일-가정의 갈등과 지식공유: 고용 안정성의 매개 효과와 공감적 리더십의 조절 효과

이민,설현도 K기업경영연구원 2022 KBM Journal(K Business Management Journal) Vol.6 No.1

In recent socio-economic changes, the work-life balance is becoming a very important issue and a major task to be solved. In this situation, firms need to find effective knowledge sharing methods for continuous growth and development. The purpose of this study is to examine how work-family conflict affects knowledge sharing and what role job security and resonant leadership play in this process. For this purpose, this study examines the effects of work-family conflicts, job security perceptions and knowledge sharing behaviors on worker in the new generation workers (1980-2000) in China. Also, the mediating effect of job security and the moderating effect of resonant leadership in the relationship between work-family conflict and knowledge sharing behavior were examined. In order to test the hypothesis of this study, 215 questionnaires collected from workers of in Jiang su Province, China were used. The hypothesis test results are as follows. First, it was confirmed that work-family conflict had a negative effect on job stability and knowledge sharing. In other words, work-family conflicts caused by conflicts between the family and the workplace resulted in a decrease in their own resources, a threat to job security, and a decrease in knowledge sharing activities to protect their resources due to a sense of competition with colleagues. Second, it was confirmed that perception on job security had a positive effect on knowledge sharing. Recognition of high employement security of organizational members increases trust among colleagues during the work process, shares one's knowledge to solve work problems, reduces stress and improves psychological state by judging the perception of high level of job security. It was expected to increase the sense of belonging and identity of the organization. Third, it was shown that perception on job security plays a mediating role between work-family conflict and knowledge sharing. Fourth, it was confirmed that resonant leadership had a moderating role in the relationship between perceptions on work-family conflict and job security. Based on the above research results, theoretical and practical implications were presented, and the limitations of the study and future research directions were also presented.

Altered Regional Cerebral Blood Flow Associated with Mood and Sleep in Shif Workers: Cerebral Perfusion Magnetic Resonance Imaging Study

박윤경,김재훈,최수정,김성태,주은연 대한신경과학회 2019 Journal of Clinical Neurology Vol.15 No.4

Background and Purpose Shif work disrupts the body’s circadian rhythms and increases the risk of health problems. Despite evidence of neuropsychological disturbances in shif workers (SW), the brain functional status as measured by brain perfusion in chronic shif work has not been evaluated previously. We investigated the regional cerebral blood fow (rCBF) in SW using perfusion MRI (pMRI) and evaluated the relationships between altered rCBF and sleep, mood, psychometric measures, and quality of life. Methods Fifteen rotational SW and 15 day workers (DW) were enrolled. The participants were all female nurses working at a university-afliated hospital. During 2 weeks of actigraphy they underwent pMRI scanning and psychometric testing on the last day immediately after working. Demographic characteristics, insomnia, daytime sleepiness, and mood were compared between the groups. Results Te participants were aged 35.3±2.9 years (mean±SD) and had been performing their current work for more than 2 years. Te demographic characteristics did not difer between SW and DW, but the levels of insomnia, anxiety, depression, and hyperactivity-restlessness in psychometric measures were higher in SW than in DW. Cerebral perfusion in SW was signifcantly decreased in the cuneus, fusiform/parahippocampal gyri, and cerebellum of the right hemisphere, while it was increased in the inferior occipital gyrus of the lef hemisphere. Perfusion changes in SW were signifcantly correlated with depression and insomnia severity. Te onset and duration irregularity of sleep among SW were related to insomnia, mood, hyperactivity/restlessness, and quality of life. Conclusions SW experience considerably more insomnia and mood disturbances than do DW, and this is signifcantly related to perfusion changes in multiple brain areas.

A cause of the intermittent FEAD belt ticking noise due to the abnormal behavior of a hydraulic autotensioner

Keychun Park,Hyungshin Kim,Kootae Kang,Jongwon Lee 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

A cause of the intermittent belt noise is analyzed by rig tests for the damping scopes of the autotensioner and the theoretical consideration for its vibratory responses. Because this noise was not reported in the previous literature to the authors’ knowledge, it has been determined to be worthwhile to investigate the root cause of it. Through investigation in the problematic engine in vehicle, the abnormal strokes of the autotensioner were detected without any distinguishable engine firing order excitation. In the following rig test to disregard the engine effects, the current design of the autotensioner is shown to have relatively long idle strokes, being vulnerable to the small amount of higher order engine excitations which have been nearly ignored in the autotensioner design. The idle stroke is judged to be closely related to the intermittent ticking noise from the coincident occurrence. Moreover, it is believed to be the aftermath of the check valve resonance. On these findings, the new design is proposed to reduce the idle strokes and it is reported that the modified tensioner satisfies all the design requirements without any intermittent abnormal behaviors.

대학생의 학업성취도에 따른 시각적 작동 기억 차이

홍재란(Jaeran Hong),황정하(Jungha Hwang),김은정(Eunjung Kim) 한국방사선학회 2012 한국방사선학회 논문지 Vol.6 No.3

작동 기억력은 학업성취도와 높은 상관을 보이는 요인으로 알려져 있다. 본 연구에서는 정상 대학생중 학업성취도 상위군과 하위군 학생들이 시각적 작동 기억의 부호화와 인출과제를 수행함에 있어 대뇌 활성화에 어떠한 차이가 있는 지를 기능적 자기공명영상법을 이용하여 알아보고자 하였다. 실험에 동의한 20명의 대학생들을 학업성취도 상위군 10명과 하위군 10명으로 나눴다. 십자가를 응시하는 휴지기와 도형을 기억하고 인출하는 활성기가 2번 반복되는 210초 프로토콜을 적용하였고, 유의수준 95%에서 두 군의 대뇌 활성화 차이를 알아보았다. 부호화의 경우 작동 기억을 담당하는 양측 배측 전전두엽(BA 46)과 주의력과 관련 있는 하두정엽과 시각 연합영역에서 상위군이 하위군에 비해 높은 활성화를 보였고, 인출의 경우 우측 배측 전전두엽(BA 44)과 모양의 판단과 관련 있는 우측 방추 상회와 설상회 등에서 우세를 보였다. 반면 하위군은 부호화의 경우 대상회에서 인출의 경우 시상과 기저핵 그리고 소뇌 등에서 상위군에 비해 높은 활성화를 보였다. 결론적으로 학업성취도 상위군이 부호화의 경우 작동 기억과 주의력에 관여하는 영역에서 인출의 경우 판단에 관련된 영역에서의 활성화가 높아 하위군에 비해 효과적인 작동 기억이 이루어짐을 알 수 있었다. It was well known that working memory highly related with academic achievement. The aim of this study was to investigate the differences of brain activation which visually evoked working memory(encoding and retrieval) through functional Magnetic Resonance Imaging(fMRI) in Higher Academic Achievement Group(HAAG) and Lower Academic Achievement Group(LAAG) of college students. 20 assigned college students participated in fMRI studies. They underwent totally 210 seconds repeated paradigm. Stimulation paradigm composed with resting time and encoding and retrieval seeing the figures from the mirror with head coil. The brain activation maps and their quantification were analyzed by the statistical parametric mapping(SPM99) program from level of significance 95%. HAAG was more significantly higher than LAAG in bilateral prefrontal lobe(brodmann 46) associated with working memory, inferior parietal lobe associated with attention, and visual association area in encoding figures test. Right dosoprefrontal lobe(BA 44), right fusiform gyrus associated with decision of figure and, lingual gyrus were more activated in retrieval test with HAAG. On the other hand, LAAG was more significantly higher than HAAG in cingulate gyrus during encoding test. Thalamus, basal ganglia, cerebellum were more activated in retrieval test. Consequently, We could guess from these results HAAG more effectively executed than LAAG in visual working memory test.

소형산업용 인덕션 히터의 최대에너지 전달에 관한 연구

이정빈(Jeong-Bin Lee),김태명(Tae-Myoung Kim),김영완(Young-Wan Kim) 한국전기전자학회 2021 전기전자학회논문지 Vol.25 No.3

본 논문에서는 유도 가열코일의 인덕턴스 변화 환경에서 스위칭주파수를 가변하여 최대 가열 전력이 전달될 수 있는 유도 가열 방식을 제안하였다. 가열코일내 피 가열체 종류 및 가열코일과의 근접도에 따라 공진회로의 공진주파수가 변화하게 되며, 공진주파수와 스위칭주파수 관계에 따라 유도가열기 소자의 파손 또는 손실이 발생하여 최대 전력 전달이 어려울 수 있다. 공진주파수의 변화에 따른 가열 전력을 감지하여 최대 전력 전달이 유지되도록 스위칭주파수를 가변하도록 하였다. 공진주파수 변화에 대응하는 스위칭주파수 가변에 따라 요구하는 출력 변화 범위내로 제어될 수 있는 제안된 방식의 결과를 통하여 거의 일정한 출력전력(0.43 dB 이내) 전달이 가능한 스위칭주파수 가변특성을 갖는 유도가열기의 전력 효율성을 확보할 수 있었다. Induction heating method that allows the maximum heating power to be delivered by varying switching frequency in the inductance change of the work coil of induction heater was proposed in this paper. Depending on the type of work piece in the work coil and proximity to the work coil, the resonance frequency of the resonant circuit will be changed. It may be difficult to deliver the maximum power due to the damage of the induced heater element or switching loss depending on the resonance frequency and switching frequency operating relationship. The switching frequency was variable to maintain the maximum power transmission by sensing the heating power due to the change of the resonance frequency. Through the result of the proposed method that can be controlled within the required output change range according to the change of the switching frequency corresponding to the change of the resonance frequency, the induction heater having a variable switching frequency characteristic that can transmit almost constant output power (within 0.43 dB) power efficiency was achieved.

Changes in Effective Connectivity According to Working Memory Load: An fMRI Study of Face and Location Working Memory Tasks

JoonShik Kim,WiHoon Jung,DoHyung Kang,JiYoung Park,JoonHwan Jang,JungSeok Choi,ChiHoon Choi,Jejoong Kim,JunSoo Kwon 대한신경정신의학회 2012 PSYCHIATRY INVESTIGATION Vol.9 No.3

Objective-The functional strategic mechanisms in the brain during performing visuospatial working memory tasks, especially tasks with heavy load, are controversial. We conducted the functional magnetic resonance imaging (fMRI) while sixteen subjects were performing face- and location-matching n-back tasks to examine causal relations within the frontoparietal networks. Methods-We applied a sophisticated method, the structural equation modeling (SEM), to the fMRI data. The imaging data were analyzed by extracting the task-related eigenseries using the principal component analysis (PCA) and then by applying a form of data-driven model called the automated search method. Results-The SEM analyses revealed a functional shift of network connectivity from the right to the left hemisphere with increasing load in the face-matching n-back tasks while the location-matching tasks required bilateral activation. In the locating matching n-back tasks, a pattern of parallel processing was observed in the left phonological loop and the right inferior parietal regions. Furthermore, object working memory-related activities in the left hemisphere reliably contributed to performance of both the face- and location-matching 2-back tasks. Conclusion-Our results are consistent with previous reports in terms of demonstrating parallel and distributed information processing during performing working memory tasks with heavy loads. Our results additionally suggest a dynamic shift between the fast imagery circuit (right hemisphere) and the stable verbal circuit (left hemisphere), depending on task load.

International Myeloma Working Group의 최신 가이드 라인에 따른 다발성 골수종의 영상검사법 및 MY-RADS에 따른 전신 MRI에서의 영상 획득과 반응 평가 소개

A Yeon Son,Hye Won Chung 대한영상의학회 2023 대한영상의학회지 Vol.84 No.1

Multiple myeloma (MM) is a malignant hematologic disease caused by the proliferation of clonal plasma cells in the bone marrow, and its incidence is increasing in Korea. With the development of treatments for MM, the need for early diagnosis and treatment has emerged. In recent years, the International Myeloma Working Group (IMWG) has been constantly revising the laboratory and radiological diagnostic criteria for MM. In addition, as whole-body MRI (WBMR) has been increasing used in the diagnosis and treatment response evaluation of patients with MM, the Myeloma Response Assessment and Diagnosis System (MY-RADS) was created to standardize WBMR image acquisition techniques, image interpretation, and response evaluation methods. Radiologists need to have a detailed knowledge of the features of MM for accurate diagnosis. Thus, in this review article, we describe the imaging method for MM according to the latest IMWG guidelines as well as the image acquisition and response evaluation technique for WBMR according to MY-RADS.

Brain Activation Patterns Associated with the Effects of Emotional Distracters during Working Memory Maintenance in Patients with Generalized Anxiety Disorder

박종일,양종철,김광원,Gwang-Woo Jeong,Gyung-Ho Chung 대한신경정신의학회 2016 PSYCHIATRY INVESTIGATION Vol.13 No.1

Few studies have assessed the neural mechanisms of the effects of emotion on cognition in generalized anxiety disorder (GAD) patients. In this functional MRI (fMRI), we investigated the effects of emotional interference on working memory (WM) maintenance in GAD patients. Fifteen patients with GAD participated in this study. Event-related fMRI data were obtained while the participants performed a WM task (face recognition) with neutral and anxiety-provoking distracters. The GAD patients showed impaired performance in WM task during emotional distracters and showed greater activation on brain regions such as DLPFC, VLPFC, amygdala, hippocampus which are responsible for the active maintenance of goal relevant information in WM and emotional processing. Although our results are not conclusive, our finding cautiously suggests the cognitive-affective interaction in GAD patients which shown interfering effect of emotional distracters on WM maintenance.

Brain Activation Patterns Associated with the Effects of Fearful Distractors during Working Memory Maintenance in Patients with Schizophrenia

Jong-Il Park,김광원,Gwang-Woo Jeong,Jong-Chul Yang 대한정신약물학회 2019 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.17 No.1

Objective: The neural correlates underlying the effects of emotional distraction during working memory (WM) tasks in patients with schizophrenia have yet to be clearly identified. Thus, the present study employed functional magnetic resonance imaging (fMRI) to investigate the effects of emotional distraction involving fear during WM maintenance in patients with schizophrenia. Methods: This study included 17 patients with schizophrenia who were diagnosed based on Diagnostic and Statistical Manual of Mental Disorders fourth edition, text revision (DSM-IV-TR) criteria and 17 matched healthy controls. Event-related fMRI data were acquired while the participants performed a delayed-response WM task that included neutral and fearful distractors. Results: Patients with schizophrenia may have tried to maintain WM function during the presentation of task-irrelevant fearful distractors that induced interruption and required attention. Compared to healthy controls, the schizophrenia patients exhibited significantly increased activity in the dorsolateral prefrontal cortex, medial prefrontal cortex, superior temporal gyrus, middle temporal gyrus, insula, hippocampus, caudate nucleus, and postcentral gyrus in a delayed-response WM task when presented with fearful relative to neutral distractors. In addition to its series of increased brain activations, prefrontal areas exhibited interconnections with more caudal brain regions, including temporal areas and the hippocampus and insula. Conclusion: The present study identified specific brain areas associated with the interaction between emotional regulation and cognitive functioning during fearful distractors presented while patients with schizophrenia performed a WM maintenance task. These findings further the current understanding of the neural correlates underlying the effects of emotional distraction on cognitive functioning in patients with schizophrenia.

유년기 정신적 외상을 경험한 외상후 스트레스장애 환자에서 무의식적 감정 자극이 의식적 작업기억 수행에 미치는 영향에 관한 기능적 자기공명영상 연구

엄준선,양종철,박종일,김광원 한국정신분석학회 2019 精神分析 (Psychoanalysis) Vol.30 No.4

Objectives: Few studies have assessed the neural mechanisms of the effects of unconscious emotional distracter on cognition in posttraumatic stress disorder (PTSD) patients. Thus, this study used functional magnetic resonance imaging (fMRI) to investigate the effects of unconscious emotional distraction involving fear during conscious working memory (WM) maintenance in patients with PTSD. Methods: This study included 10 patients with PTSD and positive early trauma inventory diagnosed based on Diagnostic and Statistical Manual of Mental Disorders fourth edition-text revision criteria, and 10 matched healthy controls. Event-related fMRI data were obtained while the participants performed a WM task (face recognition) with neutral and unconscious emotional distracters. Results: Patients with PTSD may have sought to maintain WM function during the presentation of task-irrelevant emotional distractors that induced interruption and required attention. Compared to healthy controls, the PTSD patients exhibited significantly increased activity in the superior frontal gyrus, middle frontal gyrus, superior temporal gyrus, middle temporal gyrus, and lingual gyrus in a delayed-response WM task when presented with unconscious emotional and fearful stimuli relative to neutral distracters. Conclusion: This study identified specific brain areas associated with the interaction between emotional regulation and cognitive functioning during unconscious emotional distracters presented while patients with PTSD performed a WM maintenance task. There was no difference in brain activation between the two groups at the conscious level of neutral distractors, but under the unconscious emotional distracters, PTSD patients showed a specific activation of the brain.