• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1582-1589
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• 2006

A lock mechanism is essential for synchronization on the multiprocessor systems. The conventional queuing lock has two bus traffics that are the initial and retry of the lock-read. %is paper proposes the new locking protocol, called WPV (Waiting Processor Variable) lock mechanism, which has only one lock-read bus traffic command. The WPV mechanism accesses the shared data in the initial lock-read phase that is held in the pipelined protocol until the shared data is transferred. The nv mechanism also uses the cache state lock mechanism to reduce the locking overhead and guarantees the FIFO lock operations in the multiple lock contentions. In this paper, we also derive the analytical model of WPV lock mechanism as well as conventional memory and cache queuing lock mechanisms. The simulation results on the WPV lock mechanism show that about 50% of access time is reduced comparing with the conventional queuing lock mechanism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.331-332
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• 2022

The previously used locking device is a PIN method and has a problem in that the password is exposed by malicious users. In other words, if attackers looks at lock passwords from the side, correct passwords are known. In this paper, we aim to solve these security problems in lock devices resistant to shoulder surfing attacks. The proposed encryption approach is designed so that attackers cannot know lock passwords. To this end, we use a hidden password method instead of directly entering a PIN-type password to prevent the correct password from being exposed to an attacker even if someone steals the lock password.

• Review of KIISC
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• v.25 no.3
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• pp.66-76
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• 2015

최근 카드사 정보 유출과 더불어 유출된 개인정보를 악용한 범죄가 빈번하게 일어남에 따라 정보보호에 대한 관심과 중요성이 높아지고 있다. 국내 스마트폰 가입자 수도 4100만 명을 넘어가면서 모바일 보안에 대한 중요성 역시 강조되고 있는 가운데 지문, 홍채, 얼굴, 목소리, 눈동자 등 개개인의 고유 정보를 이용하여 인증하는 바이오 인식 기술이 주목을 받고 있다. 최근 휴대폰 제조업체들도 스마트폰 기기 내에 바이오 인식 기술을 탑재하여 기존의 인증 방식인 잠금 패턴이나 PIN 방식보다 강화된 보안성을 제공하고 있다. 또한 모바일 결제 서비스 이용 증가에 따라 바이오 인식 결제 서비스를 제공.이용할 수 있어 그 활용성은 매우 클 것으로 전망된다. 하지만 바이오 데이터의 안전한 처리 문제, 바이오 인식 서비스의 부족 등과 같은 문제점이 따르는 실정이다. 본고에서는 바이오 인식 기술의 적용 현황 및 국내외 동향을 살펴보고 바이오 인식 시장의 문제점 분석과 이에 따른 개선 방향에 대해서 연구한다.

• Journal of KIISE:Databases
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• v.27 no.4
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• pp.671-681
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• 2000

클라이언트-서버(Client-Server) 데이터베이스 환경에서 병목현상의 해결책으로 클라이언트캐시(Client cache)를 사용할 수 있다. 여러 클라이언트들이 같은 데이터베이스의 일부를 캐시한 복사본을 사용할 때, 다른 클라이언트들과 서버간에 일관성 유지를 보장해주어야 한다. 캐시의 일관성을 유지하기 위한 여러 가지 알고리즘들이 제안되어왔다. 그 중에서 O2PL(Optimistic Two Phase Locking) 기법은 동시성을 증가시킬 수 있는 주요 장점이 있다. 그러나 O2PL 알고리즘은 트랜잭션이 완료(commit) 연산을 요구하는 시점에서 접근한 캐시데이터의 일관성을 위한 작업이 시작되므로 최종적인 완료까지는 지연이 발생하게된다. 이때 다른 클라이언트에서 잠금 충돌(lock conflict)에 의해 전역 교착상태(global deadlock)가 발생한다면 블락(block)되어 지연되는 시간은 더욱 증가하게된다. 본 논문에서는 향상된 O2PL 기법으로 PN(Preemption by Notification)-O2PL 기법을 제안한다. 이 접근에서는 O2PL의 특성으로 얻을 수 있는 연산정보를 관련된 다른 트랜잭션에게 통지(notification)로 사용하고 제시한 조건에 해당할 경우 상대 자원을 바로 사용할 수 있게 한다. 이 조건은 대부분의 전역 교착 상태에 해당하는 두 트랜잭션간의 교착상태를 조기에 신속히 감지할 수 있게 하여 트랜잭션 완료의 지연을 감소시키게 한다. PN-O2PL 알고리즘이 기존의 O2PL기법보다 빠른 응답시간을 얻을 수 있음을 모의 실험을 통하여 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1B
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• pp.37-42
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• 2011

The change in performance of the mobile communication field took place due to jumping development of technology, so high performance terminals that anyone can directly search and amend desired information anywhere and anytime, namely, the mobile communication terminals called Smartphone were released to the market. The terminal can store informations that an individual stored, for example, call log, where to make contact and address of acquaintances, transmit/receive message and mail, photographs and videos, etc., but there are worries on surreptitious use of other people due to leaking of personal information through loss or theft of these terminals because of several reasons, so the present thesis aims to realize a method that remotely control information inside a terminal in case of loss of a mobile communication terminal.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.637-642
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• 2022

Self-authentication technology using electrocardiogram (ECG) signals is drawing attention as a self-authentication technology that can replace existing bio-authentication. A device that recognizes a digital electronic key can be mounted on a vehicle to wirelessly exchange data with a car, and a function that can lock or unlock a car door or start a car by using a smartphone can be controlled through a smartphone. However, smart keys are vulnerable to security, so smart keys applied with bio-authentication technology were studied to solve this problem and provide driver convenience. A personal authentication algorithm using electrocardiogram was mounted on a watch-type wearable device to authenticate bio, and when personal authentication was completed, it could function as a smart key of a car. The certification rate was 95 per cent achieved. Drivers do not need to have a smart key, and they propose a smart key as an alternative that can safely protect it from loss and hacking. Smart keys using personal authentication technology using electrocardiogram can be applied to various fields through personal authentication and will study methods that can be applied to identification devices using electrocardiogram in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.699-705
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• 2012

The role of a seat belt in a vehicle is to protect the driver from injury when a crash occurs. However when a large crash occurs, the driver slips forward and receives a strong impact. To prevent this situation, improvement of seat belts is essential. In this study, the new concept of a dynamic locking tongue (DLT) for seat belts is developed. The DLT device is used to reduce the impact to the driver's chest by tightening the webbing, so the driver is protected from severe injury in a large crash. First, a finite element model of the DLT device is created using SAMCEF and structural analysis is conducted with boundary conditions similar to those found in experiments. Then, the stress in the DLT device can be calculated. Second, the shape of the DLT device is optimized using the response surface analysis method in order to minimize the stress and weight. The validity of the optimization of the DLT device is verified using structural analysis.