• The KIPS Transactions:PartA
• /
• v.8A no.2
• /
• pp.107-116
• /
• 2001

A multithreaded model is a hybrid one which combines locality of execution of the von Neumann model with asynchronous data availability and implicit parallelism of the dataflow model. Much researches that have been made toward the advanced performance of multithreaded models are about the cache memory which have been proved to be efficient in the von Neumann model. To use an instruction cache or operand cache, the multithreaded models must have cache memories. If cache memories are added to the multithreaded model, they may have the disadvantage of high implementation cost in the mode. To solve these problems, we did not add cache memory but applied the method of executing the caching by using available registers of the multithreaded models. The available register-based caching method is one that use the registers which are not used on the execution of threads. It may accomplish the same effect as the cache memory. The multithreaded models can compute the number of available registers to be used during the process of the register optimization, and therefore this method can be easily applied on the models. By applying this method, we can also remove the access conflict and the bottleneck of frame memories. When we applied the proposed available register-based caching method, we found that there was an improved performance of the multithreaded model. Also, when the available-register-based caching method is compared with the cache based caching method, we found that there was the almost same execution overhead.

• Journal of the korean veterinary medical association
• /
• v.38 no.4
• /
• pp.376-382
• /
• 2002

호주의 많은 소동물 임상수의사들이 최근에 관심을 갖고 있는 부분은 개의 아토피(Canine Atopy)에서의 알러지-특이성(Allergen-specific)IgE에 쓰이는 혈청 ELISA (Enzyme-Linked Immuno-Sorbent Assay, 효소결합면역흡착검사)테스트의 활용 가능성에 관한 것이다. 희망사항은 개 아토피의 진단과 치료에 있어서 도움이 되도록 접근할 수 있는 시험(Accessible test)일 것이다. 아토피(Atopy)는 진단과 치료를 실패시키는 질병이며, 새로운 ELISA라도 이 문제를 쉽게 해결하여 주지 못한다. 개의 아토피에서 알려진(Allergens)들을 분석하는 데 쓰이는 혈청 ELISA처럼 아주 정확하게 특성화되어져야 한다. 해당 개는 아토피성(Atopic)으로서 진단되어져야만 되고 그 다음에 치료에 지침이 되도록 개별 알러진 동정(Individual allergen identification)용 ELISA로 개의 혈액을 스크린하는데 적합하여야 한다. ELISA와 피내접종시험(Internal testing)방법은 상관도가 낮고 그렇기 때문에 어떤 시험이 더 신뢰할 수 있는 것일까? 이러한 사실은 논쟁의 여지가 있으며 이상의 2가지 시험들이 옳다면 각각의 상응하는 각각 다른 아형(Subtypes)의 아토피라고 볼 수있다. 아마도 알러진들은 경피적으로 흡수되어 아토피성피부염으로 되어진다. 그것은 인체에서 건초열(Hay fever)이나 천식(Asthma)과 같이 흡입에 의해 일으키는 유사한 증후군동종 (Syndrome akin)과 같은 접근의 초기양식(Primary mode of access)으로부터 생기는 다른 유사한 질병과정이 되어질 수도 있다. 이러한 2가지 증후군은 함께 병발하는 경우가 있다. 의학에서는 피부 반점시험방법의 예비조사연구(Preliminary research with skin patch testing in medicine)는 아토피성 피부염을 야기하는 알러진들의 경피흡수경로의 개념을 지지해준다. 흡인 알러진들을 사용한 개들에서의 도전 시험(Challenge tests)들은 거의 대부분이 비-피부학적 임상증상들을 발현하였다. 모든 증거가 분명히 나타나도록 미래의 조사연구를 인도해 주는 게 필요하며 개 아토피의 정의와 진단을 둘러싼 수수께끼를 해결하는데 도움이 될 것이다.

• Journal of KIISE:Information Networking
• /
• v.33 no.5
• /
• pp.355-368
• /
• 2006

This paper introduces a new split-TCP approach for improving TCP performance over IEEE 802.11-based wireless LANs. TCP over wireless LANs differently from wired networks is not aggressive, which is a fundamental reason for poor performance. Therefore, we propose TAS (TCP-Aware Sub-layer) to migigate this problem. Our scheme extends the split-connection approach that divides a connection into two different connections at a split point such as an access point (AP). Using TAS, a wireless node emulates TCP ACK packets using MAC ACK frames, instead of receiving real TCP ACK packets. We compared TAS with both normal TCP and I-TCP (Indirect TCP) by NS2 simulation. Results show that TAS achieves higher throughput, more fair resource allocation and, in power-saving mode, shorter delays.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.12B
• /
• pp.1647-1658
• /
• 2011

This paper suggests the methods to improve the wireless backhaul link of the Relay FDD mode that 3GPP LTE-Advanced supports. New RRC message and Relay startsup procedure are introduced to apply Carrier Aggregation in the Relay wireless backhaul. Also, we design new reference signal that makes Type 1 Relay operated in full-duplexing, expecting to maximize the radio resource utilization. And, we propose the efficient configuration for the periodic uplink control information under the backhaul subframe allocation method in LTE-Advanced Relay. Hereafter, the standard activities in the 3GPP RAN is supposed to focus on the improvement of the LTE-Advanced features. Therefore, the suggestions in this paper are expected to be actively discussed in the LTE-Advanced future releases.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.2
• /
• pp.111-118
• /
• 2008

In this paper a novel medium access control mechanism is investigated as a means to support real-time services. The primary goal is to provide constant-bit-rate voice call services to pairs of autonomous mobile nodes operating in ad hoc networks. Here, a time-slot reservation based MAC is considered to provide real-time voice calls and a new MAC called the time-slot reservation coordination function(TRCF) is presented. In addition to this isochronous type MAC protocol development, the proposed protocol is modeled using a Markov chain in order to predict its behavior. The performance of TRCF is analytically derived and the performance measures such as average wait time taken for a call connection and throughput are obtained.

• Journal of Korean Society of Forest Science
• /
• v.88 no.1
• /
• pp.63-72
• /
• 1999

In this study, a relational database program to manage the data involved in forest planning was developed in such a way to simulate the whole process of 'Younglim' planning in Korean National Forest System. Using the pull-down menu system of various functions required for developing 'Younglim' plan, the database program can handle the data of forest inventory, 10-year working plans, annual working plans and the history of forest operations automatically and simultaneously. The model was designed to run under the environment of Korean version of Windows 95. Visual Basic 5.0 was used as the basic tool for programming and Microsoft ACCESS as the basic engine of the database system. In this paper, the process of designing the structure of database program following the process of 'Younglim' plan and the structure of the model are discussed. In addition, the functions of menu system are presented using the screen-mode output windows of the model.

• The KIPS Transactions:PartB
• /
• v.10B no.5
• /
• pp.535-542
• /
• 2003

This study is concerned with an assistive technology which reduces color blinds´s confusion when they access electronic documents including color objects in their computers. In this study, 1 restrict the assistive technology would apply to windows operating system, 256 color mode and implement to minimize color distortion which occurs in multi window environments because of color approximation process. As a basic palette, I use a 216 colors web safe palette which the Christine proposed as a standard for color blind, expand it to 256 colors to apply all computer displays using Microsoft Windows as its operating system and implement it as windows application. To test its effectiveness, I use a simulator for dichromats, as results of the test, the developed color vision deficiency correction S/W is effective to reduce the confusion. It is more effective to use the implemented S/W in both of design and client process for electronic documents.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.5
• /
• pp.1-13
• /
• 2009

Filter cache has been introduced as one solution of reducing cache power consumption. More than 50% of the power reduction results from the filter cache, whereas more than 20% of the performance is compromised. To minimize the performance degradation of the filter cache, the predictive filter cache has been proposed. In this paper, we review the previous filter cache predictors and analyze the problems of the solutions. As a result, we found main problems that cause prediction misses in previous filter cache schemes and, to resolve the problems, this paper proposes a new prediction policy. In our scheme, some reference bit entries, called MSBs, are inserted into filter cache and BTB, to adaptively control the filter cache access. In simulation parts, we use a modified SimpleScalar simulator with MiBench benchmark programs to verify the proposed filter cache. The simulation result shows in average 5% performance improvement, compared to previous ones.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.5
• /
• pp.7-15
• /
• 2007

In wireless communication networks, single-radio single-channel architecture degrades throughput and end-to-end delay due to half-duplex transmission of wireless node and route intra interference. Also, In contention-based MAC (Medium Access Control) architecture, channel contention reduces throughput and packet collision enlarges end-to-end delay. In this paper, we use multi-radio multi-channel architecture which will make wireless node to operate in full duplex mode, and exclude route intra interference. Based on this architecture, we propose a new link metric, ccf which reflects the characteristics of a contention-based wireless link, and propose a routing path metric MCCR considering channel switching delay and route intra interference. MCCR is compared with MCR by simulation, the performance of a route established by MCCR outperforms the performance of a route by MCR in terms of throughput and end-to-end delay.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.3A
• /
• pp.267-277
• /
• 2011

Like other wireless network protocols, IEEE 802.15.4 adopts CA (Collision Avoidance)algorithm to avoid the early collision of a new packet by randomizing its first transmission time rather than its immediate delivery. The traditional CA scheme of IEEE 802.15.4, however, selects the random access time from the predetermined range without considering the degree of current congestion. It probably causes either a long delay to settle in the suitable range for the current network load or frequent clashes especially during the long lasting heavy traffic period. This paper proposes an ACA(Adaptive Collision Avoidance) algorithm adapting the initial backoff range to the undergoing collision variations. It also introduces a mathematical model to predict the performance of ACA algorithm added to IEEE 802.15.4. With only small deviations from corresponding simulations, our analytical model shows that ACA technique can improve the throughput of IEEE 802.15.4 by up-to 41% maximally in addition to shortening the packet delays.