• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.2
• /
• pp.152-158
• /
• 2007

Most of experimental visualizations and numerical results on the flow field separated form a leading edge around an unsteady foil show a continuous streakline from the leading edge and large reverse flow between the streakline and the suction surface. However, they have not exactly clarified yet the dynamic behavior of vortices separated from the leading edge because separation around an unsteady foil is very complicated phenomenon due to many parameters. In the present study the flow fields around pitching foils have been visualized by using a Schlieren method with a high speed camera in a wind tunnel at low Reynolds number regions. It has been observed that small vortices are shed discretely from the leading and trailing edge and that they stand in line on the integrated streakline of separation shear layer. By counting vortices in the VTR frames it was clarified that the number of vortex shedding from the leading and trailing edge during one pitching cycle strongly depends on the non-dimensional pitching rate. Futhermore the vortices moving up to the leading edge on the suction surface of the pitching foil are visualized. They play an important role to balance the number of vortex shedding from both edges.

• Ocean and Polar Research
• /
• v.28 no.2
• /
• pp.209-214
• /
• 2006

The East Sea Branch (ESB) of KORDI will be launched in 2008. She will take a role of monitoring the sea surface topography and temperature by satellites, short- and long-term sea levels by tide gauges, coastal currents and open-sea circulation by setting up coastal radars and mooring current-meters and acoustic equipments, as well as monitoring nearshore processes, coastal erosion and water pollution. A basic program of coastal zone management will help ocean-policy makers to set up right decisions based upon scientific background of the regional data in the East Sea. Networking among the neighboring countries around the sea will supply more useful information not only for experts but also for ordinary vacationers or fishermen. In order for this program to be successfully settled down during the next decade, it is necessary for a leader to have the right vision to attract more experts from global brain pools and to manage the ESB as a leading-edge observatory in the world. Details about this leading-edge operational program are introduced in the text.

• Journal of Korea Technology Innovation Society
• /
• v.1 no.3
• /
• pp.402-418
• /
• 1998

This study attempts to analysis of the 1'ole and B/C(Benefict/Cost)of National Supported Supercomputing Center in process of the promotion for informatization in Korea. ETRI Supercomputing Center, as National Supported Supercomputing Center, was established in 1967 as a laboratory of KIST(Korea Institute of Science and Technology). ETRI Supercomputer Center have acted a leading role as National HPCC(High Performance Computing and Communication) in Korea. The result of B/C analysis of En Supercomputer Center showed that it is twenty times benefit as many as cost for the last 30 years. As soon as possible, it was Suggested that ETRI Supercomputer Center must be developed as National Supercomputing Center(NSC).

• Toxicological Research
• /
• v.26 no.4
• /
• pp.245-252
• /
• 2010

Epithelial-mesenchymal transition (EMT) is a complex process in which epithelial cells acquire the characteristics of invasive mesenchymal cells. EMT has been implicated in cancer progression and metastasis as well as the formation of many tissues and organs during development. Epithelial cells undergoing EMT lose cell-cell adhesion structures and polarity, and rearrange their cytoskeletons. Several oncogenic pathways such as transforming growth factor (TGF)-$\beta$, Wnt, and Notch signaling pathways, have been shown to induce EMT. These pathways have activated transcription factors including Snail, Slug, and the ZEB family which work as transcriptional repressors of E-cadherin, thereby making epithelial cells motile and resistant to apoptosis. Mounting evidence shows that EMT is associated with cell invasion and tumor progression. In this review, we summarize the characteristic features of EMT, pathways leading to EMT, and the role of EMT in cell invasion. Three topics are addressed in this review: (1) Definition of EMT, (2) Signaling pathways leading to EMT, (3) Role of EMT in cell invasion. Understanding the role of EMT in cell invasion will provide valuable information for establishing strategies to develop anti-metastatic therapeutics which modulate malignant cellular processes mediated by EMT.

• Kidney Research and Clinical Practice
• /
• v.35 no.2
• /
• pp.69-77
• /
• 2016

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease, and its pathogenesis is complex and has not yet been fully elucidated. Abnormal glucose and lipid metabolism is key to understanding the pathogenesis of DN, which can develop in both type 1 and type 2 diabetes. A hallmark of this disease is the accumulation of glucose and lipids in renal cells, resulting in oxidative and endoplasmic reticulum stress, intracellular hypoxia, and inflammation, eventually leading to glomerulosclerosis and interstitial fibrosis. There is a growing body of evidence demonstrating that dysregulation of 50 adenosine monophosphate-activated protein kinase (AMPK), an enzyme that plays a principal role in cell growth and cellular energy homeostasis, in relevant tissues is a key component of the development of metabolic syndrome and type 2 diabetes mellitus; thus, targeting this enzyme may ameliorate some pathologic features of this disease. AMPK regulates the coordination of anabolic processes, with its activation proven to improve glucose and lipid homeostasis in insulin-resistant animal models, as well as demonstrating mitochondrial biogenesis and antitumor activity. In this review, we discuss new findings regarding the role of AMPK in the pathogenesis of DN and offer suggestions for feasible clinical use and future studies of the role of AMPK activators in this disorder.

• Journal of the Korean Society of School Health
• /
• v.6 no.2
• /
• pp.76-88
• /
• 1993

The purpose of this study is to analyze correlation between the view of teaching profession and the role performance of school nurse. For the achievement of this purpose 188 school nurses in Tae-Gu city and Kyung-Sang Buk-Do are randomly selected in 1992. Major findings of this study were as follows: 1) Role performance of the school nurse showed school health room, health planning, health education, disease control, environment sanitation and management of health organization, in the order named. 2) Degree of school nurse role performance showed 84.7% of the total respondents as highly. 3) Relationship between the view of teaching profession and the role performance was statistically significant correlation. 4) Role performance of school nurse was explained 29.4% by the view of teaching profession (public life, human relation & leading student) of the total variables.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.9 no.2
• /
• pp.23-33
• /
• 2014

This paper aims at delivering significant implications to high-tech startups by visualizing the implementation process of leading KOSDAQ listed companies's business model. This paper founded two meaningful outcomes; first, hish-tech starts-up make a clear direction of implementing intangible business model in real business, second, targeting the role model of benchmarking business model among leading companies, by linking common feature between high-tech starts-up and leading KOSDAQ listed venutures sharing one of Key performance indexes falls on viable business model. The research results of visualizing the implementation of leading KOSDAQ listed ventures' business model shows three major implications. First, business model indicates not just simple logic of creating and delivering values, but more shows CEO leading management vehicle. Second, business model represents the multi-dimension process itself of integrating in and out company's core assets and competencies initiated by CEO. Third, financial outcomes of business model is automatic result of implementing on setting target customer, creating value, and delivering it rather than planned strategically. Fourth, the focal points of implementing business model falls on collecting real information from business sites.

• The Korean Journal of Physiology and Pharmacology
• /
• v.14 no.6
• /
• pp.413-417
• /
• 2010

To understand the function of edges in perception of moving objects, we defined four questions to answer. Is the focus point in visual motion detection of a moving object: (1) the body or the edge of the object, (2) the leading edge or trailing edge of the object, (3) different in scotopic, mesopic and photopic luminance levels, or (4) different for colored objects? We measured the Optomotor Response (OMR) and Edge Triggering Response (ETR) of goldfish. We used a square and sine wave patterns with black and red stripes and a square wave pattern with black and grey stripes to generate OMR's and ETR's in the goldfish. When we used black and red stripes, the black leading edges stimulated an ETR under scotopic conditions, red leading edges stimulated an ETR under photopic conditions, and both black and red leading edges stimulated an ETR under mesopic luminance levels. For black and gray stripes, only black leading edges stimulated an ETR in all three light illumination levels. We observed less OMR and ETR results using the sine wave pattern compared to using the square wave pattern. From these results, we deduced that the goldfish tend to prefer tracking the leading edge of the pattern. The goldfish can also detect the color of the moving pattern under photopic luminance conditions. We decided that ETR is an intriguing factor in OMR, and is suitable as a method of behavioral measurement in visual system research.

• Proceedings of the Korean Biophysical Society Conference
• /
• 2001.06a
• /
• pp.25-25
• /
• 2001

Diabetes is the leading cause of end-stage renal disease worldwide. In Korea, diabetic kidney disease accounted for 39％ of all new dialysis patients in 1998. Diabetic nephropathy is characterized by glomerular hyperfiltration, albuminuria, and expansion of glomerular mesangium. Since glomerular mesangial cells regulate glomerular filtration rates and are capable of producing extracellular matrix (ECM) proteins, the functional abnormalities of mesangial cells under diabetic milieu play an important role in the development and progression of diabetic nephropathy.(omitted)

• Toxicological Research
• /
• v.35 no.3
• /
• pp.209-214
• /
• 2019

Cancer is the leading cause of mortality worldwide. In cancer progression, sex hormones and their receptors are thought to be major factors. Many studies have reported the effects of estrogen and estrogen receptors (ERs) in cancer development and progression. Among them, G protein-coupled estrogen receptor (GPER), a G protein-coupled receptor, has been identified as an estrogen membrane receptor unrelated to nuclear ER. The mechanism of GPER, including its biological action, function, and role, has been studied in various cancer types. In this review, we discuss the relation between GPER and estrogen or estrogen agonists/antagonists and cancer progression.