사회적 네트워크 유형 별 내향 중심성이 직무 스트레스에 미치는 차별적 영향

신인용(In Yoing Shin),이기현(Ki Hyun Lee),오홍석(Hong Seok Oh) 한국경영학회 2013 經營學硏究 Vol.42 No.4

As interdependent tasks have been increasing and the necessity of smooth communication among employees has been emphasized in organizations, scholars and practitioners are interested in the effects of social support from social relationships on job stress. Drawing on a social network perspective, we examined that social ties among organizational members influenced the level of job stress which they experience. We especially expected that the types of social networks in which employees were embedded (task-advice networks, friendship networks, and negative affect networks) were respectively linked to the provision, reception, and absence of social support, which in turn led to differently affecting individual job stress. According to the results of this study based on the survey data from employees in two organizations, the persons who occupied in-degree centrality in friendship networks were more likely to receive social support from the other employees and then their levels of job stress reduced, whereas the employees who were located in in-degree centrality in negative affect networks were less likely to receive social support from the other members, resulting in increasing the level of job stress they experienced. In addition, we hypothesized the U-shaped relationship between in-degree centrality in task-advice networks and individual job stress. In other words, we anticipated that the central persons in task-advice networks to the certain level tended to experience lower levels of job stress by the increased sense of control and self-esteem about themselves, and beyond the optimum level they were likely to experience higher levels of job stress because they were excessively granted the role of providing social support to the others. However, this hypothesis was not supported. This study suggests that the extent of centrality by the types of social networks differently influences the levels of job stress which organizational membersexperience.

물리시험 답안분석을 통한 교육대학생들의 전기에 관한 논리전개유형 및 오개념 분석

홍석인 인천교육대학교 과학교육연구소 2003 과학교육논총 Vol.15 No.-

건전지에 연결된 꼬마전구의 밝기를 전력의 관점에서 비교하는 물리 시험문제의 답안분석을 통하여 학생들의 논리전개 유형과 오개념을 분석하였다. 논리전개 유형은 문제풀이 과정에서 전기에 관한 지식들이 어떤 순서로 사용되는지 흐름도의 형태로 파악하였다. 학생들은 3가지 전력계산식 중에서 가장 비효율적인 식을 가장 선호(50%)하였다. 특이한 점은 문제풀이 과정에서 전혀 오류를 범하지 않은 학생들이 가장 비효율적인 식을 사용하였다는 것이다. 가장 효율적인 전력계산식을 사용하기 위하여 직렬회로에서의 전압분배에 대한 지식이 요구되므로 이와 같이 계층수준이 높은 개념에 대한 철저한 지도가 필요함을 알 수 있다. 또한 이 지식의 잘못된 이해가 학생들이 가지고 있는 오개념 중 가장 높은 비중(39%)을 차지하였다. 가장 중요한 3가지 오개념들은 전구 한 개가 소모하는 전력을 계산할 때 그 전구에 관한 전압, 전류, 저항 대신에 전체저항에 걸리는 전압(즉, 건전지의 기전력), 전체전류, 전체저항을 사용해야 하는 것으로 잘못 이해함으로써 발생되었다. 이에 대한 원인은 학생들이 물리공식에 나타나는 물리량들의 의미를 정확히 파악하지 않고 공식만을 피상적으로 암기하였기 때문으로 추정된다. 이를 치유하기 위하여 물리공식에 나타나는 물리량들을 문장의 형태로 정확히 표현하는 방법이 제안된다. We analysed teacher's university students' reasoning types and misconceptions through assessing their paper for a problem in physics examination which is to compare the brightness of the miniature light bulbs in terms of electric power dissipated in them. Reasoning types are represented as a sequence of the mental sets on electricity which are used in solving the problem. Among three kinds of formula about electric power, students preferred the most inefficient one(50%). In particular, the best students who did not make any logical error in solving the problem adopted the most inefficient formula. The most efficient formula of electric power requires the knowledge of voltage division in series circuit that is the concept of the higher hierarchical level. Moreover a misconception that results from the lack of this mental set takes the largest part(39%) among students' misconceptions. This leads us to put great emphasis on teaching the concepts of the higher hierarchical level. The most important three misconceptions come from the misunderstanding that in calculating the electric power dissipated in α light bulb the total voltage across the total resistance(the EMF of the battery), the total current, and the total resistance of the circuit are needed instead of the voltage, the current, and the resistance associated with that bulb. The origin of such a misunderstanding might be superficial learning of physics formula by heart without correct understanding of the physical quantities contained in it. To cure this it is suggested that they should be expressed in form of sentences that reveal their accurate meanings.

사람 위선암에서 cathepsin L의 발현증가

홍원선,홍석일,박인철,손영숙,정훈용,양석균,김해련,민영일 울산대학교 의과대학 1996 울산의대학술지 Vol.5 No.1

cathepsin L은 lysosomal cysteine 단백분해효소로서 기저막(basement membrane)과 세포외기질(extracellular matrix)을 파괴하여 암세포의 침윤과 전이에 중요한 역할을 하는 물질로 알려져 있다. 이러한 cathepsin L에 대한 mRNA 발현도를 5개의 사람 위선암(gastric adenocarcinoma) 세포주와 5명의 위선암 환자에서 채취한 조직에서 방사능으로 표지된 cathepsin L특이 cDNA를 사용한 Northern blot법으로 측정하였다. 위암의 전이병소에서 수립한 세포주인 SNU-5, SNU-16, MKN-45와 Kato Ⅲ에서는 cathepsin L mRNA가 발현되었으나 원발병소에서 수립한 AGS 세포주에서는 mRNA의 발현이 관찰되지 않았다. 5명의 위암 환자에서는 원발병소, 전이가 확인된 임파절 및 암 근처 정상 위점막에서 각각 조직을 채취하여 cathepsin L mRNA의 발현을 측정하였다. 원발병소와 전이병소에서는 모두 cathepsin L mRNA가 발현되었으나 정상 위점막조직에서는 전예에서 mRNA 발현이 관찰되지 않았다. 한편 mRNA의 발현도는 1예에서는 전이병소가 원발병소에 비해 높았으나, 2예에서는 전이병소에서 발현도가 낮았으며, 나머지 2예에서는 원발병소와 전이병소 사이에 차이가 없어, 원발병소와 전이병소 사이에 mRNA의 발현도의 일관성 있는 경향은 관찰되지 않았다. 이상의 결과는 cathepsin L은 위암의 발생과 진행에 있어 암세포의 침윤과 전이를 촉진하는 것 이외에 또 다른 역할을 할 가능성을 시사하고 있다고 사료된다. Cathepsin L, a lysosomal cysteine protease, is known to play an important role in cancer invasion and metastasis by degrading the components of basement membrane and extracellular matrix. The mRNA expression of cathepsin L was determined by Northern blot analysis using a radiolabeled cDNA specific for cathepsin L in five human gastric adenocarcinoma cell lines and five surgical specimens of primary gastric adenocarcinomas, their metastatic lymph nodes and matched adjacent normal mucosae. The mRNA of cathepsin L was expressed in all of the four cell lines established from the metastatic sites, SNU-5, SNU-16, MKN-45 and Kato Ⅲ, while not detected in one cell line established from the primary site, AGS. The mRNA was expressed in all of the five primary and five metastatic cancer specimens tested, while it was not detected in all matched normal mucosae. The intensities of the mRNA expressions, however, did not show the consistent pattern between primary sites and metastatic lymph nodes. These results suggest that cathepsin L may have the other function in addition to facilitation of the invasion and metastasis during the development and progression of stomach cancer.

최근 6년간 시행한 매독혈청검사 성적

임이석,김명남,홍창권,노병인,장진요,박애자 중앙대부설한국의과학연구소 1988 한국의과학 Vol.20 No.1

소아에서 발생한 골수이형성 증후군 2례

홍성진,윤석중,김성우,조형구,오명호,김기혁,이인성 건국대학교 의과학연구소 1996 건국의과학학술지 Vol.5 No.-

Myelodysplastic syndrome(MDS) is a group of acquired conditions characterized by progressive bone marrow failure associated with normocellular or hypercellular bone marrow that cannot be attributed to nutritional deficiency, chronic infection, or other chronic systemic illness, and cannot be reversed by the successful treatment of those conditions. Whereas the cases of secondary MDS occur at all ages, primary MDS is essentially a disease of elderly, though no age group is exempt and predomonant in men. The MDS is fundamentally clonal disorders at the level of the haemopoietic totipotent stem cell. Clinically, they are characterized by varing degrees of peripheral cytopenia(s) with morphological and functional abnormalities of blood elements. We have experienced two unrelated pediatric cases, who showed pancytopenia on admission and the characteristic marrow findings of MDS. The first case, a 12 months-old girl, showed increased reticulin with abnormal localization of immature precursor cells(ALIP) in her bone marrow, in addition to dysplastic features such as bi-and multi-nucleation of late normoblasts and internuclear bridging. She also showed 22% of blasts in her bone marrow cells thus classified in the category of RAEB-t after FAB classification. Also found were a chromosomal abnormality namely 46 XX t(14q21q), which was an unusual one. Her family brought her home and, 4 month later, she deceased. The second case, a 12 year-old boy, showed pancytopenia with Pseudo-Pelger-Huet anomaly in neutrophils but no blasts in the peripheral blood. Bone marrow of this case also showed the picture of dyserythropoiesis with binuclearity, internuclear bridging, nuclear fragments, multinuclearity of late normoblasts, in addition to megaloblastoid change in the normoblasts and increased mitosis in granulocytic series. No chromosomal abnormality was found. Classified as RA after FAB classification of MDS. Showed good response to conservative management for anemia for more than one year.

내부저항의 효과를 고려한 병렬연결된 건전지의 단자전압

홍석인,김현수 仁川敎育大學校 科學敎育硏究所 2002 과학교육논총 Vol.14 No.-

본 연구의 목적은 내부저항의 효과를 고려하여 병렬연결된 건전지의 단자전압 산출식을 유도하고 실험적으로 확인하며, 교육과정과의 연계성을 탐색하는데 있다. 초등학교 과학과 교육과정에서 다양한 전지의 연결에 대한 전구의 밝기를 이해하고자 아동들이 두 전지로 구성할 수 있는 모든 가능한 전지의 연결방식을 고려하였다. 전구의 밝기를 결정하는 것은 단자전압이며 전지의 내부저항에 의해 크게 영향을 받는다. 직렬연결의 경우는 비교적 간단하므로 병렬연결의 경우에 중점을 두어 연구하였고 연구결과를 정리하면 다음과 같다. 첫째, 두 개의 전지 A, B를 정방향(두 전지의 양극이 같은 방향)으로 병렬연결 하였을 때 단자전압 공식을 유도하였다. 단자전압은 내부저항이 작은 전지의 기전력이 더 큰 가중치를 갖는다. 그리고 전지를 역방향(두 전지의 양극이 반대 방향)으로 병렬연결 하였을 경우, 단자전압은 한 쪽 편 전지의 기전력의 부호를 바꾸어 줌으로써 간단히 유도할 수 있다. 만약 회로를 구성하는 전지들의 기전력과 내부저항이 비슷하다면 양쪽 전지들의 총 기전력이 크게 차이나는 경우에도 단자전압이 기전력에 비하여 매우 작은 결과가 얻어진다. 둘째, 전지의 정방향 병렬연결에 대하여 단자전압을 측정한 결과 이론값과 측정값이 잘 일치하였다. 그러나 전지의 역방향 병렬연결 실험에서는 건전지의 내부저항에서 일어나는 큰 전압 강하에 의한 전지의 발열로 내부저항값이 변화되어 약간의 오차가 발생하였다. 셋째, 본 연구와 초등학교 과학과 교과내용과의 연계성을 구체적인 예를 통하여 검토하였다. 그리고 초등학교 과학 교과서와 초등과학교육 논문에 나타난 역방향 직렬연결과 역방향 병렬연결의 경우 본 연구의 결과를 적용하면 전구의 불켜기 결과를 쉽게 예측할 수 있음을 살펴보았다. The present research was motivated by the desire for understanding the brightness of a miniature electric bulb connected to various combinations of batteries in elementary science curriculum. We consider all the kinds of battery combinations consisting of two batteries. It is the terminal voltage that determines the brightness of the bulb and is much affected by the internal resistances of batteries. Because the results of series combinations of two batteries are relatively simple, our study is focused on their parallel combinations. The results of the present research are summarized in the following: First, the formula for the terminal voltage is derived in the case that two batteries are connected in parallel in a usual way (in this case positive poles of two batteries point to the same direction). The electromotive force(emf) of the battery with a smaller internal resistance has a higher weighting factor in terminal voltage. For the case that two batteries are connected in parallel in a reverse way(in this case positive poles of two batteries point to the opposite directions), the formula for the terminal voltage can be easily derived by simply changing the sign of the emf of the battery in one side. If the emfs and the internal resistances of the batteries in the circuit take similar values, though the total emfs of the batteries in both sides show great difference, the terminal voltage is much less than the emfs. Second, for the usual parallel combination of the batteries the experimental values of the terminal voltage are in good agreement with the theoretical prediction. In the case of the reverse parallel combination they exhibits some differences. Much heat generated in batteries in this case results from the power loss due to the big voltage drop that occurs in the internal resistances of the batteries because the terminal voltage is very small. The error between experimental data and theoretical prediction might be originated from the change of internal resistance due to the heat. Third, we examined the relationship between our research and the elementary science curriculum through specific examples. In addition, for the reverse series combination and the reverse parallel combination which are considered in an elementary science textbook and a research paper on elementary science education, respectively, the result of lighting the bulb can be easily predicted by applying the result of our research.

Comparison of clinical characteristics and prognosis of pneumocystis jirovecii pneumonia in patients with immunocompromised and non-immunocompromised conditions

( Hong-joon Shin ),( Min-seok Kim ),( Bo Gun Kho ),( Ha Young Park ),( Tae-ok Kim ),( Cheol-kyu Park ),( Yong-soo Kwon ),( In-jae Oh ),( Yu-il Kim ),( Sung-chul Lim ),( Young- Chul Kim ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Background: Pneumocystis jirovecii pneumonia (PCP) is a fatal respiratory infection frequently associated with immunocompromised (IC) conditions. Although PCP has been reported in non-immunocompromised (non-IC) patients, however, few studies have been conducted. This study was aimed to compare the clinical characteristics and prognosis of PCP in IC and non-IC patients. Methods: We retrospectively analyzed patients who were suspected of having PCP with polymerase chain reaction (PCR) test positive for Pneumocystis jirovecii from January 2013 to May 2019. IC group was classified into human immunodeficiency virus (HIV), hematologic, solid organ tumor, rheumatologic and immunosuppressive agent group. Results: A total 192 PCP cases including 176 IC cases and 16 non-IC cases were analyzed. Patients were older in the non-IC group compared with the IC group (72.5 vs. 62.0, P=0.002). Hematologic malignancy was the most common (47.2%), followed by HIV (14.8%) in the IC group. The interval between test for PCP-PCR and PCP treatment was shorter in the IC group compared with non-IC group (0 [0-3] vs. 4.0 [2.2-7.7] days, P=0.001). In-hospital mortality was not significantly different between IC and non-IC groups (43.2% vs. 62.5%, P=0.189). Age (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.02-1.09; P=0.002) and PaO₂/FiO₂ (OR 0.99; 95% CI 0.98-1.00; P=0.039) were the prognostic factors for in-hospital mortality in the multivariate logistic regression analysis. There was no significant difference between IC and non-IC group in 6-month survival. However, HIV group had better 6-month survival compared with non- IC group in the subgroup analysis (Hazard ratio 0.16; 95% CI 0.05-0.53; P=0.003]. Conclusion: Patients with PCP in non-IC group were older than IC group, and had similar prognosis as other IC group except HIV group.

In_xGa_1-xN/GaN 다중양자우물 구조의 광학적 성질 연구

김기홍,김인수,박헌보,배인호,유재인,장윤석,Kim, Ki-Hong,Kim, In-Su,Park, Hun-Bo,Bae, In-Ho,Yu, jae-In,Jang, Yoon-Seok 한국진공학회 2009 Applied Science and Convergence Technology Vol.18 No.1

$In_xGa_{1-x}N$/GaN 다중양자우물 구조의 EL 특성을 온도와 주입전류 변화에 따른 특성을 조사하였다 저전류와 고전류 주입시 EL 효율의 온도 의존 변화는 매우 다르게 나타나는데, 이러한 온도와 전류의 변화에 의한 독특한 EL 효율의 변화는 내부전기장의 존재 하에 순방향 바이어스에 기인한 외부전기장의 영향인 것으로 볼 수 있다. 그리고 $In_xGa_{1-x}N$/GaN 다중양자우물 구조에서 In 성비의 증가는 발광파장위치의 적색이동을 보였다. 15K에서 주입 전류의 증가에 따라 녹색 양자우물 구조는 80 meV와 청색 양자우물 구조는 22 meV의 청색 편이를 하였다. 이는 전류의 증가에 의해 단위 시간당 생성되는 캐리어 수가증가하게 되고 그에 따라 subband가 급격히 채워지는 band filling 현상이 일어나게 되어 짧은 파장에서 재결합이 증가하기 때문이다. 그리고 청색과 녹색 다중 양자우물구조의 짧은 파장 쪽으로의 편이 차이는 In 농도에 기인한 것으로 In 농도가 높으면 양자우물 깊이가 증가되어 더 강한 양자속박효과가 작용하여 캐리어 구속력이 증가하기 때문 것으로 볼 수 있다. Temperature and injection current dependence of electroluminescence(EL) spectral intensity of the $In_xGa_{1-x}N$/GaN multi-quantum wells(MQW) have been studied over a wide temperature range and as a function of injection current level. It is found that a temperature-dependent variation pattern of the EL efficiency under very low and high injection currents shows a drastic difference. This unique EL efficiency variation pattern with temperature and current can be explained field effects due to the driving forward bias in presence of internal(piezo and spontaneous polarization) fields. Increase of the indium content in $In_xGa_{1-x}N$/GaN multiple quantum wells gives rise to a redshift of 80 meV and 22 meV for green and blue MQW, respectively. It can be explained by carrier localization by potential fluctuation of multiple quantum well and MQW structures also shows a keen difference owing to the different indium content in InGaN/GaN MQW.

미세침 흡인 세포진단 검사상 불명확한 소견을 보이는 갑상선 결절의 병리학적 진단

이석인(Seok In Lee),김민선(Min Seon Kim),김현규(Hyun Kyu Kim),김원배(Won Bae Kim),박경수(Kyong Soo Park),김성연(Seong Yeon Kim),조보연(Bo Youn Cho),이홍규(Hong Kyu Lee),고창순(Chang Soon Koh),고경수(Kyung Soo Ko) 대한내과학회 1995 대한내과학회지 Vol.48 No.4

N/A Objectives: Thyroid nodule is a common clinical problem but there is a few cases of malignant lesions requiring surgery. So it is a critical issue to distinguish benign from malignant nodules and to select a patient for surgery. Although there are some variations in the accuracy of the diagnosis, fine needle aspiration biopsy of thyroid nodule has been accepted as a accurate diagnostic procedure in the management of nodular thyroid disease. So it was desirable to verify the usefulness of the fine needle aspiration (FNA) cytology in differentiating from malignant lesions and to clarify the problematic issues concerning the cytopathologic features of indeterminate cytology, which is equivocal to describe benign or malignant lesion, Methods: We examined the medical records retrospectively of all patients who wore engaged in fine needle aspiration cytology or thyroidectomy due to thyroid nodules from 1988 to 1992. Results: 1) Eighty hundreds fifty nine cases of FNA cytology was done in 1992 and 659 cases(75.9%) were adequate for cytopathologic diagnosis. And the diagnoses showed 558 cases of benign, 37 cases of malignant and 57 cases of indeterminate features. 2) The sensitivity of benign nodules were 91.2% and that of malignant lesion were 85.7%, respectivety. The overall accuracy of fine needle aspiration cytology of the thyroid nodule was 88.4%. 3) From 1988 to 1992, the medical records of 140 patients showing indeterminate cytology of thyroid nodules by FNA were reviewed. Among them, 67 patients were operated for the thyroid nodule till June 1993 and pathologic diagnoses were confirmed, The pathologic diagnoses were consisted of 27 cases(40.3 %) of benign lesions and 40 cases(59.7%)of malignant lesions. Conclusion: FNA cytology of the thyroid nodule was useful in distinguishing benign from malignant nodules and surgical excision of the cases showing in- determinate cytopathologic features seems reasonable.

MgCl₂溶液內에서 STS 304 HP Stainless Steel 熔接部의 破壞擧動에 對한 硏究

金永奭,丁太權,朴昌彦,洪錫柱,梁仁榮,金基玉,朴煥奎,李茂錫,曺圭宰,鄭在康 조선대학교 생산기술연구소 1983 生産技術硏究 Vol.1983 No.-

This paper is based on an experiment analysing the stress corrosion cracking behaviour of welding specimens compared to that of non-welding specimens of STS 304 HP stainless steel in corrosion solution. As a corrosion condition, stainless steel has been known to be the most fragile in a solution of 42% MgCl₂heated to the boiling point, therefore the experiment was carried out in this condition. The experiment was carried out with argon gas TIG welding specimens and non-welding ones made of stainless steel plates, thickness 2mm, by tensile force. At this time, the tensile force was taken to be the value of the yield strength of the tensile test specimens divided by the safety factor of 3.0 to 3.5, 4.0, 4.5, and 5.0. In this paper, the relations between Time of Initial Crack, Time of Failure, Time of Final Fracture and Crack Propagation Length were investigated and then plotted. Furthermore, the relations between Stress Intensity Factor K proposed by Irwin and the Time of Initial Crack, the Time of Failure, the Time of Final Fracture were calculated and plotted. At the last, all the relations plotted were expressed to normal equations by computer, and the equations were used to analyse the data obtained in the experiment. The conclusions obtained in this study are as follows: 1. Welding materials, compared with non-welding ones, as the Time of Initial Crack, the Time of Failure, and the Time of Final Fracture were generally very fast, appeared to be a phenomenon of unstable brittleness fracture. 2. Non-welding materials, compared with welding ones, as the safety factor was larger or the working stress was smaller, appeared to be a phenomenon that the longer had had greater durability. Therefor, welding materials must be considered enough to be used in heate affected and stress corrosion atmosphere. 3. The normal equations of the Time of Initial Crack and the variation rate to the same Stress Intensity Factor K are as follows: (A) Non-welding T =259702.4-5451.2 K+28.386 K² T = -5451.2+28.386 K (B) Welding T= -332.693+28.043 K-0.211 K² T' =28.043-0.211 K here, T; Time of Initial Crack, T'; Variation Rate of Time of Initial Crack to Stress Intensity Factor K, K ; Stress Intensity Factor.