• Journal of Internet Computing and Services
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• 제19권6호
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• pp.31-40
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• 2018

With the development of IT technology recently, medical information systems are being constructed in an integrated u-health environment through cloud services, IoT technologies, and mobile applications. These kinds of medical information systems should provide the medical staff with authorities to access patients' medical information for emergency status treatments or therapeutic purposes. Therefore, in the medical information systems, the reliable and prompt authentication processes are necessary to access the biometric information and the medical information of the patients in charge of the medical staff. However, medical information systems are accessing with simple and static user authentication mechanism using only medical ID / PWD in the present system environment. For this reason, in this paper, we suggest a dynamic situation authentication mechanism that provides transparency of medical information access including various authentication factors considering patient's emergency status condition and dynamic situation authentication system supporting it. Our dynamic Situation Authentication is a combination of user authentication and mobile device authentication, which includes various authentication factor attributes such as emergency status, role of medical staff, their working hours, and their working positions and so forth. We designed and implemented a dynamic situation authentication system including emergency status decision, dynamic situation authentication, and authentication support DB construction. Finally, in order to verify the serviceability of the suggested dynamic situation authentication system, the medical staffs download the mobile application from the medical information server to the medical staff's own mobile device together with the dynamic situation authentication process and the permission to access medical information to the patient and showed access to medical information.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.159-163
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• 2003

In recent days, as the efficiency of electronic home applications become higher, that of the driving AC motor become higher. On this reason, the demand fir high capacity coil firming machine is increasing. Since the coil forming is not simply related with the only capacity of hydraulic cylinder, the development of a newer coil firming machine which has new filming mechanism new driving method, new filming tool, and new specification is required. In this paper, the virtual prototype which have new mechanism is developed. This prototype is tested and experimented on PC with the same condition as actual. The results from the virtual experiment is applied to the actual design process.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제8권1호
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• pp.33-40
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• 2007

RFID, a non-contact wireless identification technology is being noticed as a technology to alternate barcode system in distribution industry and general industry. Despite of merit of RFID, there are issues to be solved for practical use. One of them, which are most important, is resolution of user's information protection. RFID system without security function bears risk exposing personal data and user's privacy. In this paper, we propose mutual authentication protocol for RFID system in order to solve this security issue. This study aimed to protect user's privacy by providing dynamic ID for tag through authentication protocol safe from security threats. Information being transmitted between backend, reader and tag has no direct connection with ID of tag, and it conducts authentication process using one-way hash function, which prevents attacker's obtaining of tag information using information being transmitted.

• The Journal of Society for e-Business Studies
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• 제17권1호
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• pp.137-150
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• 2012

For social demand and technological development, systematic private information management and security guidance have been enhanced; however, the issue of leakage and invasion of private information is shown in many ways. In the management of such private information, the issue of how to protect such information is one of the sensitive key elements. As a criterion to decide the management policy of each property information consisting of private information, this article suggests Dynamic-Security-Level-Measurement for property information. DSLM adopts the variable characteristics of property information as the element of measurement. By applying this method, it is possible to provide information management functions to cope with the changes of each property information security level of an individual actively. It is expected that this will improve the security of previous information management methods even more and also contribute to the improvement of security in integrated systems such as the integrated ID management system and electronic wallet.

• Transactions of the Korean Society of Automotive Engineers
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• 제8권3호
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• pp.85-97
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• 2000

In this paper, static and dynamic shift control stategies of CVT speed ratio are suggested. For the static shift control, in order to operate engine on the optimal operating region, a fuzzy control logic is used. In the fuzzy logic, S- factor that is defined as a degree of sportiness is introduced. Simulation results show that the static shift control strategy based on the fuzzy logic selects the optimal operating point automatically between the economy and the sporty mode corresponding to the driver's desire and the driving condition. For the dynamic shift control strategy, a shift speed map is suggested which determines the shift sped as fast or slow based on Δi, the difference between the desired speed ratio id and the actual speed ratio i, and throttle opening. It is seen from the simulation results that the CVT shift speed is determined by the dynamic shift control strategy to provide appropriate performance and comfort for the driver's demand and driving condition. Additionally, experiments are performed to investigate the dynamic performance of the shift speed for the lift foot up. From the experimental results, it is found that improved shift feeling can be obtained by the dynamic shift control strategy when lift foot up occurs.

• Proceedings of the Korean Information Science Society Conference
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• 한국정보과학회 1998년도 가을 학술발표논문집 Vol.25 No.2 (3)
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• pp.249-251
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• 1998

본 논문은 개인 휴대통신망네에서의 각 노드간 시그날링 트래픽을 감소시키기 위한 기법에 관한 연구이다. 미래의 개인휴대통신망에서는 셀 크기가 더욱 작이지고 사용자가 증가혀 현 개인휴대통신의 문제점인 HLR로의 시그날 병목현상. 인접지역에서의 핑퐁효과 발생이 더욱 심화돌 것이다. 본 논문에서는 이와 같은 문제의 해결을 위해 각 VLR들이 자신을 중심으로 일정한 Circle Registration area를 가지면 이 area내의 VLR 들의 id를 가지는 DCLR(Dynamic Circle Location Register)이 되도록 한다. 단말이 다른 지역으로이동할 때 마다 단말이 현 DCLR area에 있는지를 검사후 해당 DCLR 로 단말의 최신 위치정보를 연속적으로 전송하고, 또한 이러한 이동에 따라 동적으로 단말의 DCLR이 변화되며, 호 발생시는 단말의 해당 DCLR을 조회함으로써 수신자의 위치를 추적한다. 이 방식은 기존 방식에서 사용자가 다른 지역으로 이동할 때마다 HLR로 매번 등록하고 질의함으로써 발생되는 HLR로의 시그널링 신호 과부하를 효율적으로 분산, 감소시키며 인접지역 경계간에 발생되는 핑퐁효과가 발생되지 않도록 한다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• 제14권11호
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• pp.1129-1136
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• 2004

The structural modification to install a heavy sensor was made at the front extremities of the foreign-produced helicopter operated in the Korea Navy Mounting the sensor directly to the nose structure is unlikely to be practical because it lowers a dynamic mode of the airframe close to rotor blade passing frequencies, leading to increased helicopter vibration. Unfortunately we have no information on dynamic characteristics of the imported helicopter. So the experimental modal model derived from shake testing on the overall airframe of a working helicopter was used to solve the sensor Installation problems. The sensitivity analysis was done to evaluate what the best of modification woo)d be. Simple ID model and experimental modal data for mount system with sensor were Incorporated into overall dynamic model to assess the effects of the sensor installation on helicopter. Modal testing for the modified helicopter shows that the airframe modes are sufficiently displaced from rotor passing frequencies. The mount system has been proven fight to be sufficiently stable to meet vibration-level requirement for all required operational profiles.

• Journal of the Korean Society for Precision Engineering
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• 제12권8호
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• pp.147-155
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• 1995

Recent experimental studies have been shown that strain gages can be employed to determine either static or dynamic stress intensity factors $K_{I}$ wiht relatively simple experiments. However, it does not usually provide a reliable value of stress intensity factor because of local yielding and limited regions for strain gage placement at the vicinity of the crack tip. This paper attempted to define a valid region and to indicate procedures for locating and orienting the strain gage to determine static toughness $K_{Is}$ accurately form one strain gage readings with respect to varying loadings. The strain gage methods was used for compact tension specimens made of Polycarbonate and PMMA(polymethyl methacrylate). Series expansions of the static and dynamic strain fields are applied. Strain gage orientation and location are then studied to optimize the strain response. Especially, in the dynamic experiment, the specimen employed is an oversized Charpy V-notch specimen which has been modified to provide significant constraint with a large elevation of the flow stress. The impact behavior of the specimen is monitored by placing strain gage near the crack tip. The dynamic toughness $K_{Id}$ is determined from the strain time traces of this gage.e.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.285-289
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• 2009

In this paper, we propose to research the dynamic Matlab/Simulink model of supercapacitor bank(SCB) for a microgrid application. We demonstrated that this model id sufficient to design the control system of entire power storage system, SCB, the chopper and grid connected converter. The proposed dynamic model is simulated with the help of Matlab/$Simulink^{TK}$ in the MTG/PC/SCB hybrid energy system. The study results show that SCB have a good performance to curb power fluctuation in building microgrid application.

• Proceedings of the KIPE Conference
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.458-461
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• 2008

This paper deals with a single-phase impedance-source dynamic voltage restorer (Impedance-DVR) to mitigate voltage sag/swell for the critical loads. The proposed system is composed of passive filter and impedance-source topology inverter. As an ESS(Energy Storage System) of the proposed system is employed the Proton Exchange Membrane Fuel Cells (PEMFC). To calculate and control the compensation voltage, single-phase $^id-^iq$ theory in dq rotating reference frame and PI controller are used. Simulation results under voltage sag and swell are presented to show the performance.