• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.152-152
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• 2022

Only employing historical data limits the estimation of the full distribution of probable Tropical Cyclone (TC) risk due to the insufficiency of samples. Addressing this limitation, this study introduces a semi-physical TC rainfall model that produces spatially and temporally resolved TC rainfall data to improve TC risk assessments. The model combines a statistical-based track model based on the Markov renewal process to produce synthetic TC tracks, with a physics-based model that considers the interaction between TC and the atmospheric environment to estimate TC rainfall. The simulated data from the combined model are then fitted to a probability distribution function to compute the spatially heterogeneous risk brought by landfalling TCs. The methodology is employed in South Korea as a case study to be able to implement a country-scale-based vulnerability inspection from damaging TC impacts. Results show that the proposed model can produce TC tracks that do not only follow the spatial distribution of past TCs but also reveal new paths that could be utilized to consider events outside of what has been historically observed. The model is also found to be suitable for properly estimating the total rainfall induced by landfalling TCs across various points of interest within the study area. The simulated TC rainfall data enable us to reliably estimate extreme rainfall from higher return periods that are often overlooked when only the historical data is employed. In addition, the model can properly describe the distribution of rainfall extremes that show a heterogeneous pattern throughout the study area and that vary per return period. Overall, results show that the proposed approach can be a valuable tool in providing sufficient TC rainfall samples that could be an aid in improving TC risk assessment.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.468-471
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• 2009

Objective : The adolescent presentation of tethered cord syndrome (TCS) is well-recognized, but continues to pose significant diagnostic and management controversies. The authors conducted a retrospective study of clinical outcomes after surgical intervention in 24 school-aged children, adolescents, and young adults with TCS. Methods : All 83 patients with a lipomyelomeningocele (LMMC) underwent untethering surgery for caudal cord tethering between 1987 and 2007. The clinical charts and follow-up data were reviewed. Of these patients, 24 school-aged children, adolescents, and young adults with TCS were studied with respect to the clinical, radiologic, pathologic features, and surgical outcomes. Results : Untethering procedures were performed in 24 patients (age range, 7-25 years) for TCS of various origins (lipoma, lipomyelomeningocele, and tight filum terminale). Specific circumstances involving additional tugging of the already tight conus, and direct trauma to the back precipitated the onset of symptom in 50% of the patients. Diffuse and non-dermatomal leg pain, often referred to the anorectal region, was the most common presenting symptom. Progressive sensorimotor deficits in the lower extremities, as well as bladder and bowel dysfunction, were also common findings, but progressive foot and spinal deformities were noted less frequently. The most common tethered lesions were intradural lipomas, thickened filum and fibrous band adhesions into the placode sac. The surgical outcome was gratifying in relation to pain and motor weakness, but disappointing with respect to resolution of bowel and bladder dysfunction. Of the 24 patients with TCS, pre-operative deficits improved after surgery in 14 (58.3%). remained stable in 8 (33.4%). and worsened in 2 (8.3%). Conclusion : The pathologic lesions of tethered cord syndrome in school-aged children, adolescents, and young adults, are mostly intradural lipomas and tight filum. It is suggested that the degree of cord traction results in neurologic dysfunction in late life due to abnormal tension, aggravated by trauma or repeated tugging of the conus during exercise. Early diagnosis and adequate surgical release might be the keys to the successful outcome in school-aged children, adolescents, and young adults with TCS.

• Atmosphere
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• v.24 no.3
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• pp.283-301
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• 2014

In 2010, only 14 tropical cyclones (TCs) were generated over the western North Pacific (WNP), which was the smallest since 1951. This study summarizes characteristics of TCs generated in 2010 over the WNP and investigates the causes of the record-breaking TC genesis. A long-term variation of TC activity in the WNP and verification of official track forecast in 2010 are also examined. Monthly tropical sea surface temperature (SST) anomaly data reveal that El Ni$\tilde{n}$o/Southern Oscillation (ENSO) event in 2010 was shifted from El Ni$\tilde{n}$o to La Ni$\tilde{n}$a in June and the La Ni$\tilde{n}$a event was strong and continued to the end of the year. We found that these tropical environments leaded to unfavorable conditions for TC formation at main TC development area prior to May and at tropics east of $140^{\circ}E$ during summer mostly due to low SST, weak convection, and strong vertical wind shear in those areas. The similar ENSO event (in shifting time and La Ni$\tilde{n}$a intensity) also occurred in 1998, which was the second smallest TC genesis year (16 TCs) since 1951. The common point of the two years suggests that the ENSO episode shifting from El Ni$\tilde{n}$o to strong La Ni$\tilde{n}$a in summer leads to extremely low TC genesis during La Ni$\tilde{n}$a although more samples are needed for confidence. In 2010, three TCs, DIANMU (1004), KOMPASU (1007) and MALOU (1009), influenced the Korean Peninsula (KP) in spite of low total TC genesis. These TCs were all generated at high latitude above $20^{\circ}N$ and arrived over the KP in short time. Among them, KOMPASU (1007) brought the most serious damage to the KP due to strong wind. For 14 TCs in 2010, mean official track forecast error of the Korea Meteorological Administration (KMA) for 48 hours was 215 km, which was the highest among other foreign agencies although the errors are generally decreasing for last 10 years, suggesting that more efforts are needed to improve the forecast skill.

• Journal of Korean Academy of Nursing
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• v.48 no.3
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• pp.362-374
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• 2018

Purpose: This study aimed to develop a triage competency scale (TCS) for emergency nurses, and to evaluate its validity and reliability. Methods: Preliminary items were derived based on the attributes and indicators elicited from a concept analysis study on triage competency. Ten experts assessed whether the preliminary items belonged to the construct factor and determined the appropriateness of each item. A revised questionnaire was administered to 250 nurses in 18 emergency departments to evaluate the reliability and validity of the scale. Data analysis comprised item analysis, confirmatory factor analysis, contrasted group validity, and criterion-related validity, including criterion-related validity of the problem solving method using video scenarios. Results: The item analysis and confirmatory factor analysis yielded 5 factors with 30 items; the fit index of the derived model was good (${\chi}^2/df=2.46$, Root Mean squared Residual=.04, Root Mean Squared Error of Approximation=.08). Additionally, contrasted group validity was assessed. Participants were classified as novice, advanced beginner, competent, and proficient, and significant differences were observed in the mean score for each group (F=6.02, p=.001). With reference to criterion-related validity, there was a positive correlation between scores on the TCS and the Clinical Decision Making in Nursing Scale (r=.48, p<.001). Further, the total score on the problem solving method using video scenarios was positively correlated with the TCS score (r=.13, p=.04). The Cronbach's ${\alpha}$ of the final model was .91. Conclusion: Our TCS is useful for the objective assessment of triage competency among emergency nurses and the evaluation of triage education programs.

• Atmosphere
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• v.21 no.1
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• pp.45-55
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• 2011

A definition on the tropical cyclone (TC) that influenced the Korean Peninsula (KP), the KP-influence TC, is widely used in the TC communities, but its criterion is not clear mainly due to the ambiguity and subjectiveness of the term such as 'influence', which led to the inconsistent TC statistical analysis. This study suggests a definition and criterion on the TC approaching to the KP (KP-approach TC) additionally, which is more obvious and objective than the KP-influence TC. In this study, the criterion on the KP-approach TC is determined when the TC's center from the RSMC best track data encounters the box areas of $28^{\circ}N{\sim}40^{\circ}N$ and $120^{\circ}E{\sim}138^{\circ}E$. The range is chosen by finding a minimum area that includes all official KP-influence TCs except three TCs that affected the KP as a tropical depression (TD). Statistical analysis reveals that, among total 1,537 TCs that occur in the western North Pacific during 1951-2008, the KP-approach TC was 472, the KP-influence TC was 187, and the KP-landfall TC was 87. August was the month that the largest TCs approach and influence to the KP. Finally, this paper suggests to determine the KP-influence TC by the strong wind and heavy rain advisories in the KP based on the observation after the storm's passage.

• Atmosphere
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• v.34 no.2
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• pp.97-106
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• 2024

The seasonal forecast skill of tropical cyclones (TCs) in the Northern Hemisphere from the Korea Meteorological Administration (KMA) Global Seasonal Forecast System version 6 (GloSea6) hindcast has been verified for the period 1993 to 2016. The operational climate prediction system at KMA was upgraded from GloSea5 to GloSea6 in 2022, therefore further validation was warranted for the seasonal predictability and variability of this new system for TC forecasts. In this study, we examine the frequency, track density, duration, and strength of TCs in the North Indian Ocean, the western North Pacific, the eastern North Pacific, and the North Atlantic against the best track data. This methodology follows a previous study covering the period 1996 to 2009 published in 2020. GloSea6 indicates a higher frequency of TC generation compared to observations in the western North Pacific and the eastern North Pacific, suggesting the possibility of more TC generation than GloSea5. Additionally, GloSea6 exhibits better interannual variability of TC frequency, which shows relatively good correlation with observations in the North Atlantic and the western North Pacific. Regarding TC intensity, GloSea6 still underestimates the minimum surface pressures and maximum wind speeds from TCs, as is common among most climate models due to lower horizontal resolutions. However, GloSea6 is likely capable of simulating slightly stronger TCs than GloSea5, partly attributed to more frequent 6-hourly outputs compared to the previous daily outputs.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1767-1770
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• 2003

This paper proposes an efficient network architecture for reflective memory system (RMS). Using this architecture, the time for broadcasting a shared-data to all nodes can be significantly shortened. The device named topology conversion switch (TCS) is implemented to realize the network architecture. The implemented TCS is applied to the ethernet based real time control network (ERCnet) to evaluate the performance.

• Ocean and Polar Research
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• v.34 no.1
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• pp.29-35
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• 2012

We investigated the interannual relationship between chlorophyll concentrations in the western North Pacific and tropical cyclones (TCs) in the western North Pacific by analyzing data collected for >12 years. Despite the short-term scale (2~3 weeks) in the contribution of tropical cyclones to phytoplankton, the current study revealed that the long-term chlorophyll variability in the western North Pacific is profoundly related to long-term variability in the frequency of TCs. It was also found that the Pacific decadal oscillation (PDO) tends to control such relationships between the 2 bio-physical systems. This result suggests a significant climatic relationship between TC activity and marine phytoplankton, and also suggests the possibility of more accurate estimations of primary production in the western North Pacific.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1025-1028
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• 2009

고속도로의 다양한 주행특성으로는 과속하는 차량, 휴게소나 기타목적의 이용차량, 운전자의 습관이나 피로도등이 있는데 이에 따라 고속도로 주행시간에 차이가 나타난다. 하지만 현재에는 이러한 특성을 고려하지 않고 통행시간 분류가 되고 있어 정확성과 신뢰성을 보장하지 못하고 있는 실정이다. 이에 본 연구에서는 데이터 분포에 따른 해석을 통하여 TCS데이터의 특성을 고려 할 수 있는 Fuzzy c-means 알고리즘과 단순히 임의의 초기값으로 분류하는 K-means와의 비교를 통해서 주행특성을 고려한 클러스터링 기법이 경우에 따라서 더 효과적이고 신뢰성 있는 분류방법이 될 수 있음을 증명하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.1-10
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• 2010

Safety improvement has been a continuous challenge, especially at toll gate of express highway where traffic conflict often occurs due to frequent lane change by drivers of "Hi-pass" lane and regular "TCS" lane. As a part of research on safety at toll gate, this study videotaped traffic conflict data between vehicles using centrally located "Hi-pass" lane and regular "TCS" lane and analyzed accident risk. According to the correlation analysis of vehicle speed, relative vehicle speed, and sudden vehicle deceleration rate due to traffic conflict, when the relative vehicle speed between centrally located "Hi-pass" lane and regular "TCS" lane increases, sudden vehicle deceleration rate also increases. One of the findings is that centrally located "Hi-pass" lane at toll gate shows different location for traffic conflict, and frequency of traffic conflict and the relative vehicle speed was also different based on vehicle lane use. TA (Time to Accident) analysis shows that accident rate is high at toll gate where Hipass lane is installed in center lane, when the occurrence of sudden vehicle deceleration and deceleration time of vehicles rise for vehicles on "Hi-pass" lane. Furthermore, if the expressway entrance/exit point is closely located to toll gate, TA showed a low value. Thus, it is necessary to reduce the relative vehicle speed in order to improve safety. The Study presents reduction of the relevant vehicular speed and prevention of accidents at the centrally installed "Hi-pass" lane as an important strategy for safety improvement at toll gate.