuration operated in 19 inch standard rack. As a result of test to prove capacity of this IIS, the efficiency was shown as excellent. Therefore by using inspection system, we obtain every advantages. It has the functions for test data generation and automatic test execution based on personal computer. Time and cost for test work can be reduced more efficiently by using this developed inspection system

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.45 no.4
• /
• pp.530-534
• /
• 1996

A novel phase error predictor is proposed for servo system in home-use VCRs. The multirate system in VCRs is converted into a single period sampling system with faster sampling time by using the proposed novel phase error predictor. And the disturbances can be measured much faster. From the experimental results, we can see that the perfomance of the control system is improved greatly. The phase lock time of the proposed servo system is ten times faster than that of the conventional system.

• Journal of information and communication convergence engineering
• /
• v.3 no.1
• /
• pp.18-22
• /
• 2005

This paper presents the analog adaptive phase-locked loop (PLL) architecture with a new adaptive bandwidth controller to reduce locking time and minimize jitter in PLL output for wireless communication. It adaptively controls the loop bandwidth according to the locking status. When the phase error is large, the PLL increases the loop bandwidth and reduces locking time. When the phase error is small, the PLL decreases the loop bandwidth and minimizes output jitters. The adaptive bandwidth control is implemented by controlling charge pump current depending on the locking status. A 1.28-GHz CMOS phase-locked loop with adaptive bandwidth control is designed with 0.35 $mu$m CMOS technology. It is simulated by HSPICE and achieves the primary reference sidebands at the output of the VCO are approximately -80dBc.

• Proceedings of the KIEE Conference
• /
• 1995.07a
• /
• pp.258-260
• /
• 1995

A novel phase error predictor is proposed for servo system in home-use VCRs. The multirate system in VCRs is converted into a single period sampling system with faster sampling time by using the proposed novel phase error predictor. And the disturbances can be measured much faster. From the experimental results, we can see that the performance of the control system is improved greatly. The phase lock time of the proposed servo system is ten times faster than that of the conventional system.

• International Journal of Internet, Broadcasting and Communication
• /
• v.13 no.3
• /
• pp.1-11
• /
• 2021

Development of ICT technologies leads exponential growth of various sharing economy over the last couple of years. The intuitive advantage of the sharing economy is efficient utilization of idle goods and services, but there are safety and security concerns. In this paper, we propose a onetime password based access control system to support secure accommodation sharing service and show the implementation results. To provide a secure service to both the provider and the user, the proposed system issues a onetime access password that is valid only during the sharing period reserved by the user, thereafter access returns to the accommodation owner. Especially, our system provides secure user access by merging the two elements of speaker recognition using voice and a one-time password to open and close the door lock. In this paper, we propose a secure system for accommodation sharing services as a use-case, but the proposed system can be applicable to various sharing services utilizing security-sensitive facilities.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2020.11a
• /
• pp.16-19
• /
• 2020

사회에서 다양한 디지털 도어락 관련 범죄들이 꾸준히 늘어나면서 소비자들은 보안성이 강화된 도어락을 요구하고 있다. 이에 따라 도어락 시장도 보안성을 강화한 스마트 도어락을 개발하는 데 집중하고 있다. 본 연구에서는 사람이 보안을 위해 사용하는 OTP(One-Time-Password) 라는 검증된 암호시스템을 사용하여 비밀번호의 노출, 비밀번호의 분실의 위험이 없는 보안성과 편의성을 강화한 OTP 스마트 도어락 모듈을 구현하였다.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.11
• /
• pp.2751-2762
• /
• 1998

In this paper, a new priority assignment ploicy and concurrency control for improvement of transaction predictability and performance are proposed. We present a new priority assignment algorithm called classified priority assignment(CPA), which solves the defects of Earliest Deadline First(EDF) by using class and bucket, and deals with real-time transaction and time-sharing transaction effectively. Also, we present a new concurrency control policy called conditional optimistic concurrency control using lock. It uses optimistic concurrency control for improvement of predictability, and solves transaction conflict by considering priority and execution time of transaction to waste less system resource.

• Journal of KIISE:Software and Applications
• /
• v.26 no.9
• /
• pp.1073-1084
• /
• 1999

이동 컴퓨팅 환경에서 이동 호스트는 제한된 대역폭을 효율적으로 사용하고 이동 트랜잭션의 응답 시간을 향상시키기 위하여 캐쉬를 이용한다. 그리고 이동 호스트에 캐슁된 데이타가 이동 지구국에서 갱신되면 이동 호스트의 캐쉬 일관성을 유지하기 위하여 이동 지구국은 무효화 메시지를 방송한다. 그러나 이동 지구국에서 주기적으로 무효화 메시지를 방송하는 방법은 이동 트랜잭션의 빠른 처리를 위하여 이동 지구국으로부터 데이타를 즉시 캐슁하는 경우에 이동 트랜잭션의 직렬가능한 수행을 보장할 수 없는 경우가 발생한다. 본 연구에서는 캐슁된 데이타를 이용하여 이동 트랜잭션을 수행하는 경우에 록을 이용하여 이동 트랜잭션의 직렬가능한 수행을 보장하는 UCL-MT 방법과 록 관리 방법을 제안한다. 제안하는 UCL-MT 방법은 이동 트랜잭션을 완료하기 이전에 이동 트랜잭션이 접근한 데이타 정보를 이용하여 지구국에서 사이클을 탐지함으로써 이동 트랜잭션의 직렬가능한 수행을 보장한다. 또한 제안하는 록 관리 방법은 이용할 수 있는 대역폭의 크기에 따른 무효화 메시지 내용의 변화에 유연하게 적용될 수 있다. Abstract In mobile computing environments, a mobile host caches the data to use the narrow bandwidth efficiently and improve the response time of a mobile transaction. If the cached data in mobile host is updated at a mobile support station, the mobile support station broadcasts an invalidation message for maintaining the cache consistency of a mobile host. But when a mobile transaction accesses the data which is not in cache, if a mobile host caches the data immediately from a mobile support station for processing a mobile transaction rapidly, the method that a mobile support station broadcasts an invalidation message periodically, happens to the case that can not guarantee the serializable execution of a mobile transaction. In this paper, we propose the UCL-MT method and lock management method, as a mobile transaction is executed using cached data. Since, using the data a mobile transaction accessed, the UCL-MT method detects a cycle in a mobile support station before the completion of the mobile transaction, it guarantees the serializable execution of the mobile transaction. Also, proposing lock management method can be adapted flexibly at the change of invalidation message content, according to the available bandwidth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.255-256
• /
• 2006

In this paper, we investigated the. characteristics of fault current limiting according to fault angle in the integrated three-phase flux-lock type SFCL in fault types such as the single-line-to-ground fault, the double-line-to-ground fault and the three-line-to-ground fault. When the SFCL is operating under normal condition, the magnetic flux generated between primary and secondary coils of each single phase is canceled out perfectly, so that the impedance of the SFCL is also not generated and the power system can be operated normally without any loss, However, if a fault occurs even in any phase out of three phases, quench happened in SFCL elements and the current flowing secondary coil is restricted abruptly. Finally, the balance of magnetic flux in whole SFCL system is destroyed, and the fault currents in every phase could be limited at the same time irrespective of the fault types. As a result, the developed SFCL in this study were operated normally as expected and the purpose of the integration of 3 phase current limiting was also achieved successfully. However, the fault current limiting characteristics of the SFCL was dependant on the quench characteristics of HTSC elements in each phase, and it was expected that the improvement of the SFCL could be possible through the introduction of HTSC elements which have better critical characteristics.