• Journal of the Korean earth science society
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• v.33 no.2
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• pp.148-161
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• 2012

The intensive observation (ProbeX-2010) with 6-hour launches of radiosonde was performed over Seoul metropolitan area (Dongducheon, Incheon Airport, and Yangpyeong) from 13 Aug. to 3 Sep. 2010. Five typical heavy rainfall patterns occurred consecutively which are squall line, stationary front, remote tropical cyclone (TC), tropical depression, and typhoon patterns. On 15 Aug. 03 KST, when squall line developed over Seoul metropolitan area, dry mid-level air was drawn over warm and moist low-level air, inducing strong convective instability. From 23 to 26 Aug and from 27 to 29 Aug. Rainfall event occurred influenced by stationary front and remote TC, respectively. During the stationary frontal rainy period, thermal instability was dominant in the beginning stage, but dynamic instability became strong in the latter stage. Especially, heavy rainfall occurred on 25 Aug. when southerly low level jet formed over the Yellow Sea. During the rainy period by the remote TC, thermal and dynamic instability sustained together. Especially, heavy rainfall event occurred on 29 Aug. when the tropical air with high equivalent potential temperature (>345 K) occupied the deep low-middle level. On 27 Aug. and 2 Sep. tropical depression and typhoon Kompasu affected Seoul metropolitan area, respectively. During these events, dynamic instability was very strong.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.604-610
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• 2006

Background: Recent improvements in interventional procedure and medical therapy for congestive heart failure result in an increase of number of patients with ischemic cardiomyopathy considered for coronary artery bypass grafting. We retrospectively review the results of CABG in these patients with decreased LV function to know the early and mid-term follow-up results. Material and Method: Between January 2001 and June 2005, 1,143 patients underwent coronary artery bypass grafting and 144 of these patients had preoperative left ventricular function of equal to or less than 35% ${(LVEF{\leq}\;35%)}$. There were off-pump coronary artery bypass grafting (OPCAB) in 66 cases (45.8%), on-pump beating heart coronary artery bypass grafting in 34 cases (23.6%) and conventional coronary artery bypass grafting in 44 cases (30.6%). The combined operations including mitral annuloplasty were 48 cases in thirty five patients (24.3%). Result: The mean number of dstal anastomosis were $3.5{\pm}1.3$. The median postoperative duration of stay in intensive care unit and hospital was 2 days and 8 days, respectively. There were 6 early death (4.2%) and causes of deaths were ventricular tachycardia in 5 patients, small bowel infarction in one patient. Mean follow-up time was $21{\pm}14$ months $(4{\sim}54\;months)$. The 1-year was $95{\pm}2%$ and 3-year survival rate was $83{\pm}7%$, the 1-year and 3-year cardiac event-free survival were ${88{\pm}3%\;and\;69{\pm}7%}$, respectively. Conclusion: Based on satisfactory early and mid-term results in our study, CABG should be carried out as actively as possible in patients with ischemic cardiomyopathy. Postoperative aggressive management for ventricular arrhythmia would be helpful for better results.

• Journal of Oral Medicine and Pain
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• v.34 no.4
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• pp.397-407
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• 2009

The aim of the study was to evaluate psychosocial impact of non-dental chronic orofacial pain (OFP) on daily living using the graded chronic pain (GCP) scale. It is also investigated the clinical profile such as demographics, event related to initiation of OFP and prior treatments for patients. During previous 6 months since September 2008, 572 patients (M:F=1:1.5, mean age=34.7 years) with non-dental OFP attended university-based specialist orofacial pain clinic (Dankook University Dental Hospital, Cheonan) to seek care although 63% of them already experienced related treatment for their OFP problem. They visited the most frequently general dental practitioner and orthopedic doctors due to their pain problem and medication was the most commonly employed modality. Most of the patients (89.2%) had TMD and the most common related event to initiation of their pain was trauma, followed by dental treatment. Almost half of the patients (46%) suffered from chronic pain(${\geq}6\;M$) and 40% of them exhibited relatively high disability due to chronic OFP. GCP pain intensity and disability days were significantly different for age and diagnosis (p<0.05) but not for gender and duration. GCP grades were affected by all the factors including gender, age, pain duration and diagnosis.(p=0.000) Female gender, elders, and long lasting pain were closely related to high disability. The patients with neuropathic Pain and mixed OFP rather than TMD were graded as being highly disabled. Conclusively, a considerable percentage of chronic OFP patients reports high pain-related disability in their daily, social and work activity, which suggest a need for psychosocial support and importance of earlier referral for appropriate diagnosis and tailored management.

• Journal of Intelligence and Information Systems
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• v.18 no.2
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• pp.47-60
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• 2012

Video data comes in the form of the unstructured and the complex structure. As the importance of efficient management and retrieval for video data increases, studies on the video parsing based on the visual features contained in the video contents are researched to reconstruct video data as the meaningful structure. The early studies on video parsing are focused on splitting video data into shots, but detecting the shot boundary defined with the physical boundary does not cosider the semantic association of video data. Recently, studies on structuralizing video shots having the semantic association to the video scene defined with the semantic boundary by utilizing clustering methods are actively progressed. Previous studies on detecting the video scene try to detect video scenes by utilizing clustering algorithms based on the similarity measure between video shots mainly depended on color features. However, the correct identification of a video shot or scene and the detection of the gradual transitions such as dissolve, fade and wipe are difficult because color features of video data contain a noise and are abruptly changed due to the intervention of an unexpected object. In this paper, to solve these problems, we propose the Scene Detector by using Color histogram, corner Edge and Object color histogram (SDCEO) that clusters similar shots organizing same event based on visual features including the color histogram, the corner edge and the object color histogram to detect video scenes. The SDCEO is worthy of notice in a sense that it uses the edge feature with the color feature, and as a result, it effectively detects the gradual transitions as well as the abrupt transitions. The SDCEO consists of the Shot Bound Identifier and the Video Scene Detector. The Shot Bound Identifier is comprised of the Color Histogram Analysis step and the Corner Edge Analysis step. In the Color Histogram Analysis step, SDCEO uses the color histogram feature to organizing shot boundaries. The color histogram, recording the percentage of each quantized color among all pixels in a frame, are chosen for their good performance, as also reported in other work of content-based image and video analysis. To organize shot boundaries, SDCEO joins associated sequential frames into shot boundaries by measuring the similarity of the color histogram between frames. In the Corner Edge Analysis step, SDCEO identifies the final shot boundaries by using the corner edge feature. SDCEO detect associated shot boundaries comparing the corner edge feature between the last frame of previous shot boundary and the first frame of next shot boundary. In the Key-frame Extraction step, SDCEO compares each frame with all frames and measures the similarity by using histogram euclidean distance, and then select the frame the most similar with all frames contained in same shot boundary as the key-frame. Video Scene Detector clusters associated shots organizing same event by utilizing the hierarchical agglomerative clustering method based on the visual features including the color histogram and the object color histogram. After detecting video scenes, SDCEO organizes final video scene by repetitive clustering until the simiarity distance between shot boundaries less than the threshold h. In this paper, we construct the prototype of SDCEO and experiments are carried out with the baseline data that are manually constructed, and the experimental results that the precision of shot boundary detection is 93.3% and the precision of video scene detection is 83.3% are satisfactory.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.193-202
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• 2015

In this study, a long term monitering of nonpoint source pollution runoff is conducted at the area of transportation related and EMCs(Event Mean Concentrations) in terms of water quality items, such as BOD, $COD_{Mn}$, SS, T-N and T-P are determined for each not only runoff event and but also observation site. On the other hands, SWMM(Storm Water Management Model) model is constructed using the data collected in the transportation areas selected. Model calibration and verification of SWMM is carried out based on the data collected. And simulated EMCs was compared with observed EMCs by monitoring and prior studies. SWMM applicability estimation was Using the compared result. The results of simulation showed that BOD 5.787 ~ 14.475 mg/L, $COD_{Mn}$ 12.946 ~ 59.611 mg/L, SS 13.742 ~ 46.208 mg/L, T-N 2.037 ~ 5.213 mg/L, T-P 0.117 ~ 0.415 mg/L. And a differential between simulated EMCs and observed EMCs is too low so comparing result show high fit(BOD 4.27 %, $COD_{Mn}$ 4.87%, SS 2.31%, T-N 5.78%, T-P 14.45%). A results of compared with the prior studies, BOD and T-P are included range of prior studies, $COD_{Mn}$ and SS are lower than range of prior studies, T-N is higher than range of prior studies. Differential between simulated EMCs and prior studies EMCs was showing for survey seasonal and changing land-use, so from now on, EMCs of using the internal representatives value will be calculated by more monitoring toward various precipitation events.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.315-343
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• 2018

In the event of an air accident, the media and members of the general public pay attention to the victim of the accident and are deeply concerned about their actions and rewards. However, through the accident of Air China(CCA) Flight 129, which occurred in 2002, we were able to confirm that it is a real problem that the victims of the air accident as well as the victims suffer much suffering and serious aftermath. Nevertheless, Korea's system for assistance the families of victims of air accident is very poor. On the other hand, when Trans-World Airlines(TWA) Flight 800 exploded and crashed over the Atlantic Ocean in 1996, the United States enacted a law to assistance the families of the victims of the accident. According to this law, systematic assistance and management of not only the victims of the accident but also their families, minimize the additional damage of victims and victims' families and help them to get rid of the accident after the accident. In particular, the measures taken by the US authorities in response to an accident in which an Asiana Airlines flight(AAR) 214 crashed during a landing at San Francisco International Airport in 2013, made a lot of suggestions for us to assistance the victims and their families in an air accident. The purpose of this paper is to suggest the necessity of improving the system for victims and victim's family assistance in air accident. In this paper, we analyze the domestic and foreign legal systems and related cases in past accidents, identify the deficiencies of the Korean system, and derive the necessity to improve the related system. It is also important to make sure that victims' families are relieved from early psychological and economic shocks and that the results of accident investigations are reliable. Relevant ministries, airlines, and related agencies should recognize that prompt and systematic assistance and cooperation is needed to ensure that victims and families are relieved of the impact and confidence in the investigation, as is the case in the United States. In addition, efforts should be made to supplement the related laws for the assistance of aircraft victims and victims' families, to establish manuals for implementation, to plan and to implement them promptly in the event of an accident. To achieve this, it is necessary to establish regulations for the legal institutionalization of the roles and responsibilities of national and state agencies on victims of aviation accidents and family assistance. And the victim and family assistance plan that the airline has to submit to it, as specified in the current law, need to specify that item. In addition, new and supplemented contents should be integrated into a single clause or proposed as a separate special law for the purpose of applying a clear law.

• Journal of Intelligence and Information Systems
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• v.26 no.4
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• pp.149-171
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• 2020

The period at university is to make decision about getting an actual job. As our society develops rapidly and highly, jobs are diversified, subdivided, and specialized, and students' job preparation period is also getting longer and longer. This study analyzed the log data of college students to see how the various activities that college students experience inside and outside of school might have influences on employment. For this experiment, students' various activities were systematically classified, recorded as an activity data and were divided into six core competencies (Job reinforcement competency, Leadership & teamwork competency, Globalization competency, Organizational commitment competency, Job exploration competency, and Autonomous implementation competency). The effect of the six competency levels on the employment status (employed group, unemployed group) was analyzed. As a result of the analysis, it was confirmed that the difference in level between the employed group and the unemployed group was significant for all of the six competencies, so it was possible to infer that the activities at the school are significant for employment. Next, in order to analyze the impact of the six competencies on the qualitative performance of employment, we had ANOVA analysis after dividing the each competency level into 2 groups (low and high group), and creating 6 groups by the range of first annual salary. Students with high levels of globalization capability, job search capability, and autonomous implementation capability were also found to belong to a higher annual salary group. The theoretical contributions of this study are as follows. First, it connects the competencies that can be extracted from the school experience with the competencies in the Human Resource Management field and adds job search competencies and autonomous implementation competencies which are required for university students to have their own successful career & life. Second, we have conducted this analysis with the competency data measured form actual activity and result data collected from the interview and research. Third, it analyzed not only quantitative performance (employment rate) but also qualitative performance (annual salary level). The practical use of this study is as follows. First, it can be a guide when establishing career development plans for college students. It is necessary to prepare for a job that can express one's strengths based on an analysis of the world of work and job, rather than having a no-strategy, unbalanced, or accumulating excessive specifications competition. Second, the person in charge of experience design for college students, at an organizations such as schools, businesses, local governments, and governments, can refer to the six competencies suggested in this study to for the user-useful experiences design that may motivate more participation. By doing so, one event may bring mutual benefits for both event designers and students. Third, in the era of digital transformation, the government's policy manager who envisions the balanced development of the country can make a policy in the direction of achieving the curiosity and energy of college students together with the balanced development of the country. A lot of manpower is required to start up novel platform services that have not existed before or to digitize existing analog products, services and corporate culture. The activities of current digital-generation-college-students are not only catalysts in all industries, but also for very benefit and necessary for college students by themselves for their own successful career development.

• Management & Information Systems Review
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• v.23
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• pp.41-74
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• 2007

In Korea, corporate merger activities were activated since 1980, and nowadays(particuarly since 1986) the changes in domestic and international economic circumstances have made corporate managers have strong interests in merger. Korea and America have different business environments and it is easily conceivable that there exists many differences in motives, methods, and effects of mergers between the two countries. According to recent studies on takeover bids in America, takeover bids have information effects, tax implications, and co-insurance effects, and the form of payment(cash versus securities), the relative size of target and bidder, the leverage effect, Tobin's q, number of bidders(single versus multiple bidder), the time period (before 1968, 1968-1980, 1981 and later), and the target firm reaction (hostile versus friendly) are important determinants of the magnitude of takeover gains and their distribution between targets and bidders at the announcement of takeover bids. This study examines the theory of takeover bids, the status quo and problems of merger in Korea, and then investigates how the announcement of merger are reflected in common stock returns of bidding firms, finally explores empirically the factors influencing abnormal returns of bidding firms' stock price. The hypotheses of this study are as follows ; Shareholders of bidding firms benefit from mergers. And common stock returns of bidding firms at the announcement of takeover bids, shows significant differences according to the condition of the ratio of target size relative to bidding firm, whether the target being a member of the conglomerate to which bidding firm belongs, whether the target being a listed company, the time period(before 1986, 1986, and later), the number of bidding firm's stock in exchange for a stock of the target, whether the merger being a horizontal and vertical merger or a conglomerate merger, and the ratios of debt to equity capital of target and bidding firm. The data analyzed in this study were drawn from public announcements of proposals to acquire a target firm by means of merger. The sample contains all bidding firms which were listed in the stock market and also engaged in successful mergers in the period 1980 through 1992 for which there are daily stock returns. A merger bid was considered successful if it resulted in a completed merger and the target firm disappeared as a separate entity. The final sample contains 113 acquiring firms. The research hypotheses examined in this study are tested by applying an event-type methodology similar to that described in Dodd and Warner. The ordinary-least-squares coefficients of the market-model regression were estimated over the period t=-135 to t=-16 relative to the date of the proposal's initial announcement, t=0. Daily abnormal common stock returns were calculated for each firm i over the interval t=-15 to t=+15. A daily average abnormal return(AR) for each day t was computed. Average cumulative abnormal returns($CART_{T_1,T_2}$) were also derived by summing the $AR_t's$ over various intervals. The expected values of $AR_t$ and $CART_{T_1,T_2}$ are zero in the absence of abnormal performance. The test statistics of $AR_t$ and $CAR_{T_1,T_2}$ are based on the average standardized abnormal return($ASAR_t$) and the average standardized cumulative abnormal return ($ASCAR_{T_1,T_2}$), respectively. Assuming that the individual abnormal returns are normal and independent across t and across securities, the statistics $Z_t$ and $Z_{T_1,T_2}$ which follow a unit-normal distribution(Dodd and Warner), are used to test the hypotheses that the average standardized abnormal returns and the average cumulative standardized abnormal returns equal zero.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.119-125
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• 2024

The purpose of this study is to examine the radioprotection effect of mixtures of selenium and arginine for development of radioprotection agents that can minimize radiation damage to police special operation unit in the event of radioactive terrorism. In this study 72 male rats were classified into 4 groups: normal group(NC Group), selenium and arginine mixtures administration group(SeAr Group), radiation exposure group(IR Group), and selenium and arginine mixture administration group followed by radiation exposure(SeAr+IR Group). The 7Gy of X-ray was irradiated to whole body of SD rats. And selenium and arginine were dministered orally at 3mg/kg and 150mg/kg once a day for 14 days. And then hematological and histological analyzes were performed on days 1, 7, and 21 after radiation exposure. In hemotological analysis, significant radioprotection wes observed in lymphocytes(p<0.05) on day 1, platelet(p<0.01) on day 7, red blood cell(p<0.01) on day 21 of radiation exposure in SeAr+IR group compared to IR group. In histological analysis, it was observed that the border of small crypt cells in the small intestine was less collapsed and the length of small crypts was relatively recovered on day 7 and showed that the number of cells and cell wall thickness were better in the prostate on day 21 in SeAr+IR group compared to IR group. Therefore, it is judged that selenium and arginine mixtures have radioprotection effect on blood and tissues due to radiation exposure. it will be helpful for research on radioprotection agents to reduce radiation damage to police special operation unit.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.155-160
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• 2008

The urban areas have various landuses such as residential, commercial, industrial and official purposes that are highly concerned with human activities. The other landuses are relating to vehicle activities, which are roads, parking lots, bridges, parks etc. The mainly using landuses by human activities are possessing three different areas that are buildings, parking lots/roads and landscapes. Of these areas, the buildings and landscapes can be classified as non-pollution areas. However, the parking lots or roads are classifying as the main pollution areas because of vehicle activities. Therefore, the landuses arising the nonpoint pollution during a storm in urban areas are roads and parking lots. The vehicles are emitting lots of nonpoint pollutants such as metals and particulate matters and it is impacting on water qualities and aqua-ecosystems nearby the city areas. Therefore, this research was conducted for characterizing the pollutant types and determining the EMCs (Event Mean Concentrations) and unit pollutant loads during a storm. The monitoring was performed on 9 locations such as highways, service area, tollgates, parking lot and bridges. All of the landuses selected for monitoring are concerned with transportation. The results can be effectively used to predict the pollutant loading before urban planning and to select the BMPs (Best Management Practices) for reducing the pollution.