• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.5-15
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• 2007

Objective: The purpose of this study was to evaluate the mechanical performance of mini-screws during insertion into artificial bone with use of the driving torque tester (Biomaterials Korea, Seoul, Korea), as well as testing of Pull-out Strength (POS). Methods: Experimental bone blocks with different cortical bone thickness were used as specimens. Three modules of commercially available drill-free type mini-screws (Type A; pure cylindrical type, Biomaterials Korea, Seoul, Korea, Type B; partially cylindrical type, Jeil Medical, Seoul, Korea, Type C; combination type of cylindrical and tapered portions, Ortholution, Seoul, Korea), were used. Results: Difference in the cortical bone thickness had little effect on the maximum insertion torque (MIT) in Type A mini-screws. But in Type B and C, MIT increased as the cortical bone thickness Increased. MIT of Type C was highest in all situations, then Type B and Type A in order. Type C showed lower POS than Type A or B in all situations. There were statistically significant correlations between cortical bone thickness and MIT, and POS for each type of the mini-screws. Conclusion: Since different screw designs showed different insertion torques with increases in cortical bone thickness, the best suitable screw design should be selected according to the different cortical thicknesses at the implant sites.

• The KIPS Transactions:PartA
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• v.15A no.3
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• pp.181-188
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• 2008

Nowadays, most web sites are developed using dynamic web pages where web pages are generated and transmitted by web application programs. Therefore, the ratio of attacks injecting malevolent strings to vulnerable web applications is increasing. In this paper, we present a static program analyzer which analyzes whether a web application program has vulnerabilities to the SQL injection attack and the cross site scripting(XSS) attack. To analyze programs using abstract interpretation framework, we designed an abstract domain which models potential string set along with excluded strings and developed an abstract interpreter for the PHP language. Also, based on them, we implemented a static analyzer. According to our experiments, our analyzer has competitive analysis speed and accuracy compared with related research results.

• The korean journal of orthodontics
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• v.31 no.3 s.86
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• pp.325-333
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• 2001

Optimal orthodontic treatment could be possible when a orthodontist can predict and control tooth movement by applying a planned force system to the dentition. The moment to force(M/F) ratio at the bracket, has been shown to be a primary determinate of the pattern of tooth movement. As various n/F ratios are applied to the bracket on the tooth crown, strain distribution in periodontium can be changed, and the center of rotation in tooth movement can be determined. It is, therefore, so important in clinicalorthodontics to know the strain distribution in a force system of a M/F ratio. The purpose of this study was to analyze the strain distribution in orthodontic force system by strain gauge attached to tooth root, and to evaluate the usage of the method. For this study, an experimental upper anterior arch model was constructed, where upper central incisors, on the root surface of which, 8 strain gauges were attached, were implanted In the photoelastic resin, as in the case of 4mm midline diastema. Three types of closing of upper midline diastema closure were compared : 1. with elastomeric chain(100g force) in no arch wire, 2. elastomeric chain in .016“ round steel wire, 3. elastomeric chain in .016”x.022“ rectangular steel wire. The results were as follows. 1. Strain distributions on labial, lingual, mesial and distal root surface of tooth were able to be evaluated with the strain gauge method, and the patterns of tooth rotation were understood by presuming the location of moment arm. 2. Extrusion and tipping movement of tooth was seen in closing in no arch wire, and intrusion and bodily movement was seen with steel arch wire inserted.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.951-952
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• 2011

발전소에 설치된 대용량 발전기는 고정자 권선을 지지하기 위해 축 방향으로 삽입된 슬롯 Wedge의 지지압력이 느슨해지면 절연파괴와 같은 각종 사고가 발생할 수 있다. 이를 예방하기 위해 주기적으로 Wedge 조임 상태를 점검하고 있으나 그동안 작업자의 손가락 감각으로 평가하던 방법을 가속도 진동 센서를 이용하여 주파수 스펙트럼을 분석함으로써 발전기 고정자 Wedge 조임 상태를 객관적으로 판정할 수 있도록 방법을 고안하였다.

• Journal of the Korean Magnetics Society
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• v.14 no.1
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• pp.29-32
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• 2004

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.114-117
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• 2000

일반적으로 LPA에서는 위상을 조정하기 위해 매우 긴 지연선을 필요로 한다. 지연성능은 고전력이나 저전력 모두에서 임의의 길이의 동축선로를 여러번의 과정을 거쳐 적용해봄으로써 구현된다. 그러나 동축선로형 지연선은 부피나 높은 삽입손실 등의 제약이 많이 따른다. 본 논문에서는 마이크로스트립 형태의 지연선 대역통과 여파기를 설계하였고, 실험결과는 지연선여파기가 동축선로를 대신하여 LPA 시스템에 적용이 가능함을 보였다.

• Clinical and Experimental Pediatrics
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• v.45 no.9
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• pp.1120-1125
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• 2002

Purpose : Percutaneous cannulation of the central vein in children and infants may be technically difficult and can cause serious complications. There are many techniques to improve the success rate and to decrease the complications in central vein cannulation. This study was undertaken to determine whether audible Doppler guidance can help operators improve the results of central vein cannultion in pediatric ICU. Methods : A total of 46 central vein cannulations were performed using audible Doppler guidance technique. Using an 8-MHz Doppler ultrasound device(Pocket-Dop II. iMex. USA), the artery and the vein were identified by their characteristic Doppler sounds. Results : There was a total of 46 patients with 20 boys and 26 girls, respectively. The mean age was $3years{\pm}45months$(range : 1-156 months). The number of infants was 18 and the mean age was $6.3{\pm}3.8$ months(range : 1-12 months). The most common site of central vein cannulation was the right internal jugular vein(63%). The cannulation was successful in 44 out of 46 procedures(96%). The success rate at the first attempt was 59% with 48% in the patients who had the history of previous cannulation and 70% in the patients who did not, respectively. The success rate in infants was 94%(17 out of 18). The average access time was $5.2{\pm}8.3$ minutes in children contrary to $7.5{\pm}10.3$ minutes in infants. There were no serious complications, but six patients had complications including four hematoma, one arterial puncture, and one pneumothorax. Conclusion : This central vein cannulation using Doppler guidance may improve the success rate of central vein cannulation and decrease the development of serious complications in infants and children.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.619-624
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• 1992

Tn5 lac 삽입으로 채소입고병원균에 길항력이 약화된 T-67 및 고추역병균과 참깨역병균에 길항력이 약화된 T-81의 Tn5 lac 유전자 일부와 오른쪽 말단에 있는 길항관련 유전자의 flanking sequence가 cloning된 pAG67 및 pAG81 clone을 선발하였고, pAG67 및 pAG81 clone된 길항관련 유전자의 flanking sequence를 야생 길항균 Pseudomonas maltophilia B-14의 DNA를 probe로 사용하여 Southern hybridization으로 확인하였으며, 제한효소 지도를 작성하여 8Kb 및 4Kb 크기의 flanking sequence가 cloning되었음을 확인하였다. pAG6 및 pAG81의 flanking sequence를 EcoRi-BglII와 EcoRI-MpaI으로 분리하여 유전자 은행으로부터 길항관련 유전자가 cloning된 cosmid clone 7개주를 선발하였다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.252-256
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• 2001

본 논문에서는 IMT-2000 기지국용 2단 저잡음 증폭기를 설계했다. 잡음지수 특성이 뛰어난 HP사의 PHEMT 소자인 ATF-35143을 사용하였고 능동소자의 바이어스는 $V_{ds}$ 가 3 v $I_{d}$을 30mA로 설정했다. 첫 단은 최소잡음 지수에 중점을 두고 설계했고 둘째 단은 이득에 초점을 맞추어 설계했다. 입출력 정재파 비를 줄이기 위해서 전체증폭기의 앞단과 뒷단에 삽입손실이 0.2dB인 X503 SMT 90도 하이브리드 커플러를 설치 했다. 제작을 위해 기판은 두께 0.76mm이고 비유전율 4.2의 FR-4를 사용했다. 설계된 저잡음 증폭기의 특성은 주파수대역 1.92GHz～1.98GHz에서 잡음지수 0.45dB, 입출력 정재파 비 1.2이하, 이득은 32dB이상의 특성을 보였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.2
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• pp.40-46
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• 1998

In order to achieve high flexibility in manufacture, chip control is one of the most serious problems at present. The continuous type chip (uncontrolled chip), which interrupts the normal cutting process and damages the operator, tool and workpiece have a higher force ratio. while the controlled chip which is 6 or 9 type and C type, has the values of the force ratio below 0.6 The chips were classified by 4 types. in chip formation and by described chip history during the cutting process. Finally, the feasibility of utilizing force ratios in chip control will be pointed out while comparing generated force signals during the cutting process.