• International journal of advanced smart convergence
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• 제9권2호
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• pp.164-172
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• 2020

The interest and importance of the convergence services for healthcare expand more and more as the average life expectancy increases. Convergence of ICT and healthcare technology unfold efficient and quick health services. Recently, healthcare services provide to clients with apps over web. On-demand wireless data broadcast supports any number of clients to access their desired data items dynamically by responding the needs for data items from the clients. In this paper, we propose an on-demand system to broadcast FHIR bundles for efficient healthcare services. We use time-parameterized replacing policy for renewing the bundle items on the wireless broadcast channel. The policy lets the on-demand broadcasting dynamic by controlling the time duration for the bundles to reside over the wireless channel. With simulation studies using an implemented testbed, we evaluate the performances of the proposed system in access time and tuning time. For evaluation, we compare the time-parameterized replacing policy of the proposed system with regular-number replacing policy. The proposed time-parameterized replacing policy shows shorter access time than the regular-number replacing policy because the policy responds more actively and dynamically to the change of the needs of the clients for FHIR bundles.

• 융합보안논문지
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• 제8권4호
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• pp.65-71
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• 2008

대용량 하드디스크의 등장으로 많은 자료를 컴퓨터의 하드디스크에 저장할 수 있게 되었다. 하드디스크의 용량이 커지면서 저장되어 있는 파일 및 디렉토리가 증가하여 디지털 포렌식 분야에서도 탐색해야 하는 정보가 증가하게 되었다. 대용량 하드디스크에서 증거로 활용될 수 있는 파일 정보를 탐색하기 위해서는 윈도우 시스템에서 제공해주는 파일관리 함수군을 주로 이용한다. 하지만, 이 방법은 파일과 디렉토리의 수가 많을 경우 처리속도가 느리며, 파일 정보를 읽을 경우 파일의 접근시간이 변경된다. 또한, 운영체제 또는 응용 프로그램에 의해 이미 사용중인 파일의 경우 접근이 불가능하다는 단점이 있다. 본 논문에서는 대용량 하드디스크에 저장되어 있는 파일 및 디렉토리를 빠르게 탐색하기 위한 방법으로 하드디스크의 물리적 섹터에 접근하여 NTFS의 MFT 정보를 획득하고, 획득된 MFT 정보를 기반으로 증거파일을 탐색하는 방법을 제시하고 구현하였다.

• 한국도서관정보학회지
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• 제25권
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• pp.19-50
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• 1996

The purpose of this paper is to study on ownership and access in future library. For this purpose, this is criticized about recognition regarding future library of Library and Information Science researchers in Korea. And, this is reviewed the present stages of collection development and a role of future books, future libraries and future librarians in Korea. The result of this study is known unrealistic reality analysis and forecast surrounding future library discourse and at the same time that following Western model is not fit for future library in Korea. This study is proposed resolving of problems to access based on physical collection in future library.

• 한국주거학회논문집
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• 제20권5호
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• pp.9-21
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• 2009

This study classified visual perception types of access space at 17 five-star hotels in Jejudo and examined their cognitive characteristics and image formation structures in an effort to provide basic information important for designing the elevation and the access spaces of a hotel. The results of this study are as follows. Access space image of experimental hotels showed more negative evaluations at both city hotels and resort hotels, viewing angle (upward angle) was also positively evaluated between $10^{\circ}{\sim}12^{\circ}$ and $18^{\circ}$ and central type in arrangement type and detour access and straight access types in access circulation type were positively evaluated. When viewed from an upward angle of $10^{\circ}$ to $12^{\circ}$, the most important factors were as plasticity, decorativeness, and creativity; from $18^{\circ}$ it was such factors as harmony and peculiarity; and at $45^{\circ}$ it was factors like decorativeness and stability. In considering the various access types, the most important factors in a straight access type were peculiarity and harmony; for one-time curved access type it was by decorativeness, creativity, Peculiarity, and stability; and for detour access types it was decorativeness, stability, and peculiarity. Influential of factors affecting image formation and plasticity and harmony factors and the form had more influences on image formation.

• 한국정보통신학회논문지
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• 제17권6호
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• pp.1419-1424
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• 2013

PONs (passive optical networks)은 운용비용이 저렴하고 높은 대역폭을 제공하기 때문에 가입자망에서 각광을 받고 있다. 최근에는 WDM (wavelength-division multiplexing)와 TDM (time-division multiplexing)을 결합한 TWDM PON이 가입자망에서의 새로운 해답으로 여겨지고 있다. 본 논문에서는 TWDM PON에 대한 새로운 MAC (media access control) protocol을 제안한다. 또한 TWDM PON에 대한 새로운 동적대역할당 방법을 제안하고 성능을 평가한다.

• Journal of information and communication convergence engineering
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• 제10권2호
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• pp.117-122
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• 2012

We propose a hybrid multiple access (HMA) for uplink orthogonal frequency division multiple access (OFDMA) systems, which combines two resource sharing schemes: a scheduling-based resource allocation (SBRA) scheme and a contentionbased resource allocation (CBRA) scheme. The SBRA scheme is appropriate for non-real time high data rate traffic, and, CBRA is appropriate for near-real time low/medium data rate traffic. Thus, the proposed HMA scheme supports various types of traffic. As a CBRA scheme, our proposed random frequency hopping (RFH)-OFDMA scheme was presented. Simulation results show that the proposed HMA yields the best performance among various resource allocation schemes for uplink OFDMA systems.

• 한국통신학회논문지
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• 제21권5호
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• pp.1230-1239
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• 1996

This paper analyzes matched-filter acquistion performance of a direct-sequence spread-specturm multiple-access system in a Rayleigh fading channel. For an application of multiple access system, multiple access interference is considered in the performance analysis. A signal flow graph technique is used to derive mean acquisition time in terms of detection and false alarm probabilities. As aresult of performance analysis, it is shown that mean acquisition time increases as fading rate becomes faster andthe numbre of users increases, and it decreases as a matched-filter length becomes logner. The variation of parameter values hs much influence on acquisition performance as SNR/chip becomes smaller.

• Journal of Communications and Networks
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• 제14권4호
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• pp.418-428
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• 2012

With the requirement for providing multiple levels of access control for group members, many group key management schemes designed for hierarchical access control have been put forward. However, most of these schemes focus on the efficiency of group key establishment and rekeying in centralized environments. This paper proposes an integrated group key agreement (IGK) scheme for contributory environments. The IGK scheme employs the integrated key graph to remove key redundancies existing in single key trees, and reduces key establishment and rekeying time while providing hierarchical access control. Performance analyses and simulations conducted with respect to computation and communication overheads indicate that our proposed IGK scheme is more efficient than the independent group key agreement scheme.

• 한국시뮬레이션학회논문지
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• 제8권2호
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• pp.1-11
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• 1999

Advanced information communication processing system mainly consists of network access subsystems and a switching system. This paper provides performance analysis of a typical network access subsystem. The network access subsystem is modeled as a queueing network including a server providing polling services. The arrival process of messages to an input buffer is regarded as a Poisson process. Performance measures such as mean input buffer length and mean waiting time of meassages are obtained through simulation, for it is impossible to calculate the performance measures using an analytical method. Hybrid simulation is used to reduce the variance of estimators. The variance reduction effect on the mean waiting time is reported.

• 한국컴퓨터정보학회논문지
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• 제20권9호
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• pp.1-10
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• 2015

In this paper, we propose a new variable latency L1 data cache architecture for multi-core processors. Our proposed architecture extends the traditional variable latency cache to be geared toward the multi-core processors. We added a specialized data structure for recording the latency of the L1 data cache. Depending on the added latency to the L1 data cache, the value stored to the data structure is determined. It also tracks the remaining cycles of the L1 data cache which notifies data arrival to the reservation station in the core. As in the variable latency cache of the single-core architecture, our proposed architecture flexibly extends the cache access cycles considering process variation. The proposed cache architecture can reduce yield losses incurred by L1 cache access time failures to nearly 0%. Moreover, we quantitatively evaluate performance, power, energy consumption, power-delay product, and energy-delay product when increasing the number of cache access cycles.