• Nuclear Engineering and Technology
• /
• v.44 no.3
• /
• pp.311-322
• /
• 2012

Since the crisis at the Fukushima plants, severe accident progression during a station blackout accident in nuclear power plants is recognized as a very important area for accident management and emergency planning. The purpose of this study is to investigate the comparative characteristics of anticipated severe accident progression among the three typical types of nuclear reactors. A station blackout scenario, where all off-site power is lost and the diesel generators fail, is simulated as an initiating event of a severe accident sequence. In this study a comparative analysis was performed for typical pressurized water reactor (PWR), boiling water reactor (BWR), and pressurized heavy water reactor (PHWR). The study includes the summarization of design differences that would impact severe accident progressions, thermal hydraulic/severe accident phenomenological analysis during a station blackout initiated-severe accident; and an investigation of the core damage process, both within the reactor vessel before it fails and in the containment afterwards, and the resultant impact on the containment.

• Journal of Korean Society of Transportation
• /
• v.5 no.2
• /
• pp.5-18
• /
• 1987

Buses arrive at a traffic intersection later than passenger cars by the amount of dwell time at previous bus stops. This late arrival of buses affects the total passenger delay at intersections especially in the street carrying large bus volume. The bus progression signal system in which the signal offset is given in favor of bus platoons was applied in the case area of Kangnam street in Seoul, and various effects were analyzed using the TRANSYT-7F simulation model. It was observed that the total passenger delay can be reduced significantly if the bus progression signal system is applied, and the most effective bus priority treatment is proved to be the bus progression signal system installed with exclusive bus lanes.

• BMB Reports
• /
• v.36 no.1
• /
• pp.60-65
• /
• 2003

Cancer is frequently considered to be a disease of the cell cycle. As such, it is not surprising that the deregulation of the cell cycle is one of the most frequent alterations during tumor development. Cell cycle progression is a highly-ordered and tightly-regulated process that involves multiple checkpoints that assess extracellular growth signals, cell size, and DNA integrity. Cyclin-dependent kinases (CDKs) and their cyclin partners are positive regulators of accelerators that induce cell cycle progression; whereas, cyclin-dependent kinase inhibitors (CKIs) that act as brakes to stop cell cycle progression in response to regulatory signals are important negative regulators. Cancer originates from the abnormal expression of activation of positive regulators and functional suppression of negative regulators. Therefore, understanding the molecular mechanisms of the deregulation of cell cycle progression in cancer can provide important insights into how normal cells become tumorigenic, as well as how cancer treatment strategies can be designed.

• Journal of Korean Society of Transportation
• /
• v.10 no.2
• /
• pp.25-42
• /
• 1992

The purpose of this paper is to construct a model to compute a progression adjustment factor on a signalized network. In a way to construct the model, a simulation method is introduced and the TRAF-NETSIM is used as a tool of simulation. The structure of the network chooses an urban arterial network so as to measure the effect of progression and compute average stopped delay on each link. A regression model is constructed by using the results of the simulation. The stepwise variable selection in the regression model in used. The findings of this paper are as follows: i)The secondary queue and platoon ratio are sensitive to the values of the progression adjustment factor ii) The continuous model can practically reflect on various situations in the real world. The platoon adjustment factor can be computed by this model and the data required for this model can be easily obtained in the field.

• Journal of Ginseng Research
• /
• v.21 no.1
• /
• pp.49-52
• /
• 1997

There are many mechanisms that mediate progression of renal injury, such as abnormalities of nitric oxide (NO) regulation, increased Platelet aggregatlon, and oxygen free radical injury. Ginseng has been known to have NO dependent vasorelaxant effect and antioxidant effect, also inhibit thrombin stimulated platelet aggregation. And these effects of ginseng may have some roles in prevention of renal injury. So we studied 24 patients with mild pathologic proteinuria and hypertension to evaluate the effect of ginseng on progression of renal injury. After 1 month treatment, creatinine clearance was significantly increased especially in the patient group with normal serum creatinine level without specific side effect. The result of this study suggest that ginseng may pre vent or retard the progression of renal injury especially in early stage.

• The Journal of the Korean dental association
• /
• v.49 no.3
• /
• pp.153-158
• /
• 2011

Oral precancerous lesion is a morphologically altered tissue in which oral cancer is more likely to occur than is apparently normal counterpart. As dentists always do oral examination and dental treatment, with fundamental knowledge and attention of this lesion, it is relatively easy to find one. If followed by proper treatment and management, it is possible to minimize its oral cancer progression, or at least delay it. Even if it were to progress to oral cancer, very early detection is possible. However, no specific biomarkers are present at the moment that could reveal oral precnacerous lesion that is high risk of oral cancer progression. Since early detection of oral cancer followed by treatment could show good prognosis with just a simple ablative surgery. Dentists should also instruct people to avoid risk factor related oral cancer progression and take natural compound having anticancer effect. Hereby, As a primary care givers, dentists play an important role in prevention of oral cancer.

• Smart Structures and Systems
• /
• v.23 no.2
• /
• pp.173-184
• /
• 2019

The main objective of this study is to evaluate the true fracture energy and monitor the damage progression in steel fibre reinforced concrete (SFRC) specimens using acoustic emission (AE) features. Four point bending test is carried out using pre-notched plain and fibre reinforced (0.5% and 1% volume fraction) - concrete under monotonic loading. AE sensors are affixed at different locations of the specimens and AE parameters such as rise time, AE energy, hits, counts, amplitude and duration etc. are obtained. Using the captured and processed AE event data, fracture process zone is identified and the true fracture energy is evaluated. The AE data is also employed for tracing the damage progression in plain and fibre reinforced concrete, using both parametric- and signal- based techniques. Hilbert - Huang transform (HHT) is used in signal based processing for evaluating instantaneous frequency of the acoustic events. It is found that the appropriately processed and carefully analyzed acoustic data is capable of providing vital information on progression of damage on different types of concrete.

• Childhood Kidney Diseases
• /
• v.25 no.1
• /
• pp.1-7
• /
• 2021

Chronic kidney disease (CKD) in children is associated with various complications, including poor growth and development, mineral bone disorder, cardiovascular disease, kidney failure, and mortality. Slowing down the progression of CKD is important since CKD is often not curable. Prospective cohort studies have been conducted to understand the progression and outcomes of CKD in children, and these studies have identified non-modifiable and modifiable risk factors. Recognition of known risk factors and early intervention are important to delay the progression of kidney function decline in children.

• The Journal of Korean Medicine
• /
• v.44 no.3
• /
• pp.102-116
• /
• 2023

Objectives: To provide a case report of effective use of Korean herbal medicine treatment to reduce the development and progression of normal-tension glaucoma(NTG). Methods: This case involved a 52-year-old patient who had a history of excimer laser surgery at the age of 25 and was using prescriptions such as Cosopts2 and Xalatan for eye drops. We treated this patient with Korean herbal medicine treatment for 2 years and assessed the progression of NTG based on the optical coherence tomography test results that he recevied at the ophthalmology clinic every 6 months. Results: During the two years of treatment with Korean herbal medicine, it was observed that the progression of NTG was halted. However, after discontinuing the Korean herbal treatment, the progression resumed. Conclusion: Korean herbal medicine treatment was found to be effective in treating normal tension glaucoma, and a minimum treatment period of two years is necessary for an accurate evaluation of NTG.

• Korean Journal of Radiology
• /
• v.25 no.8
• /
• pp.698-705
• /
• 2024

Ductal carcinoma in situ (DCIS) accounts for approximately 30% of new breast cancer diagnoses. However, our understanding of how normal breast tissue evolves into DCIS and invasive cancers remains insufficient. Further, conclusions regarding the mechanisms of disease progression in terms of histopathology, genetics, and radiology are often conflicting and have implications for treatment planning. Moreover, the increase in DCIS diagnoses since the adoption of organized breast cancer screening programs has raised concerns about overdiagnosis and subsequent overtreatment. Active monitoring, a nonsurgical management strategy for DCIS, avoids surgery in favor of close imaging follow-up to de-escalate therapy and provides more treatment options. However, the two major challenges in active monitoring are identifying occult invasive cancer and patients at risk of invasive cancer progression. Subsequently, four prospective active monitoring trials are ongoing to determine the feasibility of active monitoring and refine the patient eligibility criteria and follow-up intervals. Radiologists play a major role in determining eligibility for active monitoring and reviewing surveillance images for disease progression. Trial results published over the next few years would support a new era of multidisciplinary DCIS care.