• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.903-908
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• 2007

A retractor is the major component of a seatbelt system that restraints passengers by locking the movement of webbing. Recently, in order to increase the effectiveness of seatbelt systems, motorized retractors that remove slack and correct passenger posture just before airbag expansion when collision is predicted are widely used. Key component of motorized retractors is the one-way clutch that engages and disengages the winding action of webbing according to the direction of motor revolution. Analytical investigation of action of the one-way clutch mechanism has been carried out to figure out conditions for one-way locking, and to study the effect of various kinematic and dynamic design variables of one-way clutch. Using combination of ADAMS and LifeMOD soft-wares, dynamic simulation of operation of motorized retractors including Hybrid-III dummy model has been carried out to evaluate the performance of the motorized retractors in various crash scenarios.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1195-1200
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• 2007

It is desirable that the guard robot should be small-sized and light-weighted to increase its portability. In addition, it should be able to overcome a relatively high obstacle to cope with different situations. The jumping robot can reach a higher place more rapidly than other locomotion methods. This research proposes the jumping mechanism based on the conical spring for a small robot. Both the clutch mechanism and conical spring are incorporated into the jumping mechanism. In the clutch mechanism, the spring can be immediately compressed and released by one actuator with the planetary gear train and one-way clutch. The robot equipped with the jumping mechanism can overcome the obstacles which are higher than its height. In this paper, the characteristic of the conical spring for the jumping robot is determined and the small-sized, lightweight jumping mechanism is developed. The validity of the jumping mechanism was verified by various experiments. It is shown that the robot using this mechanism can provide good mobility in the rough terrain.

• 정보통신설비학회논문지
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• 제10권2호
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• pp.74-79
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• 2011

The goal of this research is to reduce dynamic and static power consumption for a low power cache system. The proposed cache can achieve a low power consumption by using a drowsy and a way prediction mechanism. For reducing the static power, the drowsy technique is used at 4-way set associative cache. And for reducing the dynamic energy, one among four ways is selectively accessed on the basis of information in the Way-Line Prediction Unit (WLPU). This prediction mechanism does not introduce any additional delay though prediction misses are occurred. The WLPU can effectively reduce the performance overhead of the conventional drowsy caching by waking only a drowsy cache line and one way in advance. Our results show that the proposed cache can reduce the power consumption by about 40% compared with the 4-way drowsy cache.

• 정보보호학회논문지
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• 제26권3호
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• pp.613-621
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• 2016

데이터가 일방향으로 전송되는 네트워크 환경에서 데이터에 대한 오류 제어는 매우 민감하고 중요한 문제이다. 이 문제를 해결하기 위해서 전방향 오류 정정 부호 기법이나 수신 결과를 회신하여 데이터를 재전송하는 기법이 사용되고 있다. 본 논문에서는 데이터를 일방향으로 전송하는 채널과 수신 결과만 회신할 수 있는 별도의 채널이 있는 네트워크 환경에서 오류 제어 기법 및 연속 데이터 전송을 할 수 있는 프로토콜을 제안한다. 또한, 일방향 네트워크에서 사전 공유 키 분배 기법에 기반한 데이터 암호 및 키 업데이트 메커니즘을 제안하고 이를 구현하기 위한 응용 서비스 데이터 단위(ASDU) 구조를 제시한다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2007년도 춘계학술발표대회
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• pp.1100-1101
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• 2007

This paper proposes an efficient mechanism of node membership verification within the groups of sensors in a wireless sensor network (WSN). We utilize one-way accumulator to check the memberships of the legitimate nodes in a secure way. Our scheme also supports the addition and deletion of nodes in the groups in the network. Our analysis shows that, our scheme could be well-suited for the resource constrained sensors in a sensor network and it provides a lightweight mechanism for secure node membership verification in WSN.

• 산업기술연구
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• 제26권A호
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• pp.55-61
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• 2006

Motorized retractors enhance the safety of passengers by removing the slack of webbing and by holding upright driving position. Reliability of a driving mechanism that includes one-way clutch between the driving motor and webbing is directly linked to the safety of passenger. In this research, conditions for locking one-way clutch, and also conditions for sustaining locking are theoretically investigated. The operation of a motorized retractor under realistic conditions is simulated in order to validate the proposed retractor design.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3131-3149
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• 2016

In-band Full-duplex (IBFD) wireless communication allows improved throughput for wireless networks. The current Half-duplex (HD) medium access mechanism Request to Send/Clear to Send (RTS/CTS) has been directly applied to IBFD wireless networks. However, this is only able to support a symmetric dual link, and does not provide the full advantages of IBFD. To increase network throughput in a superior way to the HD mechanism, a novel three-way handshaking access mechanism RTS/SRTS (Second Request to Send)/CTS is proposed for point to multipoint (PMP) IBFD wireless networks, which can support both symmetric dual link and asymmetric dual link communication. In this approach, IBFD wireless communication only requires one channel access for two-way simultaneous packet transmissions. We first describe the RTS/SRTS/CTS mechanism and the symmetric/asymmetric dual link transmission procedure and then provide a theoretical analysis of network throughput and delay using a Markov model. Using simulations, we demonstrate that the RTS/SRTS/CTS access mechanism shows improved performance relative to that of the RTS/CTS HD access mechanism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.131-146
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• 2012

As one of the four basic technologies of IOT (Internet of Things), M2M technology whose advance could influence on the technology of Internet of Things has a rapid development. Mobile Payment is one of the most widespread applications in M2M. Due to applying wireless network in Mobile Payment, the security issues based on wireless network have to be solved. The technologies applied in solutions generally include two sorts, encryption mechanism and authentication mechanism, the focus in this paper is the authentication mechanism of Mobile Payment. In this paper, we consider that there are four vital things in the authentication mechanism of Mobile Payment: two-way authentication, re-authentication, roaming authentication and inside authentication. Two-way authentication is to make the mobile device and the center system trust each other, and two-way authentication is the foundation of the other three. Re-authentication is to re-establish the active communication after the mobile subscriber changes his point of attachment to the network. Inside authentication is to prevent the attacker from obtaining the privacy via attacking the mobile device if the attacker captures the mobile device. Roaming authentication is to prove the mobile subscriber's legitimate identity to the foreign agency when he roams into a foreign place, and roaming authentication can be regarded as the integration of the above three. After making a simulation of our proposed authentication mechanism and analyzing the existed schemes, we summarize that the authentication mechanism based on the mentioned above in this paper and the encryption mechanism establish the integrate security framework of Mobile Payment together. This makes the parties of Mobile Payment apply the services which Mobile Payment provides credibly.

• 정보보호학회논문지
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• 제9권2호
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• pp.25-36
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• 1999

이 논문에서는 S/KEY 메커니즘에서 사용 횟수 제한과 사전에 키를 만들어 저장해야 하는 중요한 문제점을 해결한 일회용 패스워드 메커니즘을 제안하다. 제안한 일회용 패스워드로부터 인증용키를 생성함으로써 인증용 키관리를 용이하게 하고, 인증과 더불어 클라이언트와 서버간의 통신 세션키의 분배도 가능하게 한다. 그리고 제안한 메커니즘은 스마트 카드를 이용함으로 인증 정보의 보호 및 관리가 용이하며, 서버의 challenge가 없는 클라이언트에서 서버로의 단방향 인증을 필요로 하는 시스템에 바로 적용된다. In this paper we propose a one-time password mechanism that solves the problems of the S/KEY: the limitation of a usage and the need of storage for keys. because of using a cryptographic algorithm the proposed mechanism has no the limitation of a usage. Also because of producing the key for an authentication from a user's password it is easy to manage the authentication key and is possible to share the session key between a client and a server after the authentication process. In addition the proposed mechanism is easy to protect and manage the authentication information because of using a smart card and is adopted by the system that needs a noe-way authentication from a client to a server without the challenge of a server.

• 한국생산제조학회지
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• 제18권5호
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• pp.462-468
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• 2009

In this study, a workpiece-chucking device that generates a chucking force from a shape memory alloy is introduced. This paper first presents train procedure to transform a commercial one-way shape memory alloy into a two-way shape memory alloy, which makes unclamping mechanism of the chucking device simpler than that using the one-way shape memory alloy Second, it describes a conceptual design of the workpiece-chucking device using the two-way type shape memory alloy. Third, it presents a prototype and its chucking characteristics, such as time-response of clamping/unclamping operations and a relationship between temperatures and chucking forces. Finally, it describes a mill-machining test conducted with the prototype. The results confirm that the proposed workpiece-chucking device is feasible for micro machine-tools.