• 지식경영연구
• /
• 제16권2호
• /
• pp.139-172
• /
• 2015

Employee's agility is becoming a primary factor of improving individual work performance. Employee's agility refers to responsiveness or behavior of employees in the context of work environment change. The purpose of this study is to examine the relationship between employee's agility and work performance in the perspective of agility's influence factors(absorptive capacity, IT resource use, readiness to change) and knowledge-oriented leadership, A survey was conducted for gathering data (a total of 262 employees from 35 industrial organizations) to test the relationships. The results of analysis show that employee's agility is a driving force leading to individual work performance, that employee's absorptive capacity, IT resource use, readiness to change, and knowledge-oriented leadership are the significant influential factors of employee's agility, and that knowledge-oriented leadership strengthens the link between employee's absorptive capacity and agility. For theoretical and practical contributions, the research presents the grounds for arguments that employee's agility is employee's dynamic capability for individual work performance under work environment change, and that organizations trying to improve employee's agility need to explore employee's behavioral attitudes under individual, leader, and organizational dimensions. Limitations arisen in the course of the research and suggestions for future research directions are also discussed.

• The Korean Journal of Physiology and Pharmacology
• /
• 제7권2호
• /
• pp.103-109
• /
• 2003

The cellular mechanisms that contribute to the acceleration of atherosclerosis in diabetes are poorly understood. Therefore, the potential mechanisms involved in the diabetes-dependent increase in vascular smooth muscle cell (VSMC) proliferation was investigated. Using primary culture of VSMC from streptozotocin-induced diabetic rat aorta, cell proliferation assay showed two-fold increase in cell number accompanied with enhanced superoxide generation compared to normal VSMC, 2 days after plating. Both the increased superoxide production and cell proliferation in diabetic VSMC were significantly attenuated by not only tiron (1 mM), a superoxide scavenger, but also by diphenyleneiodonium (DPI; $10{\mu}M$), an NAD(P)H oxidase inhibitor. NAD(P)H oxidase activity in diabetic VSMC was significantly higher than that in control cell, accompanied with increased mRNA expression of p22phox, a membrane subunit of oxidase. Furthermore, inhibition of p22phox expression by transfection of antisense p22phox oligonucleotides into diabetic VSMC resulted in a decrease in superoxide production, which was accompanied by a significant inhibition of cell proliferation. Based on these results, it is suggested that diabetes-associated increase in NAD(P)H oxidase activity via enhanced expression of p22phox contributes to augmented VSMC proliferation in diabetic rats.

• 전력전자학회논문지
• /
• 제25권4호
• /
• pp.279-285
• /
• 2020

An open-end winding (OEW) permanent magnet synchronous motor with dual inverters can synthesize large voltages for a motor with the same DC link voltage. This ability has the advantage of reducing the use of DC/DC boost converters or high voltage batteries. However, zero-sequence voltage (ZSV), which is caused by the difference in the combined voltage between the primary and secondary inverters, can generate a zero-sequence current (ZSC) that increases system losses. Among the methods for eliminating this phenomenon, combining voltage vector eliminated ZSV cannot be accomplished by the conventional Pulse Width Modulation(PWM) method. In this study, a PWM carrier generation method using functionalization to generate a switching pattern to suppress ZSC is proposed and applied to analyze the control influence of the center-zero vector in the switching sequence about the current ripple.

• 전기학회논문지
• /
• 제58권1호
• /
• pp.86-92
• /
• 2009

This paper presents development of 6kw ZVS(Zero Voltage Switching) boost converter by 4-parallel operation. To realize a high capacity converter with 6 kw, 4-parallel operation of 1.5kW unit module is proposed in this paper. To meet high ratio input to output voltage, isolated type booster converter is designed. To achieve ZVS operation of 4-switches of full bridge and protect a voltage overshoot caused by switch turn-off, simple active-clamp circuit is applied to the primary side. For parallel operation of 4-modules, master-slave control method is proposed to achieve input current sharing of 4-unit converter modules accurately. For performance tests, simulation is carried out. Also, load and experimental tests of the developed booster converter, 230Vdc/6kW, are carried out under various conditions. For field tests, the developed converter is applied for boosting a battery power to high DC_link voltage for a VSI inverter which starts a micro-turbine(MT) installed in vehicle and it's performance is verified through high speed motoring a MT up to tens of thousands of rpm.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권7호
• /
• pp.3363-3367
• /
• 2016

Background: Breast cancer (BC) is a major health issue worldwide as well as in Pakistan. All women belonging to any race, ethnicity or lineage are in danger of developing breast cancer. Significant factors influencing the development of breast malignancies are the genetic background, environmental conditions, reproductive parameters, the consequences of female hormones both intrinsic and extrinsic, alteration of immune status, and biologic determinants. Materials and Methods: Overall 150 biopsy proven patients were included in the study. Samples were submitted for histopathology and determination of estrogen and progesterone receptor expression and HER-2/neu status. Associations with other characteristics like age, tumor stage, node involvement, histological grade were also studied. Results: Mean age at presentation was 46.7 years. The majority had invasive ductal carcinoma, 100 (84.7%), and were in stage pT3, 54 (45.7%). Important relationships (P<0.05) were found among ER, PR positivity, and Her 2 neu overexpression. However, no noteworthy link was identified amongst ER, PR, Her 2 neu and tumor grade, stage, age, lymph node involvement except for the menopausal status. Conclusions: In summary, breast cancer patients featured an advanced stage of disease, more lymph node involvement, and moderately high grade tumors and with more estrogen, progesterone receptor and HER-2 positive tumors.

• Journal of Power Electronics
• /
• 제13권4호
• /
• pp.592-599
• /
• 2013

This paper investigates a new isolated single-phase AC-DC converter, which integrates a modified AC-DC buck-boost converter with a DC-DC forward converter. The front semi-stage is operated in discontinuous conduction mode (DCM) to achieve an almost unity power factor and a low total harmonic distortion of the input current. The rear semi-stage is used for step-down voltage conversion and electrical isolation. The front semi-stage uses a coupled inductor with the same winding-turn in the primary and secondary sides, which is charged in series during the switch-on period and is discharged in parallel during the switch-off period. The discharging time can be shortened. In other words, the duty ratio can be extended. This semi-stage can be operated in a larger duty-ratio range than the conventional AC-DC buck-boost converter for DCM operation. Therefore, the proposed converter is suitable for universal input voltage (90~264 $V_{rms}$) and a wide output-power range. Moreover, the voltage stress on the DC-link capacitor is low. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.

• 전력전자학회논문지
• /
• 제18권1호
• /
• pp.1-9
• /
• 2013

This paper proposes a ST(Switched Trans) quasi Z-source inverter using a Switched Trans Cell combing the characteristics of a Switched Inductor Cell and Trans. A DC link inductor of the conventional quasi Z-source inverter is alternated with Switched Trans Cell of the proposed ST quasi Z-source inverter. Trans Cell of the proposed method consists of one Trans and two diodes, and the proposed method has higher and more various boost function than the conventional quasi Z-source inverter by simply changing the turns ratio of primary and secondary of the Trans. The validity of the proposed ST Z-source inverter was confirmed by PSIM simulation and a DSP based experiment under the input voltage 48V and output phase voltage 30V. As a result, when compared with the traditional quasi Z-source inverter, the proposed method has the advantage of the low voltage stress under the same output voltage condition of the voltage.

• 한국식품영양과학회지
• /
• 제25권3호
• /
• pp.539-549
• /
• 1996

Large bowel cancer correlates tightly to dietary factors such as dietary fiber and fat. Dietary fiber prevents the large bowel cancer in different modes of action which depend upon physicochemical and fermentable properties. Water-soluble fiber is fermented easily by intestinal microbes producing short chain fatty acids ; in contrast, water-insoluble fiber occurs effectively more rapid transit time due to greater bulk of gut content, though it is unfermentable. Not only short chain fatty acid is utilized in the proximal and distal colon as primary energy source, but also it lowers pH in the colon to normalize cellular differentiation and helps to stimulate peri staltic movement by acting as an osmotic laxative. In particular, butyric acid may also regulate gene expression and cell growth, though it is an important respiratory fuel for the colonocyte. Since dietary fiber and non-digestible oligosaccharides are the major source of butyric acid, this provides a possible link between dietary fiber and oligosaccharide and prevention of large bowel cancer. But, as with many links between dietary fiber and large bowel cancer, a direct casual association has not been established. In addition, RDA of dietary fiber which is 20~25g/day for adult Japanese, appears to be reasonable for the defecation once daily and the prevention of large bowel cancer.

• 자원ㆍ환경경제연구
• /
• 제21권2호
• /
• pp.301-319
• /
• 2012

2012년부터 RPS 제도가 시행됨에 따라 신재생에너지 분야에서의 투자가 활발히 이루어질 것으로 예상된다. 신재생에너지를 통한 기업의 온실가스 감축투자는 장기적으로 기술진보와 국내 전력가격에도 영향을 미치는 중요한 요소이다. 한편, 국내에 온실가스 감축정책 수단으로 배출권거래제가 논의 중인 바, 유사한 성격의 두 제도가 기업의 환경투자 의사결정에 미치는 영향을 분석하도록 한다. 투자의 비가역성과 배출권 및 REC 가격의 불확실성을 고려하는 실물옵션 모형을 이용하여, 게이트웨이의 설정을 통한 배출권과 REC의 호환성이 보장될 때에 투자 인센티브를 분석하였다. 환경투자를 통해 온실가스 감축이 충분히 클 경우에는 투자에 대한 게이트웨이의 긍정적인 효과가 확인되는 것으로 나타났다. 신재생에너지 투자효과에 대한 보다 엄밀한 분석을 위하여 향후 발전사 데이터의 구축을 통해 실증분석이 추가로 이루어져야 할 것이다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권11호
• /
• pp.4720-4738
• /
• 2015

Proper management on user-driven virtual circuits (VCs) is essential for seamless operation of virtual networks. The Network Provisioning System (NPS) is useful software for creating user-driven VCs automatically and must take fault management into account for physical layer impairments on user-driven VCs. This paper addresses a user-driven and trusty protection management in an NPS with an open standard Network Service Interface (NSI), as a contribution to show how to implement the user-driven and trusty protection management required for user-driven VCs. In particular, it provides a RESTful web service Interface for Configuration and Event management (RICE) that enable management of a distinguished data and control plane VC status between Network Service Agents (NSAs) in the event of a node or link fault and repair in a domain. This capability represents a contribution to show how network and protection events in a domain can be monitored between NSAs (NPSs with the NSI) in multiple domains. The implemented NPS controls and manages both the primary and backup VC with disjoint path in a user-driven manner. A demonstration to verify RICE API's capability is addressed for the trusty protection in the dynamic VC network.