• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.547-556
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• 2019

Thinned, small larch logs have small diameters and no value-added final use, except as wood chips, pallets, or fuel wood, which are products with very low economic value; however, their mechanical strength is suitable for structural applications. In this study, small larch logs were sawed, dried, and cut into square timbers (with a $90mm{\times}90mm$ cross section) that were laterally glued to form core panels used to manufacture cross-laminated timber (CLT) wall panels. The surface and back of these core panels were covered with 12-mm-thick structural plywood panels, used as cross bands to obtain three-ply CLT wall panels. This attachment procedure was conducted in two different ways: gluing and pressing (CGCLT) or gluing and nailing (NGCLT). The size of the as-manufactured CLT panels was $1,220mm{\times}2,440mm$, the same as that of the plywood panels. The final wall panels were tested under lateral shear force in accordance with KS F 2154. As the lateral load resistance test required $2,440mm{\times}2,440mm$ specimens, two CLT wall panels had to be attached in parallel. In addition, the final CLT panels had tongued and grooved edges to allow parallel joints between adjacent pieces. For comparison, conventional light-frame timber shear walls and midply wall systems were also tested under the same conditions. Shear walls with edge nail spacing of 150 mm and 100 mm, the midply wall system, and the fabricated CGCLT and NGCLT wall panels exhibited maximum lateral resistances of 6.1 kN/m (100%), 9.7 kN/m (158%), 16.9 kN/m (274%), 29.6 kN/m (482%), and 35.8 kN/m (582%), respectively.

• Journal of the Korean Society for information Management
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• v.30 no.1
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• pp.71-92
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• 2013

This study compared the everyday-life information behaviors of urban and rural adolescents to suggest ways that school library information services can better meet the information needs of each of these groups. It focused its comparison not only on the everyday-life information-seeking behaviors but also on kinds of information grounds and barriers forming information grounds. Two qualitative methods, written activity logs and semi-structured in-depth interviews, were used to examine everyday-life information behaviors of adolescents. It is expected that the proposed strategies will be used in planning actual school library information services for urban or rural youths.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.1
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• pp.86-96
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• 2015

A lot of research works in the BPM area focuses on the development of new techniques in process mining. Even though the application of process mining to analyze real life process logs is important, only few case studies are available. Thus, in this paper, we conduct a case study on how to analyze a real life process log which comes from a Korean company in the heavy industry area. We analyze a customer service process that consists of a series of activities to enhance the level of customer satisfaction. In this case study, five research questions are derived based on collected questions from the company. Then we focus on bottleneck analysis, basic performance analysis and pattern analysis that are selected in order to answer the research questions. The analysis shows some abnormal behaviors in the process and possible ways to improve current processes are suggested.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.45-54
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• 2003

The density and strength of wood is affected by degradations and defects, such as voids and knots. Old wooden structures such as traditional cultural properties have been deteriorated by these types of defects. They were evaluated by a visual observation that is difficult to evaluate the inner deterioration in structures. In this study, three nondestructive testing techniques were investigated to detect the wooden structural members. Ultrasonic stress wave tests, drilling resistance tests and visual inspections were used to examine the structural wood members. Patterns of Resistograph using by drilling resistance tests could indicate the features of internal wood such as voids, knots, decay, fungi, and so on. The technique just like as ultrasonic stress wave tests, however, difficult to detect exactly area where small amounts of internal deterioration in logs are. In spite of results of ultrasonic stress wave test, the internal deterioration of wooden structural members could be evaluated by the relationship between ultrasonic stress wave tests and drilling resistance tests.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.527-533
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• 2009

This study was performed to investigate the escape of pine wood nematode (PWN), Bursaphelenchus xylophilus, from two vector species (Monochamus alternatus and M. saltuarius) through oviposition and feeding behavior. First, we checked number of PWNs escaped from M. alternatus emerged from three different cases of pine logs. In case A, healthy pine trees were cut into logs and left in pine forest infected with PWN. In case B, healthy pine trees were cut into logs, left in large screen cage, and let them oviposited by M. alternatus emerged from pine trees infested with PWN. In case C, pine trees which were harboring M. alternatus were cut into logs, and PWN was inoculated artificially. The M. alternatus adults emerged from the above three cases of pine logs were checked in the next year to know how many PWN they were harboring in their bodies. The percentages of M. alternatus harboring PWN (18.3 and 15.6%, respectively) and number of nematodes per vector ($5,713.1{\pm}9,248.3$ and $2,034.1{\pm}4,746.8$ PWNs, respectively) in case A and B logs are similar to each other. However, the percentage and the number in case C (38.3% and $20,083.1{\pm}32,188.3$ PWNs) were higher than those of case A and B. Among 52 M. alternatus adults harboring PWN from all the three cases, 20 adults (38.5%) were harboring more than 5,000 PWNs per beetle. And these 20 adults were harboring 97.9% of the total PWNs in 52 adults. Second, we checked the daily escape of PWNs from M. alternatus and M. saltuarius collected at pine forest infested with PWN. The PWN escaped from their vector body for $34.9{\pm}12.4$ days for M. alternatus, and for $23.9{\pm}16.2$ days for M. saltuarius, reaching at peak escape during the 2nd week of emergence of the two vector species. A 44.5 and 47.2% to the total PWNs escaped from vector body within 2 weeks of vector emergence for M. alternatus and M. saltuarius, respectively. The number of PWNs escaped from each vector was $3,570.6{\pm}5,189.2$ and $1,556.2{\pm}1,710.3$ for M. alternatus and M. saltuarius, respectively.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1353-1358
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• 2005

A rapid and quantitative real-time PCR was developed to target the invasion A (invA) gene of Salmonella spp. We developed quantitative standard curves based on plasmids containing the invA gene. Based on these curves, we detected Salmonella spp. in artificially contaminated buffered peptone water (BPW) and milk samples. We were able to determine the invA gene copy number per ml of food samples, with the minimum detection limit of $4.1{\times}10^{3}$ copies/ml of BPW and $3.3{\times}10^{3}$ copies/ml of milk. When applied directly to detect and quantify Salmonella spp. in BPW and milk, the present real-time PCR assay was as sensitive as the plate count method; however, copy numbers were one to two logs higher than the colony-forming units obtained by the plate count methods. In the present work, the real-time PCR assay was shown to significantly reduce the total time necessary for the detection of Salmonella spp. in foods and to provide an important model for other foodborne pathogens.

• Journal of KIISE:Databases
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• v.37 no.5
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• pp.238-249
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• 2010

Flash memory has been studied as a storage medium in order to improve the performance of the system using its high computing speed in the DBMS field where frequent data access is needed. The most difficulty using the flash memory is the performance degradation and the life span shortening of flash memory coming from inefficient in-place update. Log based approaches have been studied to solve inefficient in-place update problem in the DBMS where write operations occur in smaller size of data than page frequently. However the existing log based approaches suffer from the frequent merging operations, which are the principal cause of performance deterioration. Thus is because their fixed log area management can not guarantee a sufficient space for logs. In this paper, we propose non-fixed log area management technique that can minimize the occurrence of the merging operations by promising an enough space for logs. We also suggest the cost calculation model of the optimal log sector number minimizing the system operation cost in a block. In experiment, we show that our non-fixed log area management technique can have the improved performance compared to existing approaches.

• Journal of Digital Forensics
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• v.12 no.3
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• pp.9-17
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• 2018

Smartphone have become commonplace because they have the advantage of facilitating communication with others and making life easier. The smartphone's system log stores various data related to the user actions. Since 2015, Huawei has been growing rapidly, with its sales volume increasing and it was ranked second in the world in three years. The use of Huawei smartphones by many users means that Huawei smartphones are likely to be used to detect traces of criminal investigations, so we need to study system logs of Huawei smartphones. Therefore, in this paper, we analyze system log which is forensically meaningful for Huawei smartphone. We also propose how to use logs in forensic investigation.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.457-464
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• 2017

This study has utilized the stand density management diagram to devise an efficient management standard for the stand density for Pinus densiflora that secures the health of the stands and predicted the harvest goals. The appropriate stand control level was estimated by modeling the relationship of the relative yield index (Ry) to the ratio of slender trees within the stand through an exponential function; the coefficient of determination ($R^2$) was found to be 0.424 according to the estimation. The ratio of slender trees within the stand showed a tendency of rapid increase at a certain relative yield index; with this relational function, the appropriate Ry value of 0.84 was obtained. By estimating the curve of the Ry value 0.84, which was the appropriate stand density management level, as well as the height of dominant trees in the central region of Korea, the production objective for each site index was set. Assuming that the final age by the site indices ranged from 10 to 16 for the P. densiflora in central region of Korea, the number of production was estimated to be between 426 to 1,311 trees per ha. It was predicted that the production of medium-diameter logs larger than 30 cm in diameter is possible for the target DBH at a site index of more than 16; small-diameter logs larger than 20 cm in diameter for site indices 12 and 14 enabled, and small-diameter logs of less than 20 cm for site index 10.

• Journal of the Korean Society for information Management
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• v.30 no.2
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• pp.269-295
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• 2013

This study purported to study the uses of information and communication technology (ICT) tools in their daily life among the undergraduate and graduate students majoring science and engineering. It also examined the purposes of the uses of the major ICT tools, the differences in their information technology uses between graduate and undergraduate students. The data were collected from 83 undergraduate and graduate students from four universities using content analysis of an observational logs and a survey questionnaire. The observational logs were collected using an instant message application available on a smart phone. Study results revealed desktop computers, laptop computers, and smart phones as the three most heavily used ICT tools among the participants and typical situations students use each of the three tools. There were also sharp distinctions between graduate and undergraduate students in their selection of the tools, and distinctions between work and non-work situations. The findings of this study can be used to redesign information services and systems for the scientists and engineers in the next generation.