3분 및 4분 상완골근위부 골절에서의 외반형 및 내반형에 따른 임상적 비교

최창혁,권굉우,김신근,이상욱,신동규,이승진 대한골절학회 2002 대한골절학회지 Vol.15 No.4

목 적 : 수술적으로 치료한 3분, 4분 상완골 근위부 골절을 외반형과 내반형으로 재분류하여 임상적 결과를 비교하고자 하였다. 대상 및 방법 : Neer 분류상 3분, 4분 상완골근위부 골절로 분류된 21례에 대해 수술적 치료를 시행하고 12개월 이상 추시된 증례를 대상으로, 골절부위의 각형성, 상완골두의 방향성, 그리고 우세 전위결절의 양상에 따라 외반형과 내반형으로 재분류하여 UCLA shoulder rating scale에 따른 기능적 평가를 시행하였다. 결 과 : 단순 방사선 소견을 기준으로 Neer의 3, 4분 상완골 근위부골절을 외반형과 내반형 및 각각의 아형(subtype)으로 분류할 수 있었다. 견관절 반치환술을 시술한 2례를 제외하고 분석한 각 그룹의 UCLA 기능적 평가는 외반형에서 양호 이상의 결과가 9례중 8례(89%), 내반형에서 10례중 4례(40%)로 외반형에서 더 우수한 임상적 경과를 보였다. 결 론 : 상완골 근위부 골절에서 골두의 방향성은 골절의 각형성 및 우세 전위결절의 양상과 높은 상관관계를 가졌으며, 내반형의 경우 혈행과 신경장애가 좀더 빈번하고 예후도 불량한 것으로 나타났고, 이러한 경우 수술시 도달 방법, 연부조직 상태에 대한 평가가 더욱 신중하게 고려되어야 할 것으로 생각되었다. Purpose : We reclassified three-and four-part proximal humerus fracture by Neer's classification into valgus & varus type, and compared the results of these groups. Materials & methods : 21 cases classified as three- and four-part fracture in Neer's classifiation were treated surgically and followed for 12 months. We reclassified the 21 cases vlagus and varus type fractures, according to angulation of fractures, facing of humeral head, and dominant displaced tuberosity. Functional evaluation was done by UCLA shoulder rating scale. Results : Neer's three- and four-part proximal humerus fractures could be reclassified based on angulation, facing of humeral head, and dominant tuberosity displacement. The functional results according to UCLA shoulder rating scale were good or excellent in 8 of 9 cases of valgus type(89%), and at 4 in cases of varus type(40%). The clinical result of the valgus type was better than that of the varus type. Conclusion : Based on reclassification system of proximal humerus fractures, clinical results and radiographic findings including angulation, facing of head and domonant tuberosity displacement showed close relationship. Neurovascular complication were more frequent in the varus type. Therefore, careful evaluation including surgical approach and soft tissue status should be considered in the varus type of complex proximal humerus fracture.

골수강내 금속정 및 나사못 맞물림을 이용한 경골의 치료

최창혁,권굉우,김신근,이상욱,강창진 대구효성카톨릭대학교 1997 연구논문집 Vol.56 No.2

Fracture of the tibial shaft is the most common among the long bone fractures, and it is difficult to treat because of a high incidence of delayed union, nonunion and malunion. Interlocking Intramedullary mailing is considered to be valuable method in treating long bone fracture such as tibial fracture these days because it enables rigid fixation, early joint motion exercise and weight bearing. Between April 1993 and March 1997, we treated 63 cases of tibia fractures with interlocking intramedullary nailing. The results were as follows: 1. Among the 63 cases, 51 cases were closed fractures and 12 cases were open fractures. 2. Static interlocking nailing was done in all cases and dynamization was done in 7 cases in postoperative 13 weeks. 3. Average union time was 19.9 weeks, 19 weeks with closed tibia fracture and 2.4 weeks with open tibia fracture. According to fracture site, 22 weeks with proximal tibia fracture, 19.2 weeks with mid-tibia fracture and 21.4 weeks with distal tibia fracture. According to the Winquist-Hansen classification, Type I was 19.8 weeks, Type Ⅱ was 20.4 weeks, Type Ⅲ was 22 weeks and Type Ⅳ was 26 weeks. 4. Weight bearing was started at the time of subsidence of pain and tenderness of the fracture site, 11.5 weeks with closed fracture and 12.3 weeks with open fracture. 5. According to the functional result of Klemm and Borner, 44 cases were excellent, 9 cases were good, 7 cases were fair and 3 cases were poor.

FET형 반도체센서 및 시스템 개발

손병기,조진호,최평,박이순,서화일,권대혁,고광락 경북대학교 센서기술연구소 1996 연차보고서 Vol.1996 No.-

기존의 센서들의 난점을 극복할 수 있는 새로운 형태의 FET형 전해질(electrolyte :H^+, K^+, Ca^2+, Na^+)센서소자 및 분석 시스템의 개발을 중점적으로 추진하였으며, FET형 포도당센서 및 압력센서의 개별 FET형 센서에 관한 연구도 병행하였다. FET형 전해질센서를 이용한 휴대용 전해질 측정기와 desktop형 4채널 전해질 분석기를 제작하였다. 또한 이 시스템을 소형화하기 위한 주문형 아날로그-디지탈 변환기 내장형 CMOS 프로세서를 설계하고 검증하였다. The main object of this research is to develope a new FET type electrolyte(H^+, K^+, Ca^2+, Na^+) sensors and analysis system which can overcome the problems of the conventional sensors. Parallel researches on FET type sensors such as glucose and pressure humidity are also in progress. A portable electrolyte meter and desktop 4-channel electrolyte analysis system is fabricated. A customized CMOS processor with built-in analog-to-digital converter is designed and verified.

Efficient Publication Method of XML data on Peer-to-Peer Environments

Hyuk Jin Ko,Woojun Kang 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

As XML is becoming a standard for information representation and exchange on the Web, the functionality enabling a secure and efficient publication of XML is necessarily demanded. Especially, these trends are more outstanding in distributed heterogeneous environment such as Peer-to-Peer(P2P) environments. Although some studies have tries to make efficient distribution with center-oriented administration approaches, it is difficult for them to adapt directly to P2P environments which have inherently the characteristics of dynamic participation. Our main idea is that using the authorization policy of access control, authentication verification conditions are evaluated not by terms of the predefined authentication policy, but by terms of the subject credential information involved in authorization policy, which make it possible to adapt the enormous incoming of subject to the network. We propose a novel publication method with authorization policy for efficient publication of XML data.

Oral Presentation : Treatment of intrabony defects using guided tissue regeneration: case series

( Hyuk Jin Ko ),( Jae Mok Lee ),( Jo Young Suh ),( Jin Woo Park ) 대한치주과학회 2010 대한치주과학회 학술대회자료집 Vol.2010 No.1

Risk Factors Associated with Poor Outcomes in Patients with Brain Abscesses

Ko, Seok-Jin,Park, Kyung-Jae,Park, Dong-Hyuk,Kang, Shin-Hyuk,Park, Jung-Yul,Chung, Yong-Gu The Korean Neurosurgical Society 2014 Journal of Korean neurosurgical society Vol.56 No.1

Objective : The purpose of this study was to describe the clinical characteristics, treatment outcomes, and prognostic factors in patients with brain abscesses treated in a single institute during a recent 10-year period. Methods : Fifty-one patients with brain abscesses who underwent navigation-assisted abscess aspiration with antibiotic treatment were included in this study. Variable parameters were collected from the patients' medical records and radiological data. A comparison was made between patients with favorable [Glasgow Outcome Scale (GOS) ${\geq}4$] and unfavorable (GOS <4) outcomes at discharge. Additionally, we investigated the factors influencing the duration of antibiotic administration. Results : The study included 41 male and 10 female patients with a mean age of 53 years. At admission, 42 patients (82%) showed either clear or mildly disturbed consciousness (GCS ${\geq}13$) and 24 patients (47%) had predisposing factors. The offending microorganisms were identified in 25 patients (49%), and Streptococcus species were the most commonly isolated bacteria (27%). The mean duration of antibiotic administration was 42 days. At discharge, 41 patients had a favorable outcome and 10 had an unfavorable outcome including 8 deaths. The decreased level of consciousness (GCS <13) on admission was likely associated with an unfavorable outcome (p=0.052), and initial hyperglycemia (${\geq}140mg/dL$) was an independent risk factor for prolonged antibiotic therapy (p=0.032). Conclusion : We found that the level of consciousness at admission was associated with treatment outcomes in patients with brain abscesses. Furthermore, initial hyperglycemia was closely related to the long-term use of antibiotic agents.

Esthetic treatment of gingival melanin hyperpigmentation with a Nd:YAG laser and high speed rotary instrument: comparative case report

Ko, Hyuk-Jin,Park, Jin-Woo,Suh, Jo-Young,Lee, Jae-Mok Korean Academy of Periodontology 2010 Journal of Periodontal & Implant Science Vol.40 No.4

Purpose: The purpose of this study was to evaluate the clinical effectiveness of and patient's satisfaction with treatment of gingival melanin hyperpigmentation with a Nd:YAG laser and a high speed rotary instrument. Methods: Three patients with melanin hyperpigmentation in the anterior parts of the gingiva were chosen for this case study. Clinical photographs were taken at the preoperative state and three patients were treated under local anesthesia. In the maxilla, the gingival deepithelization was conducted with a high speed diamond bur, whereas, in the mandible with a Nd:YAG laser. Clinical photographs were taken immediately after the procedures and at the 1st, 2nd, and 4th week to evaluate clinical color changes. A week after the procedure, the patients filled out a questionnaire about any pain or discomfort. At the 4th week after the procedure, the patients filled out questionnaires about esthetic aspects of the results of treatment. Results: In all cases, both anterior gingival areas were depigmented with satisfaction and the patients did not complain of severe pain or discomfort. At the 1st week of healing, the gingiva showed moderate to fast epithelization. Two weeks after the procedure, clinically, the gingiva showed almost complete healing. Four weeks after the procedure, there was significant improvement in gingival melanin hyperpigmentation. Conclusions: The Nd:YAG laser and the high speed rotary instruments seem to be effective for the esthetic treatment of gingival melanin hyperpigmentation.

신용회복제도의 도덕적 해이 유발가능성에 관한 실증연구

고혁진 ( Hyuk Jin Ko ),박영석 ( Young S. Park ),이재현 ( Jae Hyun Lee ) 한국금융학회 2008 금융연구 Vol.22 No.4

신용회복제도는 개인파산자에게 소비유연화의 기능을 제공하고 과도한 채무상환의 부담을 덜어줌으로써 금융소외자들이 정상적인 경제활동을 가능하게 하는 사회안전망의 기능을 수행한다. 반면 신용회복제도는 채무자의 상환노력을 낮추어 도덕적 해이를 유발할 것이라는 우려도 있다. 본 연구는 과거 국내에 시행된 3개의 주용 신용회복제도가 채무자의 도덕적 해이를 유발하는가에 대한 실증분석을 수행하였다. 본 연구에서는 모 전업카드사의 신용카드 사용자의 자료를 이용하여 3개 신용회복제도 발표일을 사건일로 하는 사건연구를 수행하였다. 대부분의 국외의 선행연구에 따르면 신용회복제도는 채무자들의 자발적 파산수요를 늘린다는 결과를 제시하면서 도덕적 해이에 대한 우려를 나타냈다. 그러나 본 연구의 결과에 따르면 일부그룹의 도덕적해이의 개연성이 나타나기는 했지만 전체적으로 신용회복제도가 도덕적해이를 유발한다는 유의한 결과는 관찰되지 않았다. 이러한 결과를 통해 국내의 채무자들의 도적적해이가 없다고 단정할 수 없다. 국외의 연구는 연체율이 급증한 시점에서 이루어진 결과이고, 본 연구의 분석기간은 연체율이 하락하는 시점에서 수행되었기 때문에 나타난 결과일 수 있다. When the credit recovery plan offers big advantages such as delays in repayment of debts and exemption of interests, debtors with moral hazard will not make repayments but intend to take benefits from the plan. As consumers with such a behavior increase, the society will have to bear the massive economic losses. In this sense, the plan is controversial due to the possibility to stimulate moral hazard. The plan does not always give benefits to its applicants. Applicants for the plan have to take disadvantages as their information is submitted and strictly managed by all financial organizations. In addition, they have to bear the direct expenses including the legal counseling fee for application, and the indirect expenses of losing social reputations. Accordingly, introduction of the plan is not always regarded as a stimulator of voluntary defaults. The plan should be considered from the long-term perspective and in the context of the national economy, since the plan serves as the social safety net allowing financially isolated citizens to normally make economic activities again. Most of the previous literatures, studied mostly in the US, found the empirical evidence that the plan increased voluntary defaults demand, and expressed concerns over moral hazard of delinquents. This study aims to verify whether the credit recovery plan, which has been introduced or being introduced in Korea, has increased the number of delinquent cardholders. For this, we compared the three cases before and after introducing the plan specified in <Table 1>, in order to verify the influences of the plan on the voluntary delinquency demand. As classified in Chapter 2, the three cases included the work-out plan for multiple debtors (announced in July 2002), the overall rescue programs for credit delinquents (announced in March 2004), and the credit recovery plan for financial delinquents with low income (announced in March 2005), and the cases were analyzed based on the announced month. Using logistic regression model, we control other factors influencing the delinquency rate used in Min et al.(2007) and Gross-Souleles (2002), and add the dummy variable implying the plan enforcement (Six months before the introduction: 0, and six months after the introduction: 1). If the introduction of the plan increases voluntary delinquents, the coefficient of dummy variables will show a significant positive value. Also, we analyzed the influences of the plan on voluntary delinquents with the differences between the estimated delinquency rate and the actual delinquency rate. This approach was added to improve robustness of the results of the formula (3.1). First, I excluded dummy variables and calculated the estimated delinquency rate through the logistic regression model. I calculated the difference between the estimated delinquency rate and the actual delinquency rate, and then verified the hypothesis by finding out the significance of the difference. As empirical data for the study, we used data of a large Korean credit card company. Not all applications for the plan are resulted from the use of credit cards. However, most of studies including major researches on the plan such as the one of Fay, Hurst, and White (2002), and the one of Gross and Souleles (2002) depended on data of credit card users. In addition, according to the surveys in Korea, 67.3% of respondents answered that credit card debts resulted in application for the credit recovery plan, proving that the credit card data is representative. In this study, credit card users were classified into three grades to analyze the influences of the plan on each group of users. According to the credit rating, users from grade one to grade four were classified as "High grade Users," those from grade five to grade six as "Potential group," and those in grade seven as "Marginal group." The finance limit utilization rate was used for detailed classification of groups. Those of grade five or higher show the utilizatio

Peer-to- Peer 네트워크 상에서 XML 데이터의 효율적이고 안전한 배포 방식에 관한 연구

고혁진(Ko, Hyuk-Jin),강우준(Kang, Woo-Jun) 한국산학기술학회 2007 한국산학기술학회논문지 Vol.8 No.3

XML이 인터넷 상에서 수많은 정보의 표현과 교환의 표준으로 자리매김해감에, XML 데이터를 안전하고 효율적으로 배포하기 위한 방법의 강구가 강력히 요구 되는 추세이다. 특히 Peer-to-Peer 같은 환경에서 그런 경향은 더욱 두드러지고 있다. 지금까지의 SDI 연구는 user profiling 에 대해 새로 입수되는 XML source에 대한 match (filtering 문제)에 관련된 문제에 집중, 효율적 배포와 관련된 연구가 드문 실정이며, 효율적 배포에 관련된 소수의 기존연구에서도 중앙집중식 관리방식을 사용함으로써 Peer-to-Peer와 은 분산환경에는 바로 적용시키기가 어렵다. 본 논문에서는 이러한 특징을 가지고 있는Peer-to-Peer 환경에서 인가정책과 비밀분산을 이용함으로써 안전하고 확장이 용이한 XML 데이터의 배포 방법을 제안한다. As XML is becoming a standard for representation and exchange of abundant information on the Web, solutions for a secure and selective dissemination of XML data, known as SDI, are strongly demanded. Such trends are more outstanding especially in distributed heterogeneous environment such as Peer-to-Peer. Although many approaches have been proposed to provide secure and efficient SDI mechanisms, almost previous approaches have focused only on filtering with user profile and they adopt center-oriented administration approaches. It is therefore difficult to adapt them directly to the distributed Peer-to-Peer environments characterized by dynamic participation. In this paper, we develop a novel dissemination method, which makesuse of authorization policy and secret sharing scheme. It provides more secure, scalable means for XML dissemination on Peer-to-Peer networks.

신용카드의 적정한도와 가계의 채무불이행에 관한 연구

고혁진 ( Hyuk Jin Ko ),박영석 ( Young S. Park ),위경우 ( Kyeong Woo Wee ),이재현 ( Jae Hyun Lee ) 한국금융학회 2009 금융연구 Vol.23 No.3

신용카드사는 주로 한도관리를 통하여 카드사용자의 채무불이행을 통제한다. 카드사의 입장에서는 한도를 적게 부여하는 것이 잠재적 채무불이행금액을 줄이는데 유리하지만, 카드사용금액이 줄어들어 카드사의 이익을 줄이는 방향으로 영향을 미칠 수 있다. 또한 한도의 증가는 재무적곤경에 처한 카드사용자에게 유동성을 제공하며, 이후 카드사용자의 현금흐름이 개선되면 카드사용자는 채무불이행을 극복하게 된다. 따라서 카드사의 입장에서는 부정적 효과와 긍정적 효과의 상충관계를 고려하여 사용자의 속성에 맞는 적정한도를 찾아내고 이를 기준으로 한도를 부여하는 것이 중요하다. 여기서 적정한도란 카드사용자의 위험속성에 부합하는 한도를 의미한다. 본 연구에서는 카드사용자를 신용등급으로 분류하여 각 계좌의 시점별 적정한도를 추정하여 초과한도(부족한도)를 추정하였고 초과한도가 채무불이행 패턴에 미치는 영향을 분석하였다. 실증 결과 전체적으로 초과한도는 연체를 줄이는 방향으로 영향을 미쳤다. 세부적으로 초과한도는 연체빈도, 연체금액과는 음의관계를, 생존기간과는 양의관계를 나타냈다. 물론 그룹별로 차이가 존재하고 있으나, 이러한 효과는 흥미롭게도 신용도가 낮은 그룹에서 크게 나타났다는 것이다. 최근 국내의 가계채무의 급증은 경기침체 심화에 따른 기대소득의 감소 그리고 대출이자율의 상승과 맞물려 한계가계의 추가자금조달의 필요성을 증가시키기고 있다. 본 연구는 가계자금조달에서 신용한도와 채무불이행과의 관계를 분석한 연구라는 점에서 시의성이 높을 것으로 판단된다. In general, credit card companies control card holders` default by managing their credit limits. It is advantageous for card companies to impose smaller limits to reduce the amount of potential default; however, it may also reduce profits of card companies resulted from downsized card using amount. Besides, the increase of credit limits would provide liquidity to card holders who are in financial distress, serving as a positive platform later for card users to overcome default problem with their improved cash flow. Hence it would be critical for card companies to figure out fair credit limits for each user and impose proper limits coincident with card users` attribute after considering both positive and negative effects of adjusting credit limits. Here, the fair credit limit refers to the one that is in line with the risk attribute of a card user. This study classified card users based on their credit rating and estimated excess limits (deficient limits) after evaluating fair credit limits of each account at a each time. Furthermore, the impact of excess limit on the delinquency patterns was also analyzed in this study. The specific procedure of analysis is as follows: ① After card users were classified into groups based on their risk attribute, the average limits of each group were calculated, and the results were regarded as fair credit limits. ② Excessive limits (deficient limits) were calculated after subtracting average limits from actual limits of each group. ③ Pure excess limits (pure deficient limits) were calculated after the effect of other factors that might influence the excessive limits (deficient limits) calculated in ② was controlled. ④ The impact of pure excessive limits (pure deficient limits) on default was analyzed. Here are the results of the analysis. First, let`s take a look at the impact of each group`s excess limits on delinquency. Overall, pure excessive limits had a negative relation with delinquency, so pure excessive limits contributed to reducing delinquency, influencing positively. The pure excess limits in total limits reduced delinquency in groups with relatively good credit ratings and the pure excessive limits in financial service limits decreased delinquency in groups with bad credit ratings. The relation between excess limits and frequency of delinquency is as follows. As predicted, excess limits had a negative correlation with the frequency of delinquency. In other words, as accounts got more excessive limits on average during the survival length, the accounts underwent less delinquency. The survival length had a positive correlation with excessive limits in all groups. A notable point is that excessive limits in financial service of the grade1 had a negative correlation with the survival length. It is hard to interpret this relation because the grade1 is the one with excellent credit rating. The fact that the best credit group experienced delinquency even with excessive limits could be interpreted as some uncontrollable adverse events happened to the card users. It might be difficult to prolong the survival length by just increasing credit limits to a certain degree. Next, let`s take a look at the impact of excess limits on the delinquent amount in each group. The delinquent amount is important in that it influences the profit and loss of card companies directly. One of the reasons that caused the credit card crisis in 2003 was the excess credit limits given to users, so positive coefficient, in general, was expected. However, it turned out that excluding the grade 4 and 5, the excess limits had a negative relation with the delinquent amount. In particular, the grade 6 that took up most of the delinquent amount with bad credit ratings had a negative relation and the coefficient was the lowest, which is quite notable. Therefore, it is needed for credit card companies to increase the credit limits to a certain level for users with grade6 in an effort to reduce the delinquency amount. Meanwhile, this study also analyzed panel data analysis(fixed effect model) in addition to using pooled OLS method in an attempt to substantiate the result of research further. Also, an analysis using the 2SLS model was added to control endogeneity with pure excess line ratio of previous month as an instrumental variable. As a result, the coefficient varied slightly, but the same signs and significance consistent to those in the pooled OLS came out. Thus, the result of this study is judged to be reliable. Recently, the surge of household debt has led households in marginal state to need more funds, which is also influenced by the rise of loan rates and decrease of expected income stemmed from deepened economic slow-down. According to the result of this study, positive effect of excess limits, which is providing more buffer to financially distressed households to overcome default based on provided liquidity, is bigger than negative effects, which is increasing the default amount. Yet, it should be noted that providing liquidity to users with long-term financial difficulty will make the potential default amount bigger. This study is judged to be timely and proper in that it analyzed the relation between the credit limit and default in household finance, which hasn`t been studied in depth so far.