• Korean Journal of School Psychology
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• v.16 no.3
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• pp.471-499
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• 2019

The purpose of this study was to develop a program that reduces adolescent delinquency and enhances adolescents' social problem-solving, emotional regulation, and self-control skills and to assess the effectiveness of the program. The program was administered in the form of a role-playing game ("RPG") to increase the participants' motivation to participate in and the effectiveness of the therapy. The subjects in this study were 36 adolescents who engaged in delinquent behavior and their 18 homeroom teachers in middle schools located in Seoul and Gyeonggi Province. The subjects were randomly assigned to the experimental group or the comparison group. The experimental group received the proposed RPG-based cognitive behavioral group therapy while comparison group received problem-solving group therapy. Teachers in the experimental group were educated about how to guide their students following each therapy session while teachers in the comparison group did not receive any education. The dependent variables in this study were incidences of delinquent behavior and social problem-solving, emotional regulation, and self-control skill level. Each variable was assessed before treatment, immediately after the end of the full treatment program, and two months after the end of the full treatment program. At the end of the full treatment program, the experimental group engaged statistically significantly in fewer delinquent behaviors and displayed statistically significantly higher levels of social problem-solving, emotional regulation, and self-control skills than the comparison group. These differences persisted until the assessment two months after the end of the full treatment program. Moreover, the experimental group reported higher levels of satisfaction with the treatment program than the comparison group. The findings of this study suggest that this RPG-based cognitive behavioral group therapy program is effective at reducing adolescent delinquency, improving adolescents' social and emotional management techniques and strategies for avoiding delinquency, and in motivating delinquent adolescents to engage more actively in treatment.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.463-471
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• 2012

Objective of this study is to provide basic information for developing more differentiated and targeted forest healing policy and Korean medical healing programs grounded on consumer preference for forest based Korean medical healing tourism products. The internet survey(CAWI) by percentage quota sampling with 400 Seoulite ages over 30 by the age, area, and gender was conducted, and 317 samples were used for a final analysis. 61.5% of the Seoulite associated 'forest bath/walking in the woods/tree' with an image of a forest based Korean medical healing tourism product, and preference for the product and the intention to use were positive at the percentages of 72.9% and 67.5%, respectively. Preferred areas were Seoul/Gyeonggi-do(53.5%) and Gangwon-do(38.8%). 'Stress solving and refreshment', 'taking a forest bath and a walk', and 'maintaining and promoting health' were the main purposes of the use. As for a therapy, 'walking therapy' was most preferred, and 'ergotherapy' was the next. First priority as for a use facility was 'healing trail', and 'professional medical facility' ranked second. Although important decision attributes were ' cost of use', 'food', and 'friendliness of medical staff', all the other sets of attributes related to use convenience, quality of medical service and tourism activities also recorded high, which forecasts higher consumer expectation for the product. As the result showing differences in consumer preference by the demographic segmentation, differentiated and segmented consumer needs should be considered when planing and managing a product. The scope of the study is limited to a demographic segmentation which is a basic stage of understanding consumer preference, therefore more detailed future researches on complicated and multi-dimensional consumer needs are required.

• The KIPS Transactions:PartA
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• v.14A no.7
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• pp.443-450
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• 2007

Performance scalability and storage scalability become important in a large scale cluster of wireless internet proxy cache servers. Performance scalability means that the whole performance of the cluster increases linearly according as servers are added. Storage scalability means that the total size of cache storage in the cluster is constant, regardless of the number of cache servers used, if the whole cache data are partitioned and each partition is stored in each server, respectively. The Round-Robin based load balancing method generally used in a large scale server cluster shows the performance scalability but no storage scalability because all the requested URL data need to be stored in each server. The hashing based load balancing method shows storage scalability because all the requested URL data are partitioned and each partition is stored in each server, respectively. but, it shows no performance scalability in case of uneven pattern of client requests or Hot-Spot. In this paper, we propose a novel dynamic hashing method with performance and storage scalability. In a time interval, the proposed scheme keeps to find some of requested URLs allocated to overloaded servers and dynamically reallocate them to other less-loaded servers. We performed experiments using 16 PCs and experimental results show that the proposed method has the performance and storage scalability as different from the existing hashing method.

• The KIPS Transactions:PartA
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• v.15A no.5
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• pp.275-286
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• 2008

Fast File System(FFS) utilizes large disk bandwidth to improve the write performance of large files. One way to improve the performance is to write multiple blocks of a large file at a single disk I/O through the disk bandwidth. However, rather than disk bandwidth, the performance of small file writes is limited by disk access times significantly impacted by disk movements such as disk seek and rotation because FFS writes each of small files at a single disk write. We propose CW-FFS (Co-Writing Fast File System) to improve the write performance of small files by minimizing the disk movements that are needed to write small files to disks. Its key technique called co-writing scheme is to dynamically collect multiple small files named by a given directory and then write them at a single disk I/O to contiguous disk locations. Co-writing several small files at a single disk I/O reduces multiple disk movements that are needed for small file writes to one single disk movement, thus increasing the overall write performance of write-intensive applications. Furthermore, a file allocation scheme is introduced to prevent co-writing scheme from having a negative impact on disk spatial locality of small files named by a given directory. The measurement of our technique implemented in the OpenBSD 4.0 shows that CW-FFS increases the performance of small file writes over FFS in the range from 5 to 35% in the Postmark benchmark.

• Journal of KIISE
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• v.43 no.3
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• pp.304-313
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• 2016

We present a novel memory-efficient parallel ray casting algorithm for unstructured grid volume rendering on multi-core CPUs. Our method is based on the Bunyk ray casting algorithm. To solve the high memory overhead problem of the Bunyk algorithm, we allocate a fixed size local buffer for each thread and the local buffers contain information of recently visited faces. The stored information is used by other rays or replaced by other face's information. To improve the utilization of local buffers, we propose an image-plane based ray grouping algorithm that makes ray groups have high coherency. The ray groups are then distributed to computing threads and each thread processes the given groups independently. We also propose a novel hash function that uses the index of faces as keys for calculating the buffer index each face will use to store the information. To see the benefits of our method, we applied it to three unstructured grid datasets with different sizes and measured the performance. We found that our method requires just 6% of the memory space compared with the Bunyk algorithm for storing face information. Also it shows compatible performance with the Bunyk algorithm even though it uses less memory. In addition, our method achieves up to 22% higher performance for a large-scale unstructured grid dataset with less memory than Bunyk algorithm. These results show the robustness and efficiency of our method and it demonstrates that our method is suitable to volume rendering for a large-scale unstructured grid dataset.

• Journal of KIISE:Databases
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• v.35 no.3
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• pp.257-271
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• 2008

Wireless broadcast environments has character that a number of mobile client can receive data streaming from central server no matter how they are so many. Because it is asymmetric bandwidth in that uplink and downlink bandwidth are different. This advantage helps wireless broadcast environments is used in many applications. These applications work almost read operation and need control concurrency using transaction unit. Previous concurrency control scheme in single channel is not adapted in multi channel environments because consistency of data are broken when a mobile client tunes in a broadcast cycle in a channel and then move into another channel and listen to different broadcast cycle with already accessed broadcast cycle. In this paper, we propose concurrency control for read-only mobile transactions in multiple wireless broadcast channel. First of all, we adapt index and data dedicated channel and propose LBCPC(Longest Broadcast Cycle Per Channel) as new unit of consistency. In index dedicated channel, it is repeatedly broadcasted data in same BCPC(Broadcast Cycle Per Channel) until LBCPC. And mobile transaction executes validation using control information every LBCPC. As a result, consistency of data is kept and average response time is shorter than one in single channel because waiting time for restart reduces. And as control information is broadcasted more frequently than in single channel, it is guaranteed currency about data accessed by transaction. Finally, according to the simulation result, we verify performance of our scheme in multi channel as comparing average response time with single channel.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.5
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• pp.38-48
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• 2007

In ubiquitous environment, sensor networks that sense and transmit surrounding data without human intervention will become more important. If sensors are installed for detecting vehicles and measuring their speed in the road and that real-time information is given to drivers, it will be very effective for enhancing safety and controlling traffic in the road. In this paper, we proposed a new reliable and real-time sensor MAC protocol between AP and sensor nodes in order to provide real-time traffic flow information based on ubiquitous sensor networks. The proposed MAC allocates one TDMA slot for each sensor node on the IEEE 802.15.4 based channel structure, introduces relayed communication for distant sensors, and adopts a frame structure that supports retransmission for the case of errors. In addition, the proposed MAC synchronizes with AP by using beacon and adopts a hybrid tracking mode that supports economic power consumption according to various traffic situations, We implemented a simulator for the proposed MAC by using sim++ and evaluated various performances. The simulation results show that the proposed MAC reduces the power consumption and reveals excellent performance in real-time application systems.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.394-404
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• 2020

Purpose: This study was carried out to examine the applied effects of an oriental nursing intervention program on the physical health status, activities of daily living (ADL), depression, life satisfaction, and Yangseng of the elderly living in the community. Methods: This was a quasi-experimental study using a non-equivalent control group pretest-posttest. Study participants were total 79 elderly (experimental: n=39, control: n=40) who aged 65 or over with normal cognitive status and available communication in D community, Seoul, South Korea. They were recruited by convenient sampling, and assigned randomly. The oriental nursing intervention program composed Pal-Dan-Gum as Qi-gong therapy and Kyunglak exercise. This program consisted of 20 sessions total for 10 weeks. Measures were CMI(Cornell Medical Index), Instrumental ADL (Activities of Daily Living), GDS(Geriatric Depression Scale), geriatric life satisfaction scale, and Yangseng scale. Data were analyzed by SPSS WIN21.0 using descriptive statistics, x²-test, and independent t-test. Results: There were statistically significant differences in the mean scores of physical health status (t=10.295, p<.001), ADL (t=7.571, p<.001), depression (t=-15.434, p<.001), life satisfaction (t=21.257, p<.001), and Yangseng (t=9.527, p<.001) between intervention and control groups. Conclusions: Oriental nursing intervention program was effective for improving the physical health status, ADL, depression, life satisfaction, and Yangseang of the elderly living in the community. This intervention program can be implied for health promotion of elderly living in the community.

• Korean Journal of Cognitive Science
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• v.27 no.3
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• pp.355-376
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• 2016

We used holes defined by color similarity (Experiment 1) and binocular disparity (Experiment 2) to study how the inner contour of an object (i.e., boundary of a hole in it) is encoded in visual working memory. Many studies in VWM have shown that an object's boundary properties can be integrated with its surface properties via their shared spatial location, yielding an object-based encoding benefit. However, encoding of the hole contours has rarely been tested. We presented objects (squares or circles) containing a bar under a change detection paradigm, and relevant features to be remembered were the color of objects and the orientation of bars (or holes). If the contour of a hole belongs to the surrounding object rather than to the hole itself, the object-based feature binding hypothesis predicts that the shape of it can be integrated with color of an outer object, via their shared spatial location. Thus, in the hole display, change detection performance was expected to better than in the conjunction display where orientation and color features to be remembered were assigned to different parts of a conjunction object, and comparable to that in a single bar display where both orientation and color were assigned into a single bar. However, the results revealed that performance in the hole display did not differ from that in the conjunction display. This suggests that the shape of holes is not automatically encoded together with the surface properties of the outer object via object-based feature binding, but encoded independently from the surrounding object.

• Journal of Internet Computing and Services
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• v.10 no.4
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• pp.87-103
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• 2009

Grid computing is an expanded technology of distributed computing technology to use low-cost and high-performance computing power in various fields. Although the purpose of Grid computing focuses on large-scale resource sharing, innovative applications, and in some case, high-performance orientation, it has been used as conventional distributed computing environment like clustered computer until now because Grid middleware does not have common sharable information system. In order to use Grid computing environment efficiently which consists of various Grid middlewares, it is necessary to have application-independent information system which can share information description and services, and expand them easily. Thus, in this paper, we propose a semantic information system framework based on web services and ontology for Grid computing environment, called WebSIS. It makes application and middleware developer easy to build sharable and extensible information system which is easy to share information description and can provide ontology based platform-independent information services. We present efficient ontology based information system architecture through WebSIS. Discovering appropriate resource for task execution on Grid needs more high-level information processing because Grid computing environment is more complex than other traditional distributed computing environments and has various considerations which are needed for Grid task execution. Thus, we design and implement resource information system and services by using WebSIS which enables high-level information processing by ontology reasoning and semantic-matching, for automation of task execution on Grid.