• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1160-1167
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• 2012

Identifying traffic is an important issue for many networking applications including quality of service, firewall enforcement, and network security. Once we know the purpose of using the traffic in the firewall, we can allow or deny it and provide quality of service, and effective operation in terms of security. However, a number of applications encrypts traffics in order to enhance security or privacy. As a result, effective traffic monitoring is getting more difficult. In this paper, we analyse SSH encrypted traffic and identify differences among SSH tunneling, SFTP, and normal SSH traffics. By using EM clustering, we identify traffics and validate experiment results.

• KAPE Magazine
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• s.207
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• pp.10-11
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• 2013

국내산 오리고기의 차별화를 위해 가금류에 대한 원산지 표시가 의무화 되어 있지만 생산에서 소비까지 품질관리가 업체 자율에 맡겨져 있어 소비자가 믿고 구매할 수 있는 시스템이 아직 미흡한 단계다. 이에 축산물품질평가원에서는 '오리고기 등급판정'을 지난 2011년 11월 21일부터 시범사업으로 시작해 2012년 7월 1일부터 본격적으로 사업을 실시하여 오리고기 제품에 품질등급 및 등급판정일자를 표시토록하고 품질공정관리를 통해 수시 모니터링을 하여 소비자가 안심하고 오리고기를 구입할 수 있도록 하고 있다. 자세한 내용은 지난 10월에서 소개한 바 있다. 그렇다면 우리 식탁에 올라오는 등급판정 받은 오리고기의 등급판정 과정을 어떻게 될까? 이번 11 월호에는 그 과정을 따라가 보자.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.219-226
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• 2019

This study was conducted to understand the overall status of the monitoring program for pesticide residues in foods of South Korea. Further propositions for its improvement were made, and from this study, the status on this program can be summarized as follows. In South Korea, the Ministry of Food and Drug Safety (MFDS) is responsible for overall control of pesticide residue monitoring. Depending on the time of monitoring (sampling at distribution or production step), the government agency responsible for monitoring is different: MFDS, Regional Offices of Food and Drug Safety and local governments are responsible for monitoring of foods at the distribution step, while the National Agricultural Products Quality Management Service (NAQS) and local governments are responsible for monitoring of foods in the production step (partially at sale and distribution steps). According to purpose of monitoring, domestic monitoring programs could be divided into two types: MFDS's "Residue Survey" and NAQS's "National Residue Survey" are conducted mainly for risk assessment purposes and various monitoring programs by the Regional Offices of Food and Drug Safety and local governments are conducted mainly for regulation purposes. For imported foods, monitoring should be conducted at both steps of customs clearance and distribution: the MFDS and the Regional Offices of Food and Drug Safety are responsible for the former, and for the latter, local governments are also responsible. However, it appeared that systematic and consistent monitoring programs are not being conducted for imported foods at the distribution step. Based on the information described above and more detailed information included in this paper, the following proposals for improving the monitoring program were forwarded: i) further clarification of monitoring program purpose, ii) strengthening of the monitoring program for imported foods, iii) providing the public with monitoring results by publication of an annual report and database. It is thought that exhaustive review on the pesticide residue monitoring program and efforts for its improvement are needed in order to assure both food safety and the success of the recently begun positive list system (PLS).

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.298-301
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• 2004

KT는 무궁화 3호 위성을 이용한 양방향 위성 통신 사업을 추진하고 있으며, 지상망을 이용하기 어려운 지역에 정부/공공, 에너지 산업, 기업 단일망 등 다양한 산업 분야를 대상으로 초고속 네트워크를 제공하고 있다. 양방향 위성 통신 서비스는 36,000km 상공의 위성 중계기와 지상 간의 통신 지연을 극복하기 위한 첨단 기술로 운용되고 있으며, 중요 데이터에 대한 위성 통신 품질보증 기능을 제공한다. 본 논문에서는 위성망의 트래픽을 수집하고 데이터를 로깅하는 위성망 트래픽 수집 도구와 수집된 데이터를 마이닝을 통해 실시간 모니터링하고 통계 정보를 생성하는 위성망 패킷 데이터 분석 도구로 이루어진 위성망 패킷 데이터 분석 시스템에 대해 논한다. 위성망 패킷 데이터 분석 시스템은 데이터 송수신 정보를 모니터링 함으로써 실시간 위성 통신 상태를 점검하고, 전송 지연 및 실패 등의 위성 통신 오류 상태를 조기 진단하고 조치할 수 있는 위성망 품질 보증 서비스를 제공한다.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.289-297
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• 2018

The vehicle lubricant has captured 35% of the total lubricant market while the engine oil possessed 77% of the vehicle lubricant market in Korea. The suitable quality management of circulating engine oil is thus required for the driver and engine protection. But, KS and synthetic engine oil products (containing over 30% synthetic oil) are exempt to any quality inspections under Petroleum and Alternative Fuel Business Act. In this study, our research group investigated the quality monitoring of 30 kinds of domestic distributing synthetic engine oils. Two kinds of the engine oil showed an off specification from the test results; one engine oil is an imported and the other is a KS synthetic one. Also, the pattern of engine oils were analyzed using SIMDIST (simulated distillation) and the most engine oils had a broad carbon number spectrum, which is a typical of mineral oils except several imported products. Thus, we concluded that relevant laws for the proper quality management of synthetic oils and KS products are needed to be established for preventing consumer's damages.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.573-588
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• 2009

In this paper, we propose a novel video quality degradation monitoring scheme titled VR-VQMS(Visual Rhythm based Video Quality Monitoring Scheme) over an IPTV service prone to packet losses during network transmission. Proposed scheme quantifies the amount of quality degradation due to packet losses, and can be classified into a RR(reduced-reference) based quality measurement scheme exploiting visual rhythm data of H.264-encoded video frames at a media server and reconstructed ones at an Set-top Box as feature information. Two scenarios, On-line and Off-line VR-VQMS, are proposed as the practical solutions. We define the NPSNR(Networked Peak-to-peak Signal-to-Noise Ratio) modified by the well-known PSNR as a new objective quality metric, and several additional objective and subjective metrics based on it to obtain the statistics on timing, duration, occurrence, and amount of quality degradation. Simulation results show that the proposed method closely approximates the results from 2D video frames and gives good estimation of subjective quality(i.e.,MOS(mean opinion score)) performed by 10 test observers. We expect that the proposed scheme can play a role as a practical solution to monitor the video quality experienced by individual customers in a commercial IPTV service, and be implemented as a small and light agent program running on a resource-limited set-top box.

• Composites Research
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• v.36 no.3
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• pp.186-192
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• 2023

Recently, in the field of railway vehicles, interest in the use of composite materials for weight reduction and transportation efficiency is increasing. Accordingly, research and commercialization development to apply composite materials to various vehicle parts are being actively conducted, and evaluation is conducted centering on post-measurement such as mechanical performance evaluation of finished products to verify quality when composite materials are applied. However, the analysis of heat and stress generated during the molding process of composite materials, which are factors that greatly affect manufacturing quality, is insufficient. Therefore, in this study, in order to verify the molding quality of composite parts for railway vehicles, the molding quality analysis was conducted for the two types of composite interior panels (laminate panel and sandwich panel) that are most actively used. To this end, temperature and strain changes were monitored during the molding process by using an FBG fiber optic sensor, which is easy to apply to the inside of the composite, and the residual strain value generated after molding was completed was measured. As a result, it was confirmed that overheating and excessive residual stress did not occur, thereby verifying the excellent molding quality of the composite interior panel for railway vehicles.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.648-652
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• 1994

Lower Arm은 전차축식 현가장치에 사용되는 자동차부품으로 바퀴에서 발생되는 제동력이나 코너링력 등을 지탱하는 장치이다. V형의 상하 2개의 서스펜션암의 축에 의해 츠레임에 장착되고 좌우에 있는 Lower Arm끝부분은 볼조인트 및 부싱에 의해 스티어링 너클에 부착된다. 압입부품들은 자동차의 주행중 발생하는 외력에 의하여 이탈될 수 있는 위험성에 항상 노출되어 있어 자동차에 사용하는 압입부품들의 이탈력은 매우 중요하지만 한번 이탈시킨 Lower Arm은 이탈력이 현저히 저하되기 때문에 이탈력 측정에 의한 품질관리는 전량검사가 불가능하게 된다. 본 연구는 Lower Arm에 압입되는 볼조인트의 압입력을 압입거리에 따라 측정하여 Lower Arm에 뚫어진 볼조인트 압입구멍의 크기와 압입력의 상관관계를 실험적으로 구할수 있는 크기와 압입력의 상관관계를 실험적으로 구할 수 있는 모니터링 시스템을 개발하고자 한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.960-967
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• 2002

SPC와 EPC의 통합은 연속공정산업에서 성공적으로 사용되고 있다고 널리 인식되어 있다. 그러나, 이산적인 부품 제조공정의 모니터링과 연속 생산공정 모니터링 양쪽 모두를 포함하는 하이브리드(hybrid)산업에서의 이들 기법을 적용하기 위해서는 샘플링비율, 고장감지, 실시간 보정과 공정통제 등에 관한 연구가 필요하다. 본 연구에서는 SPC와 EPCD의 차이를 비교분석하고, 하이브리드 산업에서 SPC와 EPC를 성공적으로 통합하여 제품공정품질관리에 적용하는 사례연구를 제시하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10B
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• pp.936-944
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• 2006

In order to enhance their own customer satisfaction index that is one of the top level managerial performance indices, Internet communication service providers endeavor onto establishing a total quality management system. Specifically, it is under discussion that some critical Internet communication network quality characteristics closely related to customer satisfaction index should be controlled aiming to this managerial goal. This paper presents an application scheme of I-MR control charts for monitoring Internet communication network quality characteristics. This statistical quality control scheme generates a signal to practitioners when it detects the network quality characteristics out-of control. It is designed based on; 1) individual measurements; and 2) moving ranges between two consecutive individual measurements collected with a constant time interval. Empirical analyses are illustrated to estimate the expected quality improvement ratios that can be realized with the application scheme proposed in this paper. Assuming that the assignable causes can be revealed and eradicated, regarding two Internet communication services A, B, seven network quality characteristics for each service, eleven distinct measuring spots for each network quality characteristic, the expected quality improvement ratios are calculated with which the effect of the application scheme is evaluated. Results show the ranges of the expected quality improvement ratios; 1) Service A, (1) mean (0.31%-11.44%), (2) standard deviation (9.82%-71.10%): 2) Service B, (1) mean (0.29%-17.64%), (2) standard deviation (8.05%-60.59%). Hence, It is anticipated that the I-MR control charts based application scheme can be effective not only to improving the mean and dispersion of the network quality characteristics concerned but also to maintaining the network quality characteristics in-control consequently.