• Macromolecular Research
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• v.13 no.3
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• pp.229-235
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• 2005

Various alkoxyamine initiators for nitroxide mediated radical polymerization (NMRP) were prepared in high yields by a simple substitution reaction of nitroxide anions with benzyl bromide. The required nitroxide anions were easily generated by treating either nitroxide free radicals or hydroxy amine with an alkali metal such as sodium or potassium in THF. This method is both practical and efficient, since the ionic conditions prevent other side reactions from occurring, such as the self-coupling or oligomerization reactions that are observed in the case of radical trapping conditions. To demonstrate the utility of the resulting alkoxyamine initiators, end- and telechelic-alkoxyamine PEG macroinitiators derived from the alkoxyamines were synthesized by a simple chemical modification, and used for the preparation of PEG-b-PS and PS-b-PEG-b-PS block copolymers by NMRP.

• Annals of Clinical Neurophysiology
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• v.8 no.1
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• pp.102-105
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• 2006

We present a case with stepwise weakness and sensory involvement of both hands for more than 2 months. His nerve conduction study findings revealed prolonged terminal latencies, decreased motor and sensory conduction velocities and conduction blocks of both ulnar nerves, more severely on left side. And there were other abnormalities manifested with mononeuropathy multiplex. Increased cerebrospinal fluid protein was found. We diagnosed him as Lewis-Sumner syndrome and tried high dose oral steroid therapy for 2 months. He showed improvement of motor functioning with persistent conduction block.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.189-197
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• 2009

This paper suggests the system for searching and application is to be in combination between existing hair art area and Image/Video processing area. This proposed system usually saves various hair types into a database, then, users send images of their face over the internet by using WebCam. Finally, they can find the hair types for users. Hair cutting is technology that form draft to make hair style. Man cut must decide how in image of sinciput, image of side bean curd, after lower image must operate. Silhouette is produced as is different by change of this three places. Customer increases in the beauty salon and beauty salon chain being changed, research about beauty art is necessary point of time. In this treatise, our country of when swim and operate haircut about problem that happen sample survey and analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.163-165
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• 2016

AES-128 블록 암호에 대해 상관관계 전력분석 공격을 통해 비밀키를 추출할 수 있는 보안공격 시스템의 프로토타입을 개발했다. Verilog HDL로 모델링된 AES-128 암호 코어의 RTL 시뮬레이션을 통해 switching activity 정보를 추출하고, 이를 PowerArtist 툴을 이용하여 순시 전력을 도출하였다. 추출된 순시 전력으로부터 출력 레지스터의 hamming Weight 모델링과 상관관계 분석을 통해 128 비트의 비밀키 중 일부를 획득하는 보안공격 시스템을 개발하였다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1230-1232
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• 2000

To reduce harmonics in the AC line and achieve a unit power factor, A 4 paralled single phase PWM AC/DC converter has been proposed. In this paper, the coupling components are derived analytically from PWM converter input transformer model and control scheme to solve this problem is proposed. Unit power factor was obtained and the AC-side current harmonics were reduced. Simulation results show the usefulness of the proposed method and applicability to PWM converter in auxiliary block of high speed train.

• Journal of Chest Surgery
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• v.21 no.4
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• pp.748-756
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• 1988

Transaortic closure of ventricular septal defect, suturing a patch on the morphological right ventricular side in patients with congenitally corrected transposition of great arteries might help to avoid postoperative complete heart block if the aorta is large and the subaortic conus is not well developed. In two patients[aged 6 and 16 years] with congenitally corrected transposition of great arteries, ventricular septal defect, and pulmonary stenosis, transaortic closure of ventricular septal defect was performed. No postoperative complete heart block resulted. One hospital death occurred because of sepsis who had underwent reoperation due to bleeding from the aortotomy site. Minimal aortic regurgitation developed in another patient.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.241-242
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• 2019

This technology is a water leak repair technology using composite materials of concrete structures that block leakage of structures by injecting rapid microcement into the face of underground concrete to block water and injecting flexible glycidylacrylate. Rapid micro cement system repair materials are mixed with fine fibers to improve the flexural sensitivity of the material and to form a layer that blocks stabilized water at the back of the structure by allowing rapid and tight spatial filling during injection with high cohesion The glycidylacrylate repair material can control the expansion rate, and the external stress also has the characteristic that the form of the material is not destroyed or separated, which can also be applied to vibrating induced structures that produce repetitive fatigue loads, and has an effective durability in saline, alkali, acid (chloric acid, sulfuric acid, nitric acid).

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.3
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• pp.217-226
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• 2022

Background: Intraosseous anesthesia is the process by which an anesthetic solution, after penetration of the cortical bone, is directly injected into the spongiosa of the alveolar bone supporting the tooth. This study aimed to compare the effectiveness of the traditional inferior alveolar nerve block (IANB) and computerized intraosseous anesthesia in the surgical extraction of impacted lower third molars, compare their side effects systemically by monitoring heart rate, and assess patients' a posteriori preference of one technique over the other. Methods: Thirty-nine patients with bilaterally impacted third molars participated in this study. Each patient in the sample was both a case and control, where the conventional technique was randomly assigned to one side (group 1) and the alternative method to the contralateral side (group 2). Results: The traditional technique was faster in execution than anesthesia delivered via electronic syringe, which took 3 min to be administered. However, it was necessary to wait for an average of 6 ± 4 min from the execution to achieve the onset of IANB, while the latency of intraosseous anesthesia was zero. Vincent's sign and lingual nerve anesthesia occurred in 100% of cases in group 1. In group 2, Vincent's sign was recorded in 13% of cases and lingual anesthesia in four cases. The average duration of the perceived anesthetic effect was 192 ± 68 min in group 1 and 127 ± 75 min in group 2 (P < 0.001). The difference between the heart rate of group 1 and group 2 was statistically significant. During infiltration in group 1, heartbeat frequency increased by 5 ± 13 beats per minute, while in group 2, it increased by 22 ± 10 beats per minute (P < 0.001). No postoperative complications were reported for either technique. Patients showed a preference of 67% for the alternative technique and 20% for the traditional, and 13% of patients were indifferent. Conclusion: The results identified intraosseous anesthesia as a valid alternative to conventional anesthesia in impacted lower third molar extraction.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.61-67
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• 2001

Background: Usually, lumbar epidural block is performed on the $L_{3-4}$ interspace. This study was designed to evaluate the analgesic efficacy and shortening of labor duration comparing the $L_{1-2}$ and $L_{3-4}$ interspace epidural blocks in nulliparous normal vaginal deliveries and then investigates side effects following the blocks. Methods: Eighty healthy nulliparous women were divided into two groups, $L_{1-2}$ (n = 40) and $L_{3-4}$ (n = 40). Epidural blocks, lumbar epidural block were performed at the $L_{1-2}$ and $L_{3-4}$ interspace with a catheter advancing 3 cm cephalad. The initial dose of 12 ml (0.167% bupivacaine, fentanyl $50{\mu}g$ and clonidine $75{\mu}g$) was injected epidurally at 4 cm dilatation of cervix and severe pain of labor. If a visual analogue scale (VAS) score was more than 4 points, an additional dose was administered epidurally using the same volume as the above mentioned, but with the exception that the bupivacaine was diluted to 0.1 percentage. The maternal blood pressure, pulse rate, respiration rate and fetal heart rate were measured at 10 min intervals for the first 30 min, at 15 min interval for the next 30 min and at 30 min interval for the last one hour following the blocks. The duration of the first (active) and second stages of labor was counted and the neonatal Apgar score was recorded at one and five min after delivery. The degree of motor block, pruritus, nausea and vomiting were also noted. Results: The patients in group $L_{1-2}$ had lower pain scores than group $L_{3-4}$ at 5, 20, 30, 60 mins. The duration of 1st and 2nd labor stage in the $L_{3-4}$ epidural block were $272{\pm}33.5$ min, $49.2{\pm}27.4$ min respectively but those in the $L_{1-2}$ epidural block were $253.5{\pm}32.5$ min, $37.3{\pm}22.3$ min, respectively. Conclusions: We concluded the analgesic efficacy and shortening of labor duration in $L_{1-2}$ epidural block was better than those in $L_{3-4}$ epidural block. Maternal hemodynamic change, motor block. pruritus, nausea, vomiting and Apgar score showed no significant differences between the two groups.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.383-393
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• 2010

DVC (Distributed Video Coding) allows us to explore the video statistics at the decoder side, resulting in a less complex encoder and more complex decoder. In this approach, it is important to generate a good prediction to the current Wyner-Ziv frame, called side information, which plays a crucial role in the overall performance of a DVC system. Conventional MCFI (motion compensated frame interpolation) techniques, which explore temporal correlations between neighbor frames of the current frame, preform the block-based or object-based motion estimation, but, they do not include the basis frame for the Wyner-Ziv frame. This paper proposes an efficient way to get better side information, by finding the average frame between neighbor frames and by comparing adaptively the candidate blocks. Through computer simulations, it is shown that the proposed method can improve the performance up to 0.4dB and provide better subjective and objective visual qualities in Wyner-Ziv CODEC.