• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.515-528
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• 2020

Underground concrete structures are usually designed to be used for decades, but in recent years, many of them are nearing their original life expectancy. As a result, it is necessary to promptly inspect and repair the structure, since it can cause lost of fundamental functions and bring unexpected problems. Therefore, personnel-based inspections and repairs have been underway for maintenance of underground structures, but nowadays, objective inspection technologies have been actively developed through the fusion of deep learning and image process. In particular, various researches have been conducted on developing a concrete crack detection algorithm based on supervised learning. Most of these studies requires a large amount of image data, especially, label images. In order to secure those images, it takes a lot of time and labor in reality. To resolve this problem, we introduce a method to increase the accuracy of crack area detection, improved by 0.25% on average by applying adversarial learning in this paper. The adversarial learning consists of a segmentation neural network and a discriminator neural network, and it is an algorithm that improves recognition performance by generating a virtual label image in a competitive structure. In this study, an efficient deep neural network learning method was proposed using this method, and it is expected to be used for accurate crack detection in the future.

• Journal of the Korean Arthroscopy Society
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• v.6 no.1
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• pp.37-42
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• 2002

Purpose : The purpose of this study was to evaluate the results of arthroscopic meniscal repair according to joint stability. Materials and Methods : Twenty cases were reviewed, which had underwent arthroscopic meniscal repair. The mean age was 32.3 years old. The mean follow-up period was 59.7 months. Menisci that had underwent complete repair of associated ligament injuries (8cases, Sa) and menisci that had no associated ligament injury (9 cases, Sb) were classified as stable group (S), and the others (3 cases) as unstable group (U). Also stable group was divided into acute and chronic group. The result was evaluated with Lysholm score and IKDC method. The statistical analysis was done using Wilcoxon rank sum test and Fisher's exact test (p<0.05). Results : Group Sa had $87.5\%$ satisfactory and Lysholm score was 90.9. Group U had $66.7\%$ satisfactory, and Lysholm score was 77.7. Group Sb had $89.9\%$, satisfactory and Lysholm store was 91.4. In acute group $91.7\%$ was satisfactory, Lysholm score 92.5, in chronic group $80\%$ was satisfactory, Lysholm score 88.6. Conclusion : Joint stability was important factor for the outcome of meniscal repairs. So, it is desirable to repair meniscus injury early and the repair of associated ligament injuries should be performed together.

• Korean Journal of Cognitive Science
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• v.4 no.1
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• pp.177-212
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• 1993

My research is based on the parser for ill-formed input by Mellish in a paper in ACL 27th meeting Proceedings. 1989. My system is composed of two parsers:WFCP and IFCP. When WFCP fails to give the parse tree for the input sentence, the sentence is identified as ill-formed and is parsed by IFCP for error detection and recovery at the syntactic level. My system is indendent of grammatical rules. It does not take into account semantic ill-formedness. My system uses a grammar composed of 25 context-free rules. My system consistes of two major parsing strategies:top-down expection and bottem-up satisfaction. With top-down expectation. rules are retrieved under the inference condition and expaned by inactive arcs. When doing bottom-up parsing. my parser used two modes:Left-Right parsing and Right-to-Left parsing. My system repairs errors sucessfully when the input contains an omitted word or an unknown word substitued for a valid word. Left- corner and right-corner errors are more easily detected and repaired than ill-formed senteces where the error is in teh middle. The deviance note. with repair details, is kept in new inactive arcs which are generated by the error correction procedure. The implementation of my system is quite different from Mellish's. When rules are invoked. my system invokes all rules with minimal inference. My bottom up parsing strategy uses Left-to-Right mode and Right-to-Left mode. My system is bottom-up-parsing-oriented like the chart parser. Errors are repaired in two ways:using top-down hypothesis, and using Need-Chart which keeps the information of expectation and complection of expanded goals by rules. To reduce the number of top-down cycles. all rules are invoked simultaneously and this invocation information is kept in Need-Chart. This idea will be extended for the implementation of multiple error recovery system.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.225-231
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• 2017

Objective : Solid bone fusion is an essential process in spinal stabilization surgery. Recently, as several minimally invasive spinal surgeries have developed, a need of artificial bone substitutes such as demineralized bone matrix (DBM), has arisen. We investigated the in vivo bone growth rate of DBM as a bone void filler compared to a local autologous bone grafts. Methods : From April 2014 to August 2015, 20 patients with a one or two-level spinal stenosis were included. A posterior lumbar interbody fusion using two cages and pedicle screw fixation was performed for every patient, and each cage was packed with autologous local bone and DBM. Clinical outcomes were assessed using the Numeric Rating Scale (NRS) of leg pain and back pain and the Korean Oswestry Disability Index (K-ODI). Clinical outcome parameters and range of motion (ROM) of the operated level were collected preoperatively and at 3 months, 6 months, and 1 year postoperatively. Computed tomography was performed 1 year after fusion surgery and bone growth of the autologous bone grafts and DBM were analyzed by ImageJ software. Results : Eighteen patients completed 1 year of follow-up, including 10 men and 8 women, and the mean age was 56.4 (32-71). The operated level ranged from L3/4 to L5/S1. Eleven patients had single level and 7 patients had two-level repairs. The mean back pain NRS improved from 4.61 to 2.78 (p=0.003) and the leg pain NRS improved from 6.89 to 2.39 (p<0.001). The mean K-ODI score also improved from 27.33 to 13.83 (p<0.001). The ROM decreased below 2.0 degrees at the 3-month assessment, and remained less than 2 degrees through the 1 year postoperative assessment. Every local autologous bone graft and DBM packed cage showed bone bridge formation. On the quantitative analysis of bone growth, the autologous bone grafts showed significantly higher bone growth compared to DBM on both coronal and sagittal images (p<0.001 and p=0.028, respectively). Osteoporotic patients showed less bone growth on sagittal images. Conclusion : Though DBM alone can induce favorable bone bridging in lumbar interbody fusion, it is still inferior to autologous bone grafts. Therefore, DBM is recommended as a bone graft extender rather than bone void filler, particularly in patients with osteoporosis.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.6
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• pp.510-515
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• 2016

Recently, corrosion occurred on the piles of a marine bridge located on the NamHae expressway in Korea. A sacrificial anode cathodic protection system was installed to prevent corrosion damage in the marine bridge. In the case of the marine bridge in this study, the sacrificial anode cathodic protection system was applied at the tidal and splash zones of the piles because the upper part of the structure was not corroded, and because corrosion occurs at the tidal and splash zones due to sea tides. To verify the performance of the sacrificial anode cathodic protection system 8 years later, cathodic protection (CP) current, CP potential, and degree of depolarization were measured. The experimental results on the performance of the sacrificial anode cathodic protection system from a total of 60 piles were classified into 4 categories: good CP effect results (13 piles), partial CP effect results (27 piles), temporarily erroneous results (5 piles), and need for maintenance because of delamination (15 piles). It was determined that additional repairs are required, such as the application of bulk anodes and jacket casings, for piles where the CP effect is poor.

• Journal of Korean Orthopaedic Sports Medicine
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• v.12 no.1
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• pp.24-28
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• 2013

Purpose: All-inside meniscal repair using FasT-Fix (Smith & Nephew Endoscopy, Andover, Massachusetts, USA) is a popular method for the meniscal tear. However, there was no report after all-inside repair using FasT-Fix for the meniscal tear in Korea. Therefore, the purpose of this retrospective study was to report clinical outcomes after all-inside meniscal repair using FasT-Fix. Materials and Methods: 25 consecutive patients underwent meniscal repairs using FasT-Fix for tears of the posterior horn of the medial or lateral menisci combined with hamstring anterior cruciate ligament (ACL) reconstructions. Postoperative evaluations included Lysholm knee score and Tegner activity scale. Using clinical criteria, a repaired meniscus was considered healed if there was no effusion or joint line tenderness, negative McMurray test, and no sense of giving way. Results: The average follow-up was 47.9 months (range, 40 to 61 months). At follow-up, the mean Lysholm score was 91.8 and the mean Tegner activity scale was 5.6. According to clinical criteria, 20 (80%) menisci was healed, and 5 (20%) failed. Conclusion: All-inside meniscal repair using FasT-Fix showed satisfactory results in patients with hamstring ACL reconstructions.

• Archives of Plastic Surgery
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• v.37 no.1
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• pp.59-66
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• 2010

Purpose: In the finger, there are three major palmar arches in the arterial system. The location of this arches are constant. The middle and distal transverse arches are consistently large (almost 1 mm) and may be used for arterial vessel repairs either proximally or distally, depending on the length and direction needed. This paper describes our experiences in reconstruction and replantation of the finger using rerouting the transverse digital palmar arch. Methods: 31 patients with injuries according to our classification were treated from March of 2005 to October of 2008. In this study the authors subdivided injuries into those with amputation distal to the insertion of the flexor digitorum profundus (Class I, 31 fingers); those with amputation distal to the insertion of the flexor digitorum superficialis (Class II, 4 fingers). Replantation was performed using the artery-only technique with neither vein nor nerve repair. Because the artery has been damaged, it is still possible to make a direct suture by transposing the arterial arch in an inverted Y to I arterial configuration or converting the arch. Venous drainage was provided by an external bleeding method with partial nail excision, medical leech, and repaired margin. Results: The success rate was 87% (n=27) in class I and 75% (n=4) in class II. The authors conclude that crushing and complete avulsion injuries & amputations are salvageable, with acceptable functional results in select patients, especially those with amputation distal to the insertion of the flexor digitorum superficialis. Conclusion: We performed replantation and reconstruction with only-arterial transposing anastomosis successfully, resulting in good recovery of aesthetic and functional outcome. Three major digital palmar arches, especially distal two branches, give us additional treatment options. In the finger replantation and reconstructive techniques using rerouting healthy the transverse digital palmar arch increase the survival rate of the finger.

• Journal of the Korean Society of Food Culture
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• v.17 no.5
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• pp.578-583
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• 2002

The purposes of this study were to a) find out the operational characteristics of the contract-managed highschool foodservice in Seoul, b) investigate the expected level of meal-price and facilities investment cost perceived by contract-managed highschool foodservice managers c) compare the present level and expected level of meal-price and facilities investment cost. From October 12 to November 13 in 2001, the questionnaires were mailed to 249 high schools which was managed by contract foodservice company with respondent rate 40.2%. Data were analyzed using SPSS Win(10.0) for descriptive analysis and one group paired t-test. The results of this study were as follows ; 1. The student enrollment of highschools run by contract-managed foodservice was 1,243 with 72.6% participation rate of school lunch program. The average meal-price was 2,138 won. The average annual period of school foodservice operation was 156.78 days per year. The average contracting period was about 3 years. 2. The average cost concerned in the facilities investment amounts 169,578,180 won at the initial investment and 25,204,092 won at the repairs and maintenance cost in the course of operation. 3. The present level of meal-price and facilities investment cost were respectively 2,136won/meal and 171,157,336.72 won. And expected level of meal-price and amount of facilities investment cost were 2,418.75 won and 121,353,215.19 won. Comparing the present level with the expected level of the meal- price and facilities investment cost, expected level of meal-price was significantly higher than the present level of meal-price(p<.001) and expected level of facilities investment cost was significantly lower than present level of facilities investment cost(p<.001).

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.77-88
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• 2006

The maintenance / repair of concrete pavements has become an issue as a result of increasing of concrete pavements' service year. Asphalt overlay is applied to the concrete pavements after partial repairs on all occasions. This thesis discusses the application standard, evenness, skid resistance, noise, economical efficiency, extension of life span, etc. of diamond grinding, a method of maintenance about concrete pavements. Based on this, it was applied to the field and measured the performance. It was measured the longitudinal evenness of before and after the construction through measurement equipment. and surveyed the skid resistance the each lane classified using the SN standard value. In case of noise, it is selected the kind of vehicle, velocity, then measured the noise between control and constructed site. In addition, it is evaluated the average texture depth. As a result of the analysis, longitudinal evenness is improved about $6{\sim}40%$, skid resistance is improved 66% at first section,37% at second section. Noise is reduced 3.4dB average, and average texture depth is 79% deeper than control section. Therefore, it can be concluded that diamond grinding is suitable as maintenance / repair method of concrete pavements.

• Analytical Science and Technology
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• v.25 no.5
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• pp.324-332
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• 2012

Construction era of Pungnabtoseong earthen wall is one of the most popular controversial issues in Korean archaeological research. For the evaluation of construction era, OSL dating was carried out using seven pottery pieces collected in each construction stage. From TL/OSL characteristics, and the results of absolute zeroing test and recovery test, it was proved that the pottery samples were completely bleached. The reliable paleodose was evaluated by using the SAR method with preheat at $220^{\circ}C$, and the pottery OSL age was determined from the ratio of paleodose to annual dose rate. Considering the resultant OSL ages, archaeological context and the related 14C ages, the first construction era was determined as $294{\pm}52$ yrs AD ($1{\sigma}$ SE). Also we found that the enlargement of construction stage III was $328{\pm}30$ yrs AD ($1{\sigma}$ SE) and final construction was finished within $400{\pm}76$ yrs AD ($1{\sigma}$ SE). Therefore, it is suggested that the construction of Pungnabtoseong earthen wall was firstly started in the late $3^{rd}$ century AD and several enlargements and repairs had been carried out, before the transfer of the capital of Baekje dynasty to Woongjin (Gongju) at 475 AD.