• The Transactions of the Korea Information Processing Society
• /
• v.3 no.6
• /
• pp.1407-1417
• /
• 1996

In recent researches on thread partitioning algorithms break a thread at the long latency operation and merge threads to get the longer threads under the given constraints. Due to this limitation, even a program with little parallelism is partitioned into small-sized threads and context-swithings occur frequently. In the paper, we propose another method array localization about the array name, dependence distance(the difference of accessed element index from loop index), and the element usage that indicates whether element is used or defined. Using this information we can allocate array elements to the node where the corresponding loop activation is executed. By array localization, remote accesses to array elements can be replaced with local accesses to localized array elements. As a resuit,the boundaries of some threads are removed, programs can be partitioned into the larger threads and the number of context switchings reduced.

• Journal of The Korean Association of Information Education
• /
• v.14 no.1
• /
• pp.1-12
• /
• 2010

For hearing-impaired students, it is known that reading ability is the most important means of communication. In the meanwhile, with recent development of wireless communication technologies, mobile devices are used in various education fields. The purpose of this study is to design and implement a mobile system to improve reading ability of hearing-impaired students. For this purpose, "Question Generation Strategy", known as one of the effective methods for improving reading ability, is adopted to make study contents. Also, 2Bi (Bilingual-Bicultural) Approach Model, an attractive model for improving reading ability of hearing-impaired students, is used. Characteristics of the proposed mobile system are as follows. First, the system is developed to let students learn written language usage through repetition and difference of two organically-related curriculums for hearing-impaired students. Second, study contents are made to increase sentence understanding ability using an activity that is to let students read articles, make questions and answer questions for themselves. Third, the proposed system is designed and implemented to allow students to choose study contents individually anytime anywhere depending on their study levels.

• The Journal of Information Systems
• /
• v.17 no.3
• /
• pp.175-204
• /
• 2008

Ubiquitous computing is enhancing computer use by making many computers available throughout the physical environment without being noticed to the users. To facilitate successful adoption and diffusion of ubiquitous systems, it is important to find out the factors affecting their uses. Although researches related to ubiquitous computing have been vigorously conducted from the aspect of system and service provider, there have been very few studies that focus on the user's perspective. This study attempts to find out major factors which are dedicated to the development of ubiquitous systems and services and the relationships between these factors and user satisfaction factors. This study derived the specific factors that characterize ubiquitous services, such as ubiquity, contextual offer, user affinity, privacy, reliability, responsiveness, assurance, and empathy. We also considered service quality factors of ubiquitous services. Then these factors were combined with the Expectation Confirmation Theory (ECT) model and the path analysis was applied to find out the factors affecting user satisfaction and the intention to use the systems. The research findings indicate that ubiquity, contextual offer, privacy, reliability, and responsiveness affect the perceived usefulness. The perceived ease of use and confirmation were found to affect the perceived usefulness. The perceived usefulness, perceived ease of use, and confirmation fumed out to influence the satisfaction. It turned out that the result of this study on the relationship between the perceived usefulness and user satisfaction was identical with the findings in previous related ECT researches. We think this study makes two significant contributions to the development of ubiquitous services. First, this study provides basic implications for better ubiquitous services by considering important characteristics of ubiquitous systems as services. Second, this study also suggests important factors that need to be considered when ubiquitous service providers develop new ubiquitous services to improve user satisfaction and the intention to use the services.

• Journal of the East Asian Society of Dietary Life
• /
• v.16 no.5
• /
• pp.542-549
• /
• 2006

The purpose of this study was to develop a web site providing sound and specific diet and nutritional information for internet users in different age groups to protect themselves from junk nutritional information. Among 660 internal users (436 in their 20s, 154 in their 30s, and 63 in their 40s), 66.4% had access to a computer to get nutritional information. Almost 38% of those in their 20s searched in the internet using the term 'diet', whereas 25.9% of those in their 30s and 27.1% of those in their 40s searched using 'cooking and recipe'(p<0.001). The main purpose of using nutritional information on the internet of the subjects was 'to take care of health'(p<0.001). Seventy percent of subjects answered 'so-so' for the satisfaction about the content of nutritional information that was self-explored. Contents related to nutritional information which needed to be improved was 'sound information' for 47.2% of those in their 30s, 'convenience for the application to daily life' for 51.1% of those in their 20s, and 39.6% of those in their 40s. A specialized nutritional information site must to be developed for users to gain access to reliable and valuable information without difficulty, as the variety of the interested area and application area for each user.

• International Journal of Internet, Broadcasting and Communication
• /
• v.10 no.3
• /
• pp.26-34
• /
• 2018

In this paper, we propose a scheduling scheme that can efficiently serve I/O requests having deadlines in flash storage. The I/O requests with deadlines, namely, real-time requests, are assumed to be issued for streaming services of continuous media. Since a Web-based streaming server commonly supports downloads of HTMLs or images, we also aim to quickly process non-real-time I/O requests, together with real-time ones. For this purpose, we adopt the well-known rate-reservation EDF (RR-EDF) algorithm for determining scheduling priorities among mixed I/O requests. In fact, for the use of an EDF-style algorithm, overhead of task's switching should be low and predictable, as with its application of CPU scheduling. In other words, the EDF algorithm is inherently unsuitable for scheduling I/O requests in HDD storage because of highly varying latency times of HDD. Unlike HDD, time for reading a block in flash storage is almost uniform with respect to its physical location. This is because flash storage has no mechanical component, differently from HDD. By capitalizing on this uniform block read time, we compute bandwidth utilization rates of real-time requests from streams. Then, the RR-EDF algorithm is applied for determining how much storage bandwidth can be assigned to non-real-time requests, while meeting deadlines of real-time requests. From this, we can improve the service times of non-real-time requests, which are issued for downloads of static files. Because the proposed scheme can expand flexibly the scheduling periods of streams, it can provide a full usage of slack times, thereby improving the overall throughput of flash storage significantly.

• Journal of Korea Water Resources Association
• /
• v.43 no.3
• /
• pp.275-282
• /
• 2010

The purpose of culvert design is to determine optimum size for a safe drainage of flood discharge. The present method of culvert design in Korea is generally carried out by using "Road Drainage Design" of Korea Expressway Corporation (1991), which is based on the manual of Federal Highway Association (FHWA) of USA. However, this method may result in subjective error because of using graphs and the usage of nomograph can be a major obstacle for computer modelling. Some errors found in the previous works of culvert design are corrected, and a new logic has been developed for a simple determination of culvert size in this study. FHWA (1985) presents a nomograph to determine the critical water depth and the velocity head for a circular pipe, but in this study simple explicit equations have been developed to determine both respectively.

• Journal of the Korea Convergence Society
• /
• v.11 no.5
• /
• pp.175-182
• /
• 2020

The calculation of the optimal trajectory of the stepped top-down robot was made using a genetic algorithm and a computational torque controller. First, the total energy efficiency was minimized using the Red-Cold Generic Algorithm (RCGA) consisting of reproductive, cross, and mutation. The reproducibility condition related to the position assembly of the start and end of the stride and the joints, angles, and angular velocities are linear constraints. Next, the unequal constraint accompanies the condition for preventing the collision of the swing leg at the corner with the outer surface of the stairs, the condition of the knee joint for preventing kinematic peculiarity, and the condition of no moment in safety in the traveling direction. Finally, the angular trajectory of each joint is defined by fourth-order polynomial whose coefficient is to approximate chromosomes. This is to approximate walking. In this study, the energy efficiency of the optimal trajectory was analyzed by computer simulation through a biped robot with seven degrees of freedom composed of seven links.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.3B
• /
• pp.472-486
• /
• 2000

This paper analysis the performance of joint receiving structure consisting of the decorrelating multiuser detection and beamfromenr-RAKE receive for DS-CDMA communication systems. In asynchronous transmission as the number of simultaneous users increase. the capacity of CDMA system becomes severly reduced due to the nonideal orthogonality between user-assigned PN sequences and improper power control. Accordingly, the CDMA receiving system becomes vulnerable to the multiple access interferences and the near-far problem under multipath fading channel environment. To withstand these undesired performance degradations, this paper proposes the new type of multiuser detection which has a form of the hybrid structure of concatenating beamformer-RAKE receiver and decorrelating multiuser detection. the beam former-RAKE receiver performs temporal and spatial diversity combining with alleviating fading effect and suppressing undesired interferences, and the multiuser detection plays a role of making the receiver robust to the near-far problem. Regarding the individual merit on the usage of either multiuser detection or beamformer-RAKE receiver, the hybrid one is expected to produce the enhanced performance in multipath fading CDMA channel. However major drawback of using decorrelating multiuser detection for practical deployment is arised from its computational complexity , which is exponentially increased as more number of users and transmitted symbols involve. To diminish the computational complexity, this paper exploits an efficient block Toeplitz inversion technique using matrix Levinson polynomial will be introduced. And this paper provided the mathematical analysis to show the efficiency of the proposed joint structure under the multipath propagation environment. And results of a series of exhaustive computer simulations are presented in order to demonstrate the overall performance of the proposed hybrid structure in multipath fading CDMA channel.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.10 s.89
• /
• pp.983-995
• /
• 2004

This paper introduces a pre-compensation filter for compensating dispersive and resonant properties experienced along the usage of non-ideal wideband antennas in impulse communication systems. It has been well blown that the transmitted impulse signal becomes deformed because of dispersive and resonant characteristics. Accordingly, in spite of using ideal template signal at the correlator in coherent receiver, these impairments degrade overall performance attributed to low level of coherence. To overcome this problem this paper exploits a realization technique of pre-compensation filter purposely installed at transmitter whose stability is automatically guaranteed because it has an inversion form of minimum-phase ARMA (Auto-Regressive Moving Average) system. The performance of proposed scheme will be shown in results from computer simulations to verify its affirmative impact on impulse communication system with regarding several distinctively shaped antennas.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.7
• /
• pp.1121-1128
• /
• 2013

The purpose of this paper is to examine the effects of practicing Hatha Yoga on the elderly. I have focused on the changes in subjective pain and a feeling of helplessness in their daily lives of elderly people over 65 who are suffering from chronic back pain. We looked at both men and women over 65, who were not working during the period, all of whom had been experiencing back pain over 6 months. All the subjects have never practiced Hatha Yoga or any other specialized and/or systematic workouts at that time. Among them, the men and women over age 65 with chronic back pain were selected as a group and practiced Hatha Yoga three times a week for eight weeks. In conclusion, the study proves that Hatha Yoga is an effective way for the old over 65 with chronic back pain by acquiring muscular strength and flexibility at the same time.