• Journal of Information Science Theory and Practice
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• v.8 no.1
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• pp.45-55
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• 2020

The purpose of this work was to study library website users' actions by tracking their behavior, determining popular content, and identifying browsing patterns and subsequent improvement of access to popular content. The study of behavior models and the use of web analytics has led to the emergence of solutions that improve the usability and functionality of the State Public Scientific-Technological Library of the Siberian Branch of the Russian Academy of Sciences (SPSTL SB RAS) website. These are: identifying user tasks as they are developed, conducting user testing to better understand the event. tracking data and collecting additional data to verify the effectiveness of the changes made. Examining data on the duration of the session and the number of visits will help determine the goals of user visits and develop new recommendations. Usability analysis and testing will make it possible to compare the data obtained using web analytics and the perception of the library site by the users themselves. Recommendations are offered to libraries on the use of data on the real behavior of the target audience of the library website to improve access to library resources and services, increase their relevance and improve information services.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.3
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• pp.172-183
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• 2010

Virtual memory systems (VM) reduce disk I/Os caused by page faults using page prefetching, which reads pages together with a desired page at a page fault in a single disk I/O. Operating systems including 4.4BSD attempt to prefetch as many pages as possible at a page fault regardless of page access patterns of applications. However, such an approach increases a disk access time taken to service a page fault when a high portion of the prefetched pages is not referenced. More seriously, the approach can cause the memory pollution, a problem that prefetched pages not to be accessed evict another pages that will be referenced soon. To solve these problems, we propose an adaptive page prefetching control scheme (APC), which periodically monitors access patterns of prefetched pages in a process unit. Such a pattern is represented as the ratio of referenced pages among prefetched ones before they are evicted from memory. Then APC uses the ratio to adjust the number of pages that 4.4BSD VM intends to prefetch at a page fault. Thus APC allows 4.4BSD VM to prefetch a proper number of pages to have a better effect on reducing disk I/Os, though page access patterns of an application vary in runtime. The experiment of our technique implemented in FreeBSD 6.2 shows that APC improves the execution times of SOR, SMM, and FFT benchmarks over 4.4BSD VM by up to 57%.

• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.138-148
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• 2000

In the mobile computing environment, in order to make copies of important files available when being disconnected the mobile host(client) must store them in its local cache while the connection is maintained. In this paper, we propose the prefetching mechanism for the client to save files which may be accessed in the near future. Our mechanism utilizes analyzer, prefetch-list producer, and prefetch manager. The analyzer records file access patterns of the user in a FAP(File Access Patterns) profile. Using the profile, the prefetch-list producer creates the prefetch-list. The prefetch manager requests a file server to return this list. We set the parameter TRP(Threshold of Reference Probability) to ensure that only reasonably related files can be prefetched. The prefetch-list producer adds the files to a prefetch-list if their reference probability is greater than the TRP. We also use the parameter TACP(Threshold of Access Counter Probability) to reduce the hoarding size required to store a prefetch-list. Finally, we measure the metrics such as the cache hit ratio, the number of files referenced by the client after disconnection and the hoarding size. The simulation results show that the performance of our mechanism is superior to that of the LRU caching mechanism. Our results also show that prefetching with the TACP can reduce the hoard size while maintaining similar performance of prefetching without TACP.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.17-27
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• 2003

In general, an airport access system has influenced on airport terminal operation. The congestion and delay in service facilities at an airport are definitely depended on the patterns of passenger arrival behavior and time spent in a terminal. Therefore, it is necessary to analyze the passenger arrival behavior at an airport to improve the operations at passenger terminal. Passenger arrival patterns to an airport are mainly depended on factors such as the length of access time. reliability of access time. and provision of transport modes, etc. The focus of this paper is to estimate the relationship between the length of access time and passenger's total time spent to board aeroplane. For this, passenger surveys were conducted at the Gimpo International Airport for a large airport and Sacheon Airport for a small size airport. The mathematical relationship between arrival time at an airport prior to the scheduled time of departure(STD) and access time spent was then estimated. It is considered that the results of this study can be used to reduce congestion and delays, thereby to improve the efficiency of the passenger services at the airports.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.1
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• pp.17-25
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• 2008

To achieve the unidirectional airflow in a cleanroom, we need to predict accurately the static pressure losses at the lower plenum and to control properly the opening pressure ratio of access floor panels based on these pressure losses. At first, the present study proposed a correlation to predict the velocity distribution at the lower plenum, because the accuracy to predict pressure losses at the lower plenum depends on how to calculate the velocity correctly against the inner structures at the lower plenum. In the second place, this study proposed correlations which considered the effect of inner structures such as columns, ducts and equipments at the lower plenum on pressure losses. In order to test the accuracy of these correlations, we compared air flow patterns before regulating the opening ratio of access floor with those after regulating. Results after regulating the opening ratio of access floor show good unidirectional uniform airflow pattern. So the present method can be used as an important tool to control the air flow in a cleanroom.

• Quality Improvement in Health Care
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• v.27 no.1
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• pp.20-25
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• 2021

Purpose: The ability to access clinical trials for cancer treatment is important. This study investigated whether regional differences exist in oncologic clinical trial protocols conducted in South Korea. Methods: Records of all approved oncologic clinical trials conducted in 2019 were downloaded from the Republic of Korea Ministry of Food and Drug Safety. The study covered Seoul, the capital area, other metropolitan cities, and provincial areas. Descriptive statistics summarized the distribution patterns of clinical trials by region. Results: A total of 202 oncologic clinical trials were conducted in 63 institutions in 2019. Of these protocols, 186 (92%) were available in Seoul, 120 (59%) in the capital area, 64 (32%) in metropolitan cities, and 66 (33%) in provincial areas. More regional differences in protocol availability were observed in domestic trials, investigator-initiated trials, phase 1 and 2 trials, and smaller-scale trials. Conclusion: Most oncologic clinical trials were conducted in medical institutions located in Seoul, with the rest conducted in the capital area, metropolitan cities, and provincial areas. The findings reveal clear differences in protocol availability between Seoul and the other regions. Measures designed to improve geographical access to oncologic clinical trials may be needed given their growing importance in cancer treatment.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.20-23
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• 2020

This research is to design an effective prefetching method required for DRAM-PCM hybrid main memory systems especially used for big data applications and massive-scale computing environment. Conventional prefetchers perform well with regular memory access patterns. However, workloads such as graph processing show extremely irregular memory access characteristics and thus could not be prefetched accurately. Therefore, this research proposes an efficient dynamical prefetching algorithm based on the regression method. We have designed an intelligent prefetch engine that can identify the characteristics of the memory access sequences. It can perform regular, linear regression or polynomial regression predictive analysis based on the memory access sequences' characteristics, and dynamically determine the number of pages required for prefetching. Besides, we also present a DRAM-PCM hybrid memory structure, which can reduce the energy cost and solve the conventional DRAM memory system's thermal problem. Experiment result shows that the performance has increased by 40%, compared with the conventional DRAM memory structure.

• Korean Journal of Cognitive Science
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• v.12 no.1_2
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• pp.65-76
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• 2001

This study investigated the relationships between hypermedia users information processing styles and navigational patterns. Three aspects of navigational patterns were investigated: (a) navigational breadth patterns which reveal how comprehensively users access, (b) navigational path patterns which display what sequences users follow. and (c) navigational method patterns which show what methods u users employ when using the system. Information processing styles were measured by the Human Information Processing Styles(HIPS) Survey. The subjects were 102 undergraduate students enrolled in management courses at a university. Participation was voluntary 34 students were selected for each of left, right, and integrated information processor group. The subjects interacted with A.g.i.l.e. TrainerTM program to complete two types of searching tasks 'open-ended and closed-ended tasks' Findings indicated that the information processing style seems to play an important role in how an individual interacts with the hypermedia systems.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.7
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• pp.384-393
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• 2002

A Parallel file system is normally used to support excessive file requests from parallel applications in a cluster system, whereas prefetching is useful for improving the file system performance. This paper proposes a new prefetching method, Fips(dynamic File Prefetching Scheme based on file access patterms), that is particularly suitable for parallel scientific applications and multimedia web services in a parallel file system. The proposed prefetching method introduces a dynamic prefetching scheme to predict data blocks precisely in run-time although the file access patterns are irregular. In addition, it includes an algorithm to determine whether and when the prefetching is performed using the current available I/O bandwidth. Experimental results confirmed that the use of the proposed prefetching policy in a parallel file system produced a higher file system performance.

• Nutrition Research and Practice
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• v.6 no.2
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• pp.138-145
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• 2012

The objective of this study was to evaluate the effect of a healthy school tuck shop program, developed as a way of creating a healthy and nutritional school environment, on students' access to healthy foods. Five middle schools and four high schools (775 students) participated in the healthy school tuck shop program, and nine schools (1,282 students) were selected as the control group. The intervention program included restriction of unhealthy foods sold in tuck shops, provision of various fruits, and indirect nutritional education with promotion of healthy food products. The program evaluation involved the examination of students' purchase and intake patterns of healthy foods, satisfaction with the available foodstuffs, and utilization of and satisfaction with nutritional educational resources. Our results indicated that among of the students who utilized the tuck shop, about 40% purchased fruit products, showing that availability of healthy foods in the tuck shop increased the accessibility of healthy foods for students. Overall food purchase and intake patterns did not significantly change during the intervention period. However, students from the intervention schools reported higher satisfaction with the healthy food products sold in the tuck shop than did those from the control schools (all $P$ < 0.001), and they were highly satisfied with the educational resources provided to them. In conclusion, the healthy school tuck shop program had a positive effect on the accessibility of healthy food. The findings suggest that a healthy school tuck shop may be an effective environmental strategy for promoting students' access to healthy foods.