• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.1-10
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• 2006

The objective of this study was to elucidate the microscopic patterns of decay caused by brown-rot fungi of Tyromyces palustri and Gloeophyllum trabeum in Korean red pine (Pinus densiflora) and radiata pine (Pinus radiata) woods through light and electron microscopies. The ultrastructural changes of cell walls attacked by the two brown-rot fungi were compared in this respect. Macroscopically, radiata pine showed more ring and radial checks than Korean red pine. Microscopically, with the progress of decay, spiral checks associated with cross-field pits and bore holes in the cell wall were more remarkably numerous in the radiata pine than in the Korean red pine. In the radiata pine, G. trabeum produced more spiral checks in the cell wall than T. palustris. In the advanced stages of decay by G. trabeum, the erosions of ray cell walls were identified both in the Korean red pine and radiata pine but $S_3$ layers of tracheid walls were eroded only in the Korean red pine.

• International Journal of Railway
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• v.2 no.3
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• pp.99-106
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• 2009

Checks and tests before putting safety facilities into service as well as the results of these tests are essential, time consuming and may show great variations between each other. Economic constraints and the increasing complexity associated with the development of computerized tools tend to limit the capacity of the classic approval process (manual or automatic). A reduction of the validation cover rate could result in practice. This is not compatible with the French national plan to renew the interlocking systems of the national network. The method and the tool presented in this paper makes it possible to formally validate new computerized systems or evolutions of existing French interlocking systems with real-time functional interpreted Petri nets. The aim of our project is to provide SNCF with a method for the formal validation of French interlocking systems. A formal proof method by assertion, which is applicable to industrial automation equipment such as interlocking systems, and which covers equally the specification and its real software implementation, is presented in this paper. With the proposed method we completely verify that the system follows all safety properties at all times and does not show superfluous conditions: it replaces all the indoor checks (not the outdoor checks). The advantages expected are a significant reduction of testing time and of the related costs, an increase of the test coverage rate, an answer to the new demand of railway infrastructure maintenance engineering to modify and validate computerized interlocking systems. Formal methods mastery by infrastructure engineers are surely a key to prove that more safety is not necessarily more expensive.

• Journal of the Korean Wood Science and Technology
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• v.25 no.4
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• pp.51-60
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• 1997

We investigated the characteristics of air-and vacuum-drying heated by hot plates for 8~14cm-diameter logs or 6~12cm-thick pillars of Pinus koraiensis. And we evaluated the effects of longitudinal kerf and vacuum drying heated by hot plates. The vacuum drying times from green to 10.9~18.6% MC were 15 days, and these times were one-fifth compared to the air-drying times. The longitudinal kerfing had no significant, effect on drying rates during both air-drying and vacuum drying. But drying defects such as surface checks and V-shaped cracks were effectively prevented during air-drying and vacuum drying by longitudinal kerfing. The vacuum drying was more advantageous than air-drying for preventing of surface checks, end checks and V-shaped cracks, and especially, the vacuum dried pillars with longitudinal kerf were almost free from drying defects. In accelerated weathering conditions the resin did not exude for all specimens.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3458-3481
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• 2021

Existing methods for blind identification of linear block codes without a candidate set are mainly built on the Gauss elimination process. However, the fault tolerance will fall short when the intercepted bit error rate (BER) is too high. To address this issue, we apply the reverse algebra approach and propose a novel "two-step-screening" algorithm by solving the linear error equations on the binary Galois field, or GF(2). In the first step, a recursive matrix partition is implemented to solve the system linear error equations where the coefficient matrix is constructed by the full codewords which come from the intercepted noisy bitstream. This process is repeated to derive all those possible parity-checks. In the second step, a check matrix constructed by the intercepted codewords is applied to find the correct parity-checks out of all possible parity-checks solutions. This novel "two-step-screening" algorithm can be used in different codes like Hamming codes, BCH codes, LDPC codes, and quasi-cyclic LDPC codes. The simulation results have shown that it can highly improve the fault tolerance ability compared to the existing Gauss elimination process-based algorithms.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.59-68
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• 2008

This study was carried out to investigate the effects of the Inside end-taping (Inside-ET) and Outside end-taping (Outside-ET) treatments on prevention of drying defects during radiofrequency/vacuum (RF/V) drying domestic yellow poplar log cross section with size of 20~75 mm in thickness and 120~470 mm in diameter. The treatments of Inside-ET and Outside-ET were quite effective for producing sound log cross sections with thinner than 33 mm and smaller than 270 mm in diameter. Even the 60 mm- and 75 mm-thick log cross sections, if the diameter was smaller than 30 cm, it might expect preventing formation of border checks by appropriate end-taping treatments. The positions of the observed border checks differed in diameter ranging at a relative radius about 0.50~0.63 diameter, and it was estimated that it was necessary to select the border position of end-taping treatment properly according to the diameter of log cross sections. It was observed that the radius of 0.3 diameter was the critical location for pretreatment for preventing formation of border checks in the log cross section with middle diameter. There were severe border checks and V-shaped cracks in the log cross section with large diameter. This was because of the severe variation of moisture content along radial direction of natural characteristic of domestic yellow poplar.

• Korean Security Journal
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• no.49
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• pp.157-183
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• 2016

Countries across the globe, including those in Europe, are waging a "war against terrorism" as international terrorist groups such as ISIS and lone-wolf terrorists have unleashed various large-scale attacks on rail infrastructure. Anti-South Korean sentiment exists in Muslim-majority countries because the nation has cooperated with the US for its military interventions in the Middle East, and ISIS has threatened to target South Korea four times since September 9, 2015. In addition, North Korea has been left isolated in the international community with its missile and nuclear tests, while further escalating inter-Korean tension and threatening to strike major facilities and attack important figures in the South. These situations imply that South Korea is no longer immune to terrorist attacks. If the nation fails to prevent or deter such terrorist attacks against rail networks, massive casualties, property damage and social confusion would be unavoidable, deteriorating national and international trust in its counter-terrorism policies. This may lead to a national crisis involving decreases in the number of tourists, dampened interest of foreign investors, and capital flight. This study aims to propose policy measures to enhance railroad security checks, based on the work of railroad police officers, for the sake of protecting citizens and public safety. The suggestions include an incremental expansion of railroad security checks; growth of the railroad police force and adjustment of their policing distribution with other police officers; enhancement of security systems across important rail networks; improvement of the Railroad Safety Act; Southeast Asia, including the corresponding strengthening of the national crackdown illegal immigrants, and plans for pre-emptive and regular cooperation among organizations related to the promotion of security checks and the prevention of terrorist attacks.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.2
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• pp.66-74
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• 2012

Test turnaround time (TAT) is the lead time from reception to reporting. In the complete blood cell count (CBC), 4 units of the XE-2100 (Sysmex Corp., Japan) processed around 80% of quantity, 1 unit of the LH-780 (Beckman-Coulter Incorp., USA) processed around 10% and 1 unit of ADVIA-2120 (Siemens AG, Munich, Germany) processed around 10%. We analyzed the change in the TAT for the CBC for over 7 years, from January of 2005 to December of 2011. The delta check made alterations of delta to WBC, hemoglobin, hematocrit, platelet and metamyelocyte, however, did not made them to band neutrophil, eosinophil, basophil and monocyte. The panic value check made alterations of panic value to hemoglobin, hematocrit, platelet and monocyte. In the criteria of currently slide review, LH-780 and ADVI-2120 analyzers prepared suspect flags of "Blast, Imm NE2, Immature granulocyte, Imm NE1, Left shift, Variant lymphocyte, Atypical lymphocyte, Platelet clumps and NRBC". The New slide review in the XE-2100 analyzer altered the preparations of a smear slide more than a "Platelet clumps flag(${\geq}200unit$), a single flag excluding the "Platelet clumps flag (${\geq}250unit$) and a multiple flag (${\geq}200unit$)". Also, below the 240 unit, medical technologists prepared manual slides selectively according to their evaluations. The automatic reporting rate was 33.4% without alterations, whereas it was 41.0% without alterations, and was thus improved by 7.6%. The slide review rate was 15.2% before using the Q-flag limit, whereas it was 12.1% for a reduce 3.1%. TAT was 45 minutes without the creation alterations of the delta and panic value checks, whereas it was 35 minutes after making alterations of the delta and panic value checks and thus was shortened by 10 minutes. We came to the conclusion that the establishment and operation of delta and panic value checks and slide review criteria suitable for laboratory environment can reduce unnecessary smear slides, re-checking, re-sampling, re-testing, telephone inquiries and concentrated workloads during specific times of the day.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.180-187
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• 2020

Security threats are increasing with interest due to the mass spread of smart devices, and vulnerabilities in developed applications are being exposed while mobile malicious codes are spreading. The government and companies provide various applications for the public, and for reliability and security of applications, security checks are required during application development. In this paper, among the security threats that can occur in the mobile service environment, we set up the vulnerability analysis items to respond to security threats when developing Android-based applications. Based on the set analysis items, vulnerability analysis was performed by examining three applications of public institutions and private companies currently operating as mobile applications. As a result of application security checks used by three public institutions and companies, authority management and open module stability management were well managed. However, it was confirmed that many security vulnerabilities were found in input value verification, outside transmit data management, and data management. It is believed that it will contribute to improving the safety of mobile applications through the case of vulnerability analysis for Android application security.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.2
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• pp.91-105
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• 2014

This paper proposes a digital forensic method by an evaluation function based on timestamp changing patterns. Operations on file or folder leave changed timestamps, which give the ways to know what operations were executed. Changes of timestamps of ten operations of a file and eight operations of a folder were examined. Analyses on the changes on the eight folder operations are newly added in this paper, which are not performed in the previous works. Based on the timestamps changes of the file and the folder, two evaluation functions are proposed. The first evaluation function checks whether timestamps are changed by file and folder operations, and the second evaluation function checks whether timestamps are originated from a source file or other attribute field. By the two output values from these evaluation functions, a digital forensic investigation on the file or the folder is performed. With some cases, i. e. file copy and folder creation operations, the proposed forensic method is tested for its usefulness.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.40-49
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• 1996

In this paper, we studied channel assignment and handover schemes for the indoor microcell systems. For efficient frequency spectrum reuse we proposed the high quality reassignment (HQR) scheme. Proposed HQR scheme tries to keep the reuse distances small by monitoring C/I of channels being used. To assign a channel for a new or handove call, the scheme checks C/I of all available channels. Then HQR assigns the channel that has C/I near the threshold value, A_TH. The scheme also checks C/I of ongoing calls and continuously reassigns a new channel when needed. It attempts handover not only when C/I gets below a handover threshold value, HO_TH, but also when C/I becomes above a high quality reassignment threshold, H_TH. The performance of the proposed HQR scheme was analyzed by a computer simulation configuraed. The performance of the scheme was also analyzed for various threshold values selected and the results are presented in this paper. The results show that HQR scheme perfomrs better than the scheme adopted for DECT.