천공지 유리 피판술을 이용한 소아 사지 연부조직 결손의 재건

김학수,김경철,김성언,Kim, Hak-Soo,Kim, Kyung-Chul,Kim, Seong-Eon 대한미세수술학회 2007 Archives of reconstructive microsurgery Vol.16 No.1

Perforator free flap (PFF) is currently a major reconstructive option for soft tissue reconstruction in adults. Although PFFs have been used commonly, most reconstructive surgeons still hesitate to perform PFFs in children. The main cause of concern is the perceived high failure rate related to the small diameter of children's perforator vessels. We present 8 consecutive cases of successful transfer of thoracodorsal artery (TDA) & anterolateral thigh (ALT) perforator flap in children. Between 2003 and 2005, 8 children(4 to 13 years old) with soft tissue defects of the extremities were reconstructed with TDA & ALT PFFs. All flaps completely survived. There were no problems relating to vascular spasm or occlusion. Range of motion of reconstructed extremities were fully recovered. Among 8 patients, only 1 patient was performed an additional flap thinning procedure. 8 cases of TDA & ALT perforator flaps were successfully transferred in children. PFF is an excellent option in reconstruction of children as well as in adults because of its thinness, long pedicle length, least donor site morbidity and acceptable donor site scar.

컨트롤 흐름 경로 기반의 비즈니스 프로세스 타당성 검증 기법

김학수,박찬희,설주영,손진현,Kim, Hak-Soo,Park, Chan-Hee,Sul, Joo-Young,Son, Jin-Hyun 한국정보처리학회 2007 정보처리학회논문지D Vol.14 No.5

과거에 비해 최근에는 비즈니스 프로세스가 복잡해짐에 따라 비즈니스 프로세스를 디자인할 때 발생할 수 있는 문제점이 점차 증가하고 있다. 그러나 비즈니스 프로세스 검증의 중요성이 높아지고 있지만 많은 검증 방법이 제안되고 있지 않은 실정이다. 한편, 최근 BPMI에서 주도하는 BPMN은 비즈니스 프로세스를 위한 표준화된 그래픽 표기법으로써 BPMN을 지원하는 디자인 툴을 이용하면 다양하고 복잡한 프로세스 환경을 쉽게 디자인하고 분석할 수 있다. 본 논문에서는 이러한 BPMN으로 디자인할 때 발생한 수 있는 문제점들을 효율적으로 검증할 수 있는 몇 가지 검증기법을 제시한다. 이로 인해 비즈니스 프로세스 실행 시 발생할 수 있는 에러들을 사전에 검증하여 예기치 못한 큰 비용을 줄일 수 있다. As the current trend in e-business has led to more various and complex business processes in recent years, problems in business process models have increased gradually. Accordingly, the concern to validation of business process models has been much larger but there are few validation checking mechanisms supported so far. On the other hand BPMN driven by BPMI is a standard graphical notation. Using the tool supporting BPMN, business process can be modeled graphically and analyzed easily. In this paper, we present technical mechanisms which can efficiently detect anomalies in a process composed of BPMN and are capable of avoiding higher unexpected costs during runtime.

용액상에서 합성된 ZnO 입자의 생성과정에 관한 연구

김학수,김동환,Kim Hak-Soo,Kim Donghwan 한국재료학회 2005 한국재료학회지 Vol.15 No.10

We studied the possibility of $Zn_4O(Ac)_2(OH)$ formation as a precursor for ZnO nano particles in sol-gel method. Four different additives such as tetra methyl ammonium hydroxide, mono ethanol amine (MEA), LiOH, and $H_2O$ were used for zinc acetate dissolved in 2-methoxy ethanol. ZnO particles of 5-6 nm in size were observed. Existence of $Zn_4O(Ac)_6$ was not verified. $Zn_4O(Ac)_2(OH)$ molecules were observed and they were believed to be the precursors of ZnO. A peak at 275nm in UV-Vis analysis was observed In the case of MEA and $H_2O$ but no ZnO particles were detected in transmission electron microscopy.

깨물근을 통한 하악골 관절돌기하부골절의 관혈적 정복 및 내고정술

김학수,김성언,Kim, Hak-Soo,Kim, Seong-Eun 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.2

Purpose: Surgical approaches to the condylar neck and subcondyle area can cause some morbidity such as, facial nerve injury, time-consuming nature and external scar etc. So many surgeons hesitate using open reduction and internal fixation for the treatment of subcondylar fractures. We report open reduction and internal fixation of subcondylar fractures in 13 adult patients via transmasseteric approach. Methods: From 2007 to 2009, 13 adults with subcondylar fracture of mandible were treated with open reduction and internal fixation via transmasseteric approach. A preauricular incision was extended downwards in a curvilinear fashion in the cervicomastoid skin crease. Skin flap was elevated above the SMAS layer. Masseter muscle was splitted at the anteroinferior edge of the parotid gland. After the fracture was reduced, fixed with appropriate plates and screws. All operation were performed under general anesthesia. Results: Mean follow-up period was 13.3 months. There were no signs and symptoms of facial nerve injury, difficulty in mouth opening, or malocclusion. Dissection time was roughly within 30 minutes. Conclusion: Transmasseteric open reduction and internal fixation of mandible subcondylar fracture can be performed with excellent visualization, and inconspicuous scar. It also offers swift access to the subcondylar area while substatially reducing the risk to the facial nerve and eliminating the complications associated with transparotid approaches.

황화 CoMo / γ- Al2O3 촉매상에서 수첨탈질반응과 수첨탈산소 반응에 상호작용

김학수,박해경,김경림 ( Hak Soo Kim,Hea Kyung Park,Kyung Lim Kim ) 한국공업화학회 1991 공업화학 Vol.2 No.2

황화 CoMo/γ-Al_2O_3 촉매를 사용하여 473-723 K의 온도와 10∼l5×10^5 Pa의 압력 그리고 접촉시간 0.0125-0.03 g-cat hr/ml-feed 범위에서 pyridine 의 수첨탈질반응과 m-cresol의 수첨탈산소 반응의 상호작용 및 그 속도론에 관하여 연구하였다. Pyridine의 수첨탈질반응과 m-cresol의 수첨탈산소반응은 서로 상호반응을 저지 억제하였으며, pyridine에 의한 m-cresol의 수첨탈산소반응의 억제효과는 m-cresol에 의한 pyridine의 수첨탈질반응의 억제효과보다 더 컸으나 반응성은 m-cresol이 더 높았다. Pyridine의 수첨탈질반응 속도식 및 m-cresol의 수첨탈산소반응 속도식을 LHHW 모델을 이용하여 구한 결과 γ_(HDN) =k_(HDN)·K_PC_P/(1+K_CC_C+K_PC_P) , γ_(HDO) =k_(HDO)·K_CC_C/(1+K_CC_C+K_PC_P) 였다. 각 온도에서 반응속도 상수 및 흡착평형상수를 구하여 Arrhenius plot과 Van`t Hoff plot을 행하여 구한 활성화 에너지값은 pyridine과 m-cresol이 각각 16.21Kcal/mole,13.83Kcayl/mole이었고, 흡착열은 각각 -6.458Kcal/mole, -5.045Kcal/mole이었다. Interactions between pyridine hydrodenitrogenation (HDN) and m-cresol hydrodeoxygenation (HDO), and the kinetic analysis were studied over sulfided CoMo/γ-Al_2O_3 catalyst at the range of temperatures between 473 K and 723 K, the total pressures between lO×10^5 Pa and 50×10^5 Pa, and the contact times between 0.0125 g-cat. hr/ml-feed and 0.03g-cat. hr/ml-feed. HDN of pyridine and HDO of m-cresol were inhibited by each other and the inhibition effect of HDO by pyridine is higher than that of HDN by m-cresol. But reactivity of m-cresol is higher than that of pyridine. The rate equations of pyridine and m-cresol were given to be γ_(HDN) =k_(HDN)·K_PC_P/(1+K_CC_C+K_PC_P) and γ_(HDO) =k_(HDO)·K_CC_C/(1+K_CC_C+K_PC_P) in terms of Langmuir-Hinshellwood-Hougen-Watson model. At each temperature, reaction rate constants and adsorption equilibrium constants were determined and the activation energies of pyridine HDN and m-cresol HDO are 16.21 and 13.83 ㎉/mol, respectively and the heat of adsorptions are -6.458 and -5.045 ㎉/mole, respectively.

전자전달증대기를 이용한 고효율 태양전지 시스템에서 전자전달증대기 입력 교류 전압 변화에 따른 태양전지 효율 향상에 대한 연구

김학수,유영기,이혁,윤소영,Kim, Hak Soo,Ryu, Young Kee,Lee, Hyuk,Yun, So Young 한국진공학회 2013 Applied Science and Convergence Technology Vol.22 No.3

In this paper, we would like to introduce Electron Relay Enhancer (ERE), a supplementary device, which improves commercial solar cell efficiency minimizing electron-hole recombination of solar cell. The ERE in this study is mainly composed of two capacitors which are connected to AC power source and bridge diode system which controls electron flow direction. Two capacitors repeat collecting electrons from solar cell and pumping the collected electrons to load resistance or inverter through the bridge diode system. While one positively charged capacitor collect electrons, the other negatively charged one pumps electrons. A positively charged capacitor pulls the more exited electrons from the solar cell, before the exited electrons recombine the holes in solar cell. That is why the ERE system enhances solar cell efficiency. As a result, the measured power increase of the solar cell with the ERE is varied from 5.9 W to 25.6 W in each experimental condition. Maximal increase rate of the solar cell power with ERE is 30.8% of solar cell power without ERE. 본 연구에서는 기존의 상업용 태양전지에서 전자-정공 재결합을 최소화하여 태양전지의 효율을 향상시키는 부가장치인 전자전달증대기(Electron Relay Enhancer: ERE)를 소개한다. 전자전달증대기는 교류 전력 공급 장치와 연결된 두 개의 캐패시터와 전자의 흐름 방향을 제어하는 브릿지 다이오드 시스템으로 구성되어 있다. 두 개의 캐패시터는 브릿지 다이오드 시스템을 통하여 태양전지로부터 전자를 포집하고 포집된 전자를 로드저항이나 인버터쪽으로 펌핑하는 것을 반복한다. 양으로 대전된 한 개의 캐패시터가 전자를 포집하는 동안 음으로 대전된 다른 캐패시터는 전자를 펌핑한다. 태양전지에서 여기된 전자가 정공에 재결합되기 전에 양으로 대전된 캐패시터는 태양전지로부터 더 많은 여기된 전자를 끌어온다. 이러한 까닭에 ERE 시스템은 태양전지의 효율을 증대시킨다. 연구결과로 ERE 활성 시 태양전지의 증가된 전력은 각각의 실험조건에서 5.9 W에서 25.6 W사이였고, 가장 높은 태양전지전력증가율은 ERE 비활성 시 태양전지 전력의 30.8%였다.

Flow Characteristics Evaluation in Reactor Coolant System for Full System Decontamination of Kori-1 Nuclear Power Plant

김학수,김초롱,Kim, Hak Soo,Kim, Cho-Rong Korean Radioactive Waste Society 2018 방사성폐기물학회지 Vol.16 No.3

The Kori-1 Nuclear Power Plant (NPP), WH 2-Loop Pressurized Water Reactor (PWR) operated for approximately 40 years in Korea, was permanently ceased on June 18, 2017. To reduce worker exposure to radiation by reducing the dose rate in the system before starting main decommissioning activities, the permanently ceased Kori-1 NPP will be subjected to full system decontamination. Generally, the range of system decontamination includes Reactor Pressure Vessels (RPV), Pressurizer (PZR), Steam Generators (SG), Chemical & Volume Control System (CVCS), Residual Heat Removal System (RHRS), and Reactor Coolant System (RCS) piping. In order to decontaminate these systems and equipment in an effective manner, it is necessary to evaluate the influence of the flow characteristics in the RCS during the decontamination period. There are various methods of providing circulating flow rate to the system decontamination. In this paper, the flow characteristics in Kori-1 NPP reactor coolant according to RHR pump operation were evaluated. The evaluation results showed that system decontamination using an RHR pump was not effective at decontamination due first to impurities deposited in piping and equipment, and second to the extreme flow unbalance in the RCS caused deposition of impurities.

XML 구조 문맥을 사용한 효율적인 경로 표현식 조인 알고리즘

김학수,신영재,황진호,이승미,손진현,Kim, Hak-Soo,Shin, Young-Jae,Hwang, Jin-Ho,Lee, Seung-Mi,Son, Jin-Hyun 한국정보처리학회 2007 정보처리학회논문지D Vol.14 No.6

XML 데이터 검객을 위한 표준 질의 언어로서 XQuery와 XPath가 W3C에 의해 표준으로 제정되었다. XQuery와 XPath를 보편적으로 사용함에 따라, 최근 연구는 방대한 XML 데이터베이스에서 XPath 경고 표현식에 대한 효율적인 질의 처리를 위한 데이터 구조 및 알고리즘 개발에 초점을 두고 있다. 최근에, XPath 경로 표현식을 처리할 때 XML 엘리먼트 사이의 구조적 관계(조상-자손, 부모-자식)를 결정하는 구조적 조인의 개념은 중요한 XPath 프로세싱 기법중의 하나가 되었다. 그러나 XPath 질의 처리에서 자주 발생하는 구조적 조인들은 높은 비용을 요구한다. 본 논문에서, 우리는 XPath 질의들을 효율적으로 처리하기 위해 제안한 구조적 인덱스(SI) 기반의 새로운 구조적 조인 알고리즘(SISJ)을 제안한다. 실험 결과에서는 이전의 알고리즘보다 근소하게 더 효율적인 성능을 보여 준다. 그러나 재귀성이 높은 문서에 대해서는 제안기법의 가지치기 특성으로 인해 약 30% 이상의 성능향상을 보였다. As a standard query language to search XML data, XQuery and XPath were proposed by W3C. By widely using XQuery and XPath languages, recent researches focus on the development of query processing algorithm and data structure for efficiently processing XML query with the enormous XML database system. Recently, when processing XML path expressions, the concept of the structural join which may determine the structural relationship between XML elements, e.g., ancestor-descendant or parent-child, has been one of the dominant XPath processing mechanisms. However, structural joins which frequently occur in XPath query processing require high cost. In this paper, we propose a new structural join algorithm, called SISJ, based on our structured index, called SI, in order to process XPath queries efficiently. Experimental results show that our algorithm performs marginally better than previous ones. However, in the case of high recursive documents, it performed more than 30% by the pruning feature of the proposed method.

한국 언론변동 이론을 향하여

김학수(Hak Soo Kim) 한국사회이론학회 1985 사회이론 Vol.- No.1

신구콘크리트 접합면의 인장강도 특성

김학수 ( Kim Hak-soo ),양인환 ( Yang In-hwan ),조서경 ( Cho Seo-kyung ) 한국구조물진단유지관리공학회 2001 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.5 No.2

The construction methods of precast prestressed concrete beam bridges have been proposed recently. The properties of flexural tensile strength between precast prestressed concrete beam and cast-in-place concrete is the important factor that affects the structural performance of PSC beam bridges. This paper aims at evaluating the tensile strength between old and new concrete. Tensile strength gain with age after placing new concrete was evaluated. Test results show that the tensile strength between old and new concrete is much smaller than that of monolithic concrete. Also, it is shown that the curing condition of concrete has the effect on tensile strength.