정상면역을 가진 성인에서 발생한 식도 방선균증

김현수 ( Hyun Soo Kim ),천종운 ( Jong Woon Cheon ),김민수 ( Min Su Kim ),정창길 ( Chang Kil Jung ),김경록 ( Kyung Rok Kim ),최재원 ( Jae Won Choi ),강동우 ( Dong Woo Kang ),김선영 ( Sun Young Kim ) 대한소화기학회 2013 대한소화기학회지 Vol.61 No.2

Hyun Soo Kim, Jong Woon Cheon, Min Su Kim, Chang Kil Jung, Kyung Rok Kim, Jae Won Choi, Dong Woo Kang and Sun Young Kim1 Departments of Internal Medicine and Pathology1, DongKang Medical Center, Ulsan, Korea Actinomycosis is a chronic suppurative disease and caused by Actinomycosis species, principally Actinomyces israelii, which are part of the normal inhabitant on the mucous membrane of the oropharynx, gastrointestinal tract, and urogenital tract. It usually affects cervicofacial, thoracic and abdominal tissue. Cervicofacial type has the highest percentage of occurrence with 50%. Actinomycosis frequently occurs following dental extraction, jaw surgery, chronic infection or poor oral hygiene. It may also be considered as an opportunistic infection in immunocompromised patients such as malignancy, human immunodeficiency virus infection, diabetes mellitus, steroid usage or alcoholism. But, actinomycosis rarely occurs in adults with normal immunity and rare in the esophagus. We report an unusual case of esophageal actinomycosis which was developed in a patient with normal immunity and improved by therapy with intravenous penicillin G followed oral amoxicillin, and we also reviewed the associated literature.

스카이브릿지 설치위치에 따른 고층건물의 진동제어 성능평가

김현수,박용구,고현,이의현,이동근,Kim, Hyun-Su,Park, Yong-Koo,Ko, Hyun,Lee, Ui-Hyun,Lee, Dong-Guen 한국공간구조학회 2010 한국공간구조학회지 Vol.10 No.3

In this study, the vibration control effect according to the installation location of the sky-bridge and the difference of natural periods of the connected buildings has been investigated. To this end, 40-story and 50-story building structures connected by a sky-bridge were used as example structures and the equivalent modeling method was used. Boundary nonlinear time history analyses were performed using El Centro and Taft earthquakes to investigate the dynamic behavior of the example structures and vibration control effect of the sky-bridge. Based on numerical results, it has been shown that displacement responses can be effectively controlled as the installation floor of the sky-bridge increases and acceleration responses can be effectively reduced when the sky-bridge is installed on the mid-stories of the example building. 본 연구에서는 스카이브릿지 설치위치 및 연결된 구조물의 고유진동주기 차이에 따른 전체 구조물의 진동제어 효과를 분석하였다. 이를 위하여 스카이브릿지로 연결된 40층과 50층 구조물을 예제 구조물로 사용하였고, 등가모형화기법을 이용하여 예제 모델을 구성하였다. El Centro 및 Taft 지진을 사용하여 경계비선형 시간이력해석을 수행하였고 구조물의 동적거동과 진동제어 효과를 분석하였다. 해석결과 변위응답은 스카이브릿지를 상부층에 설치할수록 더 효과적으로 제어할 수 있었고 가속도응답은 구조물의 중간층부근에 설치할 때 더 효과적으로 저감시킬 수 있었다.

Rat periodontal ligament cell에서의 RANKL mRNA의 발현

김현수,정현주,김영준,김옥수,Kim, Hyun-Soo,Chung, Hyun-Ju,Kim, Young-Joon,Kim, Ok-Su 대한치주과학회 2004 Journal of Periodontal & Implant Science Vol.34 No.2

As the periodontal ligament cells show similar phenotype with osteoblasts, periodontal ligament cells are thought to play an important role in alveolar bone remodeling. According to recent studies, receptor activation of nuclear factor $^{\kappa}B$ ligand (RANKL) and osteoprotegerin (OPG) are expressed in periodontal ligament cells during tooth movement. Also periodontal ligament cells is known to play an important role in the progression of periodontal disease. This study was designed how the expression of RANKL and OPG in periodontal ligament cells was regulated by IL-1 ${\beta}in$ the concentration of $0.01{\sim}10$ ng/ml. The results are as follows; 1. Periodontal ligament cells which stimulated by 1L-1 ${\beta}$ increased soluble RANKL synthesis by dose-dependent pattern in the concentration of $0.01{\sim}10$ ng/ml. 2. 1L-1 ${\beta}$ induced mRANKL expression in dose-dependent manner in the concentration of $0.01{\sim}5$ ng/ml. 3. mOPG expression was not to be influenced by 1L-1 ${\beta}$. These results suggested that rat periodontal ligament cells could regulate osteoclastogenesis by stimulation of production of RANKL.

경년열화를 고려한 전단벽 구조물의 기계학습 기반 지진응답 예측모델 개발

김현수,김유경,이소연,장준수,Kim, Hyun-Su,Kim, Yukyung,Lee, So Yeon,Jang, Jun Su 한국공간구조학회 2024 한국공간구조학회지 Vol.24 No.2

Machine learning is widely applied to various engineering fields. In structural engineering area, machine learning is generally used to predict structural responses of building structures. The aging deterioration of reinforced concrete structure affects its structural behavior. Therefore, the aging deterioration of R.C. structure should be consider to exactly predict seismic responses of the structure. In this study, the machine learning based seismic response prediction model was developed. To this end, four machine learning algorithms were employed and prediction performance of each algorithm was compared. A 3-story coupled shear wall structure was selected as an example structure for numerical simulation. Artificial ground motions were generated based on domestic site characteristics. Elastic modulus, damping ratio and density were changed to considering concrete degradation due to chloride penetration and carbonation, etc. Various intensity measures were used input parameters of the training database. Performance evaluation was performed using metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analysis results show that neural networks and extreme gradient boosting algorithms present good prediction performance.

임상간호사의 전문 간호업무 수행도와 필요도 분석 - 강원도 상급병원 신경외과 영역을 중심으로

김현수,황주희,이현정,Kim, Hyun Su,Hwang, Ju Hee,Lee, Hyun Jung 경희대학교 동서간호학연구소 2022 동서간호학연구지 Vol.28 No.2

Purpose: This study was conducted to identify the performance and need of professional nursing care among nurses in a neurosurgery department at a tertiary hospital. Methods: This study used a descriptive design using a questionnaire with 77-item. The participants were 58 nurses with more than 3 years of clinical experience in both the neurosurgery intensive care unit and ward at a tertiary hospital in Gangwon province. Data collection was conducted from January to February of 2021. The performance and need for each workforce were analyzed with the mean and standard deviation, and the effectiveness of the difference between the performance and the need were analyzed with a paired t-test using SAS 9.4. Results: The recognition for work performance level was in order of direct nursing activities (3.20±.54), consultation and coordination (3.18±1.15), education (2.55±.85), administration (1.92±.86), and research (1.57±.89). The recognition for need level was in order of consultation and coordination (3.95±.83), education (3.91±.87), direct nursing practice (3.83±.55), research (3.49±.87), and administration (3.45±.54). The results showed a statistically significant differences between work performance and need (p<.001). Conclusion: It is required to hire professional nursing personnel who can bridge the gap between the performance and need of professional nursing workforce in a neurosurgery department at a tertiary hospital. A professional nurse may be a good alternative.

다중 MR 감쇠기의 효과적인 동시제어를 위한 제어알고리즘 개발

김현수,강주원,Kim, Hyun-Su,Kang, Joo-Won 한국공간구조학회 2013 한국공간구조학회지 Vol.13 No.3

A multi-input single-output (MISO) semi-active control systems were studied by many researchers. For more improved vibration control performance, a structure requires more than one control device. In this paper, multi-input multi-output (MIMO) semi-active fuzzy controller has been proposed for vibration control of seismically excited small-scale buildings. The MIMO fuzzy controller was optimized by multi-objective genetic algorithm. For numerical simulation, five-story example building structure is used and two MR dampers are employed. For comparison purpose, a clipped-optimal control strategy based on acceleration feedback is employed for controlling MR dampers to reduce structural responses due to seismic loads. Numerical simulation results show that the MIMO fuzzy control algorithm can provide superior control performance to the clipped-optimal control algorithm.

경사진 다이어그리드 비정형 초고층 건물에 대한 스마트 TMD의 제진성능평가

김현수,강주원,Kim, Hyun-Su,Kang, Joo-Won 한국공간구조학회 2011 한국공간구조학회지 Vol.11 No.4

근래에 들어와서 3T (Twisted, Tapered, Tilted)로 대별되는 비정형 초고층 건축물이 다수 계획되고 있다. 이러한 비정형 초고층 건물을 위해서 구조적인 효율성 및 조형성 때문에 다이어그리드 구조시스템이 현재까지 가장 널리 사용되고 있는 구조시스템 중의 하나이다. 건축적인 조형미 등의 이유로 경사진 비정형 초고층 건물에 대한 계획안이 다수 발표되고 있으며 다수의 구조물들이 다이어그리드 구조시스템을 활용하고 있다. 경사진 비정형 초고층 건물은 횡하중뿐만 아니라 자중에 의해서도 횡방향 변위가 발생한다. 따라서 정형적인 초고층 건물보다 횡방향 응답을 저감시카는 젓이 더 중요한 문제로 대두된다. 본 연구에서는 경사진 다이어그리드 비정형 초고층 건물의 지진응답을 저감시키기 위하여 스마트 TMD를 적용하였고 그 제어성능을 평가하였다. 스마트 TMD를 구성하기 위하여 MR 감쇠기를 사용하였으며 스마트 TMD는 그라운드훅 제어알고리즘을 사용하여 제어하였다. 100 층의 예제구조물에 대하여 제어를 하지 않은 경우와, 일반적인 TMD를 사용한 경우, 그리고 스마트 TMD를 사용하여 제어한 경우를 비교 검토하였다. 수지해석결과 스마트 TMD가 변위 응답 제어에는 우수한 성능을 나타냈지만 가속도응답제어에는 효과적이지 못했다. Recently, complex-shaped tall buildings represented by 3T(Twisted, Tapered, Tilted) are planed largely. A diagrid structural system is one of the most widely used structural system for complex-shaped tall buildings because of its structural efficiency and formativeness. Plans for tilted tall buildings are largely presented because of beauty of a sculpture and many of buildings use diagrid structural systems. Lateral displacements of tilted tall buildings are induced by not only lateral loads but also self weight. Therefore, reduction of lateral responses of tilted tall buildings is as important as typical tall buildings. In this study, a smart TMD is introduced to reduce seismic responses of tilted diagrid tall buildings and its control performance is evaluated. MR damper is employed for the smart TMD and ground-hook controller is used as a control algorithm for the smart TMD. 100-story tall building is used as an example structure. Control performances of uncontrolled case, controlled case with TMD and controlled case with smart TMD are compared and investigated. Numerical simulation has shown that smart TMD presented good control performance for displacement response but acceleration response was not controlled well.

다이어그리드 구조물-스마트 제어장치의 다목적 통합 최적화

김현수,강주원,Kim, Hyun-Su,Kang, Joo-Won 한국전산구조공학회 2013 한국전산구조공학회논문집 Vol.26 No.1

When structural design of a tall building is conducted, reduction of wind-induced lateral displacement is one of the most important problem. For this purpose, additional dampers and vibration control devices are generally considered. In this process, control performance of additional devices are usually investigated for optimal design without variation of characteristics of a structure. In this study, multi-objective integrated optimization of structure-smart control device is conducted and possibility of reduction of structural resources of a tall building with additional smart damping device has been investigated. To this end, a 60-story diagrid building structure is used as an example structure and artificial wind loads are used for evaluation of wind-induced responses. An MR damper is added to the conventional TMD to develop a smart TMD. Because dynamic responses and the amount of structural material and additional smart damping devices are required to be reduced, a multi-objective genetic algorithm is employed in this study. After numerical simulation, various optimal designs that can satisfy control performance requirement can be obtained by appropriately reducing the amount of structural material and additional smart damping device. 초고층 건물의 구조설계시 풍하중에 의한 횡방향 변위를 적절한 값 이내로 줄이는 것이 가장 중요한 문제 중에 하나이다. 이를 위해서 추가적인 감쇠기 및 진동제어장치를 사용하는 방법이 일반적으로 고려되고 있다. 이 때 일반적으로 구조물의 특성은 변화없이 추가되는 제어장치에 대해서만 최적설계를 수행하게 된다. 본 연구에서는 구조물과 스마트 제어장치의 다목적 통합 최적화를 통하여 추가되는 스마트 제어장치로 인하여 구조물의 물량을 줄일 수 있는 가능성을 검토하였다. 이를 위하여 다이어그리드 구조시스템이 적용된 60층 초고층 건물을 예제 구조물로 선택하였고, 인공 풍하중에 대한 풍응답을 검토하였다. 스마트 제어장치로는 TMD에 MR 감쇠기를 설치한 스마트 TMD를 사용하였다. 구조물의 응답과 구조물량 및 제어장치의 용량을 동시에 줄이는 것이 필요하므로 본 연구에서는 다목적 유전자알고리즘을 적용하였다. 수치해석결과 제어성능목표를 만족시키면서 구조물의 물량과 제어장치의 용량을 적절하게 줄일 수 있는 다양한 설계 최적안을 얻을 수 있었다.

중약진지역에 대한 MR 감쇠기로 구성된 스마트 면진시스템의 특성연구

김현수,강주원,Kim, Hyun-Su,Kang, Joo-Won 한국강구조학회 2012 韓國鋼構造學會 論文集 Vol.24 No.3

Smart base isolation systems developed for structures in high seismic regions cannot be directly applied to structures in regions of low-to-moderate seismicity, such as Korea. Therefore, the problems that occur by applying the smart base isolation system for high seismic regions to the structures in regions of low-to-moderate seismicity have been investigated in this study. To this end, a five-story building is used as an example, and an MR damper and low damping elastomeric bearings were used to compose a smart base isolation system. Artificial earthquakes are simulated for ground motions in regions of high and low-to-moderate seismicity. Based on numerical simulation results, the MR damper capacity that can provide good control is quite different among regions of high and low-to-moderate seismicity. Moreover, it is noted that the properties of a smart base isolation system for the regions of low-to-moderate seismicity should be carefully designed because the base isolation effects of the smart base isolation system for high seismic regions deteriorate when it is applied to the structures in regions of low-to-moderate seismicity. 강진지역에 있는 건축물을 지진하중으로부터 보호하기 위하여 개발된 스마트 면진시스템은 우리나라와 같은 중약진지역에 있는 건축물에 그대로 적용되기에는 많은 한계점이 있다. 따라서 본 연구에서는 강진지역에 있는 건축물을 위한 스마트 면진시스템을 중약진지역에 건설되는 건축물에 적용하였을 때 발생하는 문제점을 검토해보았다. 또한 이를 토대로 중약진지역에 건설되는 건축물을 위한 스마트 면진시스템의 개발시 고려해야할 사항에 대해 알아보았다. 수치해석을 위한 예제구조물로 5층 건물을 선택하였고 스마트 면진시스템은 MR 감쇠기와 저감쇠 탄성베어링을 사용하여 구성하였다. 강진지역과 중약진지역에서 발생하는 지진하중으로는 기존에 발생한 역사지진을 바탕으로 인공지진을 생성하였다. 수치해석결과 스마트 면진시스템이 우수한 성능을 발휘하는 MR 감쇠기의 용량이 강진지역과 중약진지역에 대하여 크게 다른 것을 알 수 있었다. 또한, 강진지역에 건설되는 구조물을 위하여 개발된 스마트 면진시스템을 그대로 중약진지역에 적용하면 면진효과가 상당히 줄어들므로 스마트 제어장치의 특성을 중약진지역에 맞추어 주의 깊게 설계되어야 함을 알 수 있었다.

두개의 렌즈형 레이저 막대들로 구성된 대칭형 공진기의 안정도 및 빔질의 수치적 분석

김현수,Kim, Hyun-Su 한국광학회 2004 한국광학회지 Vol.15 No.6

두개의 렌즈형 레이저 막대들로 구성된 대칭형 레이저 공진기의 안정도와 빔질 특성을 분석하고 열 복굴절 보상 특성을 수치적으로 분석하였다. 공진기는 열 효과에 의한 이중초점을 제거하기 위한 90$^{\circ}$ 회전자가 두개의 렌즈형 레이저 막대 사이에 삽입된 구조로 되어있다. 수치 분석을 통해 레이저 막대를 오목렌즈로 만들 경우 고출력 영역에서 안정도가 증가하고 빔질이 향상됨을 보였다. 또한 두개의 레이저 막대를 서로 맞댄 공진기 구조에서 열 복굴절이 잘 보상될 수 있음을 보였다. We analyse the beam characteristics of the thermal-birefringence compensated symmetric resonator which consists of two laser rods with rod-end curvatures. The numerical results show that the stability and the beam quality can be improved in high power operation region when the rod-ends are made in the form of a negative lens. The thermal birefringence of the symmetric two-rods resonator is shown to be well compensated when the two rods closely contact each other.