환절기 피해, 원인을 알고 치료하자

백정식 대한양돈협회 2005 養豚 Vol.27 No.3

TAS공법의 특징과 지반환경

여유현,백정식,최춘식,윤계한,황송연 한국지반공학회 2002 지반 : 한국지반공학회지 Vol.18 No.3

영兒院과 그의 入養의 現況과 問題点

김순희,백정식,채선묵 숭전대학교 사회사업학과 1979 社會事業硏究 Vol.4 No.-

직무중심의 성과주의 인사제도

신건호,백정식 단국대학교 경영경제연구소 2000 經營, 經濟硏究 Vol.2 No.-

Corporate's mission is to creat values in market, to develop and to prolong. Management is to evaluate, to actualize values effectively in market. The thinking of outcomes in corporate has been changed from sales amount, profits to social contribution, environmental creation. The key of innovation is performance - The idea of intellectual performance. The management based performance focuses on the effective and high quality performance in individuals of organizations. The future role of H.R.M. is to develop High Performer at last, to raise the corporate's power of value creation. The realization of corporate's mission comes true through employee's job. Accountability is composed of performance and activity. the personnel management based job classification is quite different from person related. The most important definitions are Accountability and Competency. Job based compensation is different from Seniority based compensation. Job based compensation will actualize the corporate's needs for exemple reduction of persennel expenses and motivation of young employees. Performance Management System has an important role in Pay for Performance system. Competency is another important ability and characteristics to create performance. To recruit and to transfer someone who have motivation and characteristics, to teach them skills and knowledge will be realistic and effective.

Evaluation of the Structural Performance of Tetragonal Lattice Girders

김승준,한택희,백정식,강영종 한국강구조학회 2013 International Journal of Steel Structures Vol.13 No.1

This paper presents an evaluation of the structural performance of tetragonal lattice girders for NATM tunnel construction. H-shaped steel ribs and triangular lattice girders have been widely used as a temporary support for NATM tunneling. H steel ribs have high flexural stiffness and strength, but they may induce unexpected internal gaps after shotcreting, because of their geometric characteristics. To overcome the problem, triangular lattice girders were developed. However, the lattice girder revealed frequent local failure at the joints of each bar. Moreover, those two supports show the quite low connection strength of members. Recently, a new type support, the tetragonal lattice girder, was developed to overcome the weaknesses of former supports. In this study, the structural performance of the new type support was studied by analytical and experimental methods. For the evaluation, 4-point flexural analysis, the conventional evaluation method, and arch analysis including stability analysis were performed. In addition, a 4-point flexural experiment was performed to evaluate the ultimate load carrying capacity, and observe whether local failure occurs or not. In the experimental study, a connected model was also considered as well as a unit model, in order to check the rationality of the connection method of the girder. All analytical and experimental results were compared with the structural performance of former supports.

TAS공법의 적용성과 지반환경 영향

천병식,여유현,백정식,최춘식 한국지반환경공학회 2002 한국지반환경공학회논문집 Vol.3 No.3

Generally, it is known that urethane injection is excellent in long-term durability and environment friendly for ground improvement. However, urethane grouting has short rise time thus the penetration distance from the injection point is so short. Therefore, urethane injection cannot be used for the site where requires ground improvement in deep location from the injection point. Other injection materials such as cement cannot be alternatives when rapid hardening is required. From this study, we improve disadvantage urethane injection by developing TAS method. From the field tests, it is ascertained that TAS increases injection distance over 10m, which is further than that of original urethane grouting. In addition, TAS has relatively short Rise-time compared to cement grouting thus instantaneous improvement can be mobilized right after the injection. Short Rise-time and long penetration distance provide excellent applicability for tunnel construction. 일반적으로 우레탄 주입은 장기 강도와 환경친화적인 측면에서 우수성을 보이고 있다. 하지만 우레탄 공법은 짧은 Rise- time을 가지고 있으므로 주입구에서부터 아주 짧은 침투 반경을 보인다. 그러므로 깊은 지점의 지반개량을 위해서는 우레탄 공법이 사용 될 수 없다. 시멘트와 같은 다른 주입재는 급속한 경화가 필요한 현장에서는 그 대안이 되지 못하였다. 따라서 본 연구를 통해서 우레탄 공법의 단점을 TAS 공법을 통하여 보강하고자 한다. 현장실험을 실시한 결과 TAS 공법은 기존의 우레탄공법을 통하여 침투 주입 할 수 있는 거리보다 훨씬 더 먼 거리의, 10m 주입이 확인되었다. 또한 TAS 공법은 시멘트 그라우팅에 비해 상대적으로 짧은 Rise-time을 보이므로 주입 후 즉각적인 지반보강효과를 확인 할 수 있다. 짧은 Rise-time과 긴 침투주입구간 등의 장점으로 TAS 공법은 터널등에서 그 적용성이 기대된다.

침습성 진균 감염증의 새로운 진단법인 석탄산 산화효소 전구체 시스템을 이용한 (1→3)-β-D-glucan 농도 측정법의 유용성 평가 연구

이기덕,윤종원,백정식,어중혁,이복률,김의석,박완범,김홍빈,김남중,오명돈,최강원 대한감염학회 2006 Infection and Chemotherapy Vol.38 No.3

Background : Prognosis of invasive fungal infection is supposed to be better when diagnosed earlier. (1→3)-β-D-glucan (BDG) test is considered useful in early diagnosis of invasive fungal infections among high-risk patients. A new diagnostic test using prophenoloxydase system to measure BDG level is developed. A study was performed to evaluate clinical usefulness of this new diagnostic test. Materials and Methods : 15 patients of confirmed invasive fungal infections and 38 healthy normal volunteers were enrolled. Plasma or serum BDG concentrations were measured using prophenoloxydase system. Assays for intra-run variability and inter-run variability were performed. A cut-off value was determined and sensitivity and specificity of the test were evaluated. Results : A cut-off value of 94.90 pg/mL was determined. Sensitivity and specificity of the test were 86.7% and 52.6%, respectively. Statistical analyses of inter-run variability and intra-run variability revealed the test is reliable (P≤0.001). Conclusion : BDG test using prophenoloxydase system is a sensitive and reliable test in non- invasive detection of invasive fungal infection.

사각 격자지보의 구조 성능 평가

김승준,한금호,원덕희,백정식,강영종,Kim, Seung-Jun,Han, Keum-Ho,Won, Deok-Hee,Baek, Jung-Sik,Kang, Young-Jong 한국강구조학회 2012 韓國鋼構造學會 論文集 Vol.24 No.3

본 논문은 신형식 사각 격지지보의 구조 성능 평가를 다룬다. 지금까지 NATM 공법을 이용한 터널 시공 시 콘크리트 라이닝 시공 전까지 터널 배면을 지지하는 구조체로서 H형 단면 강지보 및 삼각 격자지보가 주로 사용되었다. H형 단면 강지보는 동일 단면 높이를 갖을 때 삼각 격자지보보다 우수한 휨 성능을 보이지만, 단면이 복부판 및 플랜지로 구성되어 있어서 숏크리트 타설 후 콘크리트 라이닝 내부에 배면 공동이 많이 발생한다. 이를 해소하기 위해 개발된 삼각 격자지보는 숏크리트와 우수한 부착성을 보이나 부재와 부재 간 용접부에서의 파손이 빈번하게 발생한다. 이러한 문제점을 개선하기 위해 사각 격자지보가 개발되었고, 본 논문에서는 유한요소해석 및 하중재하실험을 통해 사각 격자지보의 구조 성능을 객관적으로 분석하였다. 해석연구에서는 강지보의 일반적인 성능평가방법인 4점 재하 휨 하중 해석을 수행하였고, 여기에 더하여 아치 해석을 통해 아치의 항복 하중 및 좌굴 하중 역시 검토하였다. 4점 재하 휨 하중 실험을 통해 사각 격자지보의 극한 상태 하중을 분석하였고, 기존의 격자지보에서 문제되었던 부재 간 접합부의 파손 여부를 검토하였다. 이렇게 해석 및 실험을 통해 신형식 사각 격자지보의 주요한 구조 성능을 평가하였고 이를 기존 격자지보와 비교하였다. In general, the H-shaped steel ribs or triangular lattice girders have been mostly used in constructing tunnels through the NATM construction method. The H-shaped steel rib has higher flexural and axial strength than the triangular lattice girder, but many unexpected gaps can occur in the concrete lining system after shotcreting if the H-shaped steel rib is used as the support system. To achieve better shotcreting quality, the triangular lattice girder was developed. However, in general, the triangle lattice girder has low flexural and axial strength. Likewise, the triangular lattice girder, which has circular sectional members, has so many fractures from welded points at the joints between the members. Finally, the new type of tetragonal lattice girder was developed to overcome those problems. In this study, the structural performance of the tetragonal lattice girders was evaluated through analytical and experimental studies. In the analytical studies, the four-point bending analysis, the traditional evaluation method to determine the flexural strength of the lattice girder, was performed. Moreover, the linear-elastic analysis and stability analysis of the arch structure made by the lattice girders were performed to measure structural performance. Experiments were likewise performed to compare the structural performances of the tetragonal girder with traditional triangular lattice girders.

MBP의 접촉저항 개선 방법

나태경(Na, Tae-Gyeong),김홍석(Kim, Hong-Seok),백정식(Baek, Jeong-Sik),성동묵(Seong, Dong-Muk),김태민(Kim, Tae-Min) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.06

직렬로 연결 된 다층의 단위전지 집합으로 구성되는 고체 고분자 연료전지의 적층전지는 에서 발생 할 수 있는 단위전지 간 전압손실과 압력구배를 최소화하기 위해 적층전지 내의 단위전지 외에 부품 및 재료를 추가하여 전압손실과 압력구배를 줄이는 방법에 대한 연구를 진행하였다. 체결압 구배를 최소화하기 위해 부드러운 층으로 이루어진 외곽부분과 딱딱한 층으로 이루어진 중심부를 가지는 필름을 전류집합체 뒤쪽에 첨가하였고, 분리판과 전류집합체 사이에서 발생 할 수 있는 전압손실을 방지하기 위해 높은 전기 전도성을 가지며, 평활도를 유지 할 수 있는 재료로 구성 된 복합층을 전류집합체와 분리판 사이에 첨가하였다. 압력구배 측정 및 다층전지 성능테스트 중 단전지간 전압손실을 측정하여 기 제작 된 첨가층들에 대한 영향의 정도를 파악하였다.

고분자 전해질 연료전지를 위한 연료주입구 설계 및 수치해석

엄승배(Uhm, Seung-Bae),나태경(Na, Tae-Kyung),김홍석(Kim, Hong-Suk),백정식(Baek, Jung-Sik),성동묵(Sung, Dong-Mug),김태민(Kim, Tae-Min) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.06

The Performance of a PEMFC stack is strongly dependent on the uniform reactants distribution on MEA. The uniform distribution can be achieved by flow-field pattern and manifold design optimized to satisfy operating conditions. This paper investigates uniform reactants distribution in channels by changing manifold shape and inlet mass flow rate. Typical U and Z shape and modified U and Z shape manifolds with buffer zone were designed. To check the uniform reactants distribution, standard deviation of mass flow rate was compared. The numerical results show that the inlet mass flow rate, inlet shape, and manifolds shape are critical factor for uniform distribution.