• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.5
• /
• pp.90-98
• /
• 2007

The objective of this investigation was to reveal the cause of the faulted cable(LV URD(low voltage underground) cable). For the analysis, various types or equipments such as external pattern, thermal pattern, surface structure, thermal analysis, and property distribution were deployed. The international standards and the specification provided by the manufacturer of faulted cable were examined whether it fit the standards. The summary is as follows. (1) Discovered as a factor lowering insulation performance of the faulted cable: minimum thickness of the insulation layer specified by IEC 60502-1 and IEC 60811-1-1 was not fit. (2) Infrared absorption peaks measured by FT-IR spectrometer revealed that the measurements made for the same material did not conform and it is an important basis for proving heterogeneous composition of the insulation material. (3) It was found that PVC bedding was thermally fragile and therefore long term exposure at the site could cause similar fault pattern.

• Tunnel and Underground Space
• /
• v.16 no.6 s.65
• /
• pp.506-525
• /
• 2006

For the design of large scale rock slope which has complex formations and geological structures, generally, insufficiency of geotechnical investigations and laboratory tests are the main factors of slope failures doling construction. In such case, remedial measures to stabilize slope should be selected and applied through reliable investigations and analysis considering the geotechnical characteristics. The rock slope of this study, one of the largest cut slopes in Korea with a length of 520.0 m and maximum height of 122.0 m consists of metasedimentary rocks. And a case study on the causes of large-scale rock slope failure was carried out by analysis of landslides history and site investigations during construction. When the slope with the original design slope of 0.7: 1.0 (H:V) was partially constructed, the slope failure was occurred due to the factors such as poor conditions of rocks (weathered zone, coaly shale and fault shear zone), various discontinuities (joints, foliations and faults), severe rain storm and so on. The types of failures were rockfall, circular failure, wedge failure and the combination of these types. So, the design of slope was changed three times to ensure long-term slope stability. This paper is intended to be a useful reference for analyzing and estimating the stability of rock slopes whose site conditions are similar to those of this study site such as geological structures and geotechnical properties.

• Journal of Korean Public Health Nursing
• /
• v.12 no.1
• /
• pp.103-115
• /
• 1998

As the studies that smoking can be a major cause to various diseases have been made, many following researches on the outcome of stop-smoking education were in progress. Even though researches based on the knowledge about smoking and status about the teenagers were prevalent, the research based on the outcomes in long time basis were not in progress. Therefore, I tracked the people who went through 5-Day Stop-Smoking School that has taught through complexed structure of behavioral, intellectual, and psychological education. I made researches on the average of success and the hardest point during their efforts to stop just to show the necessity of going through re-education. The objectives of this study were the ones who have completed the education on the years 1990, 1991. 47 were selected from 364 people that completed the training, and who were able to be contacted on the phone line. This study was conducted from 27 Oct. to 7 Nov. 1997 through verbal interviews based on the questionnaire. The questionnaire used here was made by myself, assisted by my professor. Analysis was made through unstructured open questions. The data was analyzed using SPSS program. The major results were as follows ; 1) General characteristics of the objectives are $97.0\%$ were male, $17\%$ ages below 40s, $34\%$ in the age group of 40s, and $48.9\%$ over 50s. Religiously christian 340/0, buddhist $19.1\%$, no religion or any other reason $46.8\%$. Status married $93.6\%$, unmarried $6.4\%$. There is someone smoking in the family $36.2\%$, no one smokes $63.8\%$. Reputation salary men $55.3\%$, personal business $27.7\%$. 2) The average of success is $42.6\%(20/47)$, the failure is $57.4\%$. 3) The results from the study 'When was the hardest point in the process of stop smoking' : For the successors the first week $33.3\%$, after the first week $66.7\%$. For the failures the first week $55\%$, after first week $45\%$(Statistics not precisely done), the most effective element that helped through the hardest point was the family $40\%$, personal determination $30\%$. 4) The necessity of re-education : Successors needed $55\%$, not needed $45\%$. Failures needed $48.1\%$, not needed $51.9\%$(Statistics not precisely done). The perfect time for reeducation : Successors in 6 months $50\%$, irregular time basis $50\%$. Failures in six months $36.4\%$, after six months $27.3\%$, irregular time basis $36.4\%$(Statistics not precisely done). Synthesizing the result of the study can't generalize the long-term effect of the stop-smoking due to the number of the objectives,. but recognize the fact that 47.6 have experienced success, and also the self-determination and the support from the family are desirable. Seeing the fact that both are great motivation to stop smoking. Since the first week is necessary. The necessity of re-education is rather high, so this education should be planned to be done repeatedly in a long term along with close observation, instead of short education.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.7
• /
• pp.67-79
• /
• 2009

Although readjustment of monitoring system for existing fill dam maintenance is needed by the sustainable increasing of the abandonment rate of monitoring devices by malfunction through the life-cycle of dam, monitoring plans for long-term dam safety has relied on the experience and the opinion of minor expert group without systematic and quantitative analysis on the failure modes and the priority order of monitoring devices on maintenance. In this study the priority order of monitoring devices of existing 5 fill dams was evaluated quantitatively based on the preceding study (Andersen et al, 1999) and the result recommended the establishment of real-time monitoring system for seepage, pore pressure and crest settlement as the readjustment plan for existing fill dam monitoring system. This readjustment plan matches well with the recommendation of PWRI (1984), JCOLD (1986) and the results from Bagherzadeh-Khakkahali and Mirghasemi (2005).

• Korean Circulation Journal
• /
• v.54 no.2
• /
• pp.78-90
• /
• 2024

Background and Objective: We aimed to investigate long-term clinical and echocardiographic outcomes, including tricuspid valve durability, annular growth, and left ventricular reverse remodeling, after modified cone reconstruction in patients with Ebstein's anomaly. Methods: This was a retrospective analysis of all pediatric patients who underwent modified cone reconstruction for Ebstein's anomaly at a single tertiary center between January 2005 and June 2021. Results: A total of 14 pediatric patients underwent modified cone reconstruction for Ebstein's anomaly; the median age was 5.8 years (range, 0.01-16.6). There were three patients (21.4%) with Carpentier type B, ten patients with Carpentier type C (71.4%), and one patient with Carpentier type D (7.1%). There was no early or late mortality, arrhythmia, or readmission for heart failure at a 10-year follow-up. There were no cases of more than mild tricuspid stenosis or more than moderate tricuspid regurgitation during the study period, except for one patient with severe tricuspid regurgitation who underwent reoperation. The z value for tricuspid valve annular size significantly decreased immediately after the operation (2.46 vs. -1.15, p<0.001). However, from 1 year to 7 years after surgery, the z values were maintained between -1 and +1. Left ventricular end-systolic volume, end-diastolic volume, and stroke volume increased after surgery and remained elevated until seven years postoperatively. Conclusions: Ebstein's anomaly in children can be repaired by modified cone reconstruction with low mortality and morbidity, good tricuspid valve durability, and annular growth relative to somatic growth.

• International Journal of Computer Science & Network Security
• /
• v.24 no.10
• /
• pp.1-16
• /
• 2024

Due to its complexity and high diagnosis and treatment costs, heart attack (HA) is the top cause of death globally. Heart failure's widespread effect and high morbidity and death rates make accurate and fast prognosis and diagnosis crucial. Due to the complexity of medical data, early and accurate prediction of HA is difficult. Healthcare providers must evaluate data quickly and accurately to intervene. This novel hybrid approach predicts HA using Long Short-Term Memory (LSTM) networks, Deep belief networks (DBNs) with attention mechanism, and robust data mining to fill this essential gap. HA is predicted using Kaggle, PhysioNet, and UCI datasets. Wearable sensor data, ECG signals, and demographic and clinical data provide a solid analytical base. To maintain consistency, ECG signals are normalized and segmented after thorough cleaning to remove missing values and noise. Feature extraction employs complex approaches like Principal Component Analysis (PCA) and Autoencoders to pick time-domain (MNN, SDNN, RMSSD, PNN50) and frequency-domain (PSD at VLF, LF, HF bands) characteristics. The hybrid model architecture uses LSTM networks for sequence learning and DBNs for feature representation and selection to create a robust and comprehensive prediction model. Accuracy, precision, recall, F1-score, and ROC-AUC are measured after cross-entropy loss and SGD optimization. The LSTM-DBN model outperforms predictive methods in accuracy, sensitivity, and specificity. The findings show that several data sources and powerful algorithms can improve heart attack predictions. The proposed architecture performed well on many datasets, with an accuracy rate of 96.00%, sensitivity of 98%, AUC of 0.98, and F1-score of 0.97. High performance proves this system's dependability. Moreover, the proposed approach is outperformed compared to state-of-the-art systems.

• International Journal of Concrete Structures and Materials
• /
• v.2 no.2
• /
• pp.137-143
• /
• 2008

In recent years, much research work has been performed on durability design and long-term performance of concrete structures in marine environments. In particular, the development of new procedures for probability-based durability design has been shown to provide a more realistic basis for the analysis. This approach has been successfully applied to several new concrete structures, where requirements for a more controlled durability and service life have been specified. For reinforced concrete structures in a marine environment, it is commonly assumed that the dominant degradation mechanism is the corrosion of the reinforcement due to the presence of chlorides. The design approach is based on the verification of durability limit states, examples of which are: depassivation of reinforcement, cracking and spalling due to corrosion, and collapse due to cross section loss of reinforcement. With this design approach the probability of failure can be determined as a function of time. In the present paper, a probability-based durability performance analysis is used in order to demonstrate the importance of the durability design approach of concrete structures in marine environments. In addition, the sensitivity of the various durability parameters affecting and controlling the durability of concrete structures in a marine environment is studied. Results show that the potential of this approach to assist durability design decisions making process is great. Based the crucial information generated, it is possible to prolong the service life of structures while simultaneously optimizing the final design solution.

• International journal of advanced smart convergence
• /
• v.8 no.1
• /
• pp.166-175
• /
• 2019

Grit, a concept conceived in 2007 by Duckworth and others in the United States, is based on positive psychology that focuses on growth and development through individual strengths. Recently, "Grit", which means patience and enthusiasm for long-term goals, has emerged as a key factor of personality strength. In Korea, Joo-hwan Kim (2013) was the first to conceptualize and study the subject of Grit. However, there have been no overview studies that systematically summarize the overall trends and flow in the research of Grit so far. There have been 147 research papers on Grit published so far in Korea. The purpose of this study was to conduct trend analysis on the subject of Grit by analyzing forty-three (43) master's and doctoral dissertations, thus presenting the direction of future research on Grit through careful analysis. In the studies conducted, it was found that Grit is a very significant variable linked to self-efficacy. It is also a subjective belief that can help an individual achieve his/her educational goals, and go through failure resynchronization. In addition, Grit is very significant as a practical core indicator of how fusion talent is fostered for the fourth industrial revolution. Therefore, there is a need for more in-depth research from the viewpoints of workplace learning, experiential learning, or informal learning, as well as research into Grit characteristics.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.17 no.3
• /
• pp.178-187
• /
• 2005

A reliability analysis model f3r studying the influence of joint distribution of wave heights and periods on wave un-up is presented in this paper. From the definition of failure mode related to wave run-up, a reliability function may be formulated which can be considered uncertainties of water level. In particular, the reliability analysis model can be directly taken into account statistical properties and distributions of wave periods by considering wave period in the reliability function to be a random variable. Also, variations of wave height distribution conditioned to mean wave periods can be taken into account correctly. By comparison of results of additional reliability analysis using extreme distributions with those resulted from joint distribution of wave height and periods, it is found that probabilities of failure evaluated by the latter is larger than those by the former. Although the freeboard of sloped-breakwater structures can be determined by extreme distribution based on the long-term measurements, it may be necessary to investigate additionally into wave run-up by using the present reliability analysis model formulated to consider joint distribution of a single storm event. In addition, it may be found that the effect of spectral bandwidth parameter on reliability index may be little, but the effect of wave height distribution conditioned to mean wave periods is straightforward. Therefore, it may be confirmed that effects of wave periods on the probability of failure of wave run-up may be taken into account through the conditional distribution of wave heights. Finally, the probabilities of failure with respect to freeboard of sloped-breakwater structures can be estimated by which the rational determination of crest level of sloped-breakwater structures may be possible.

• Journal of Korean Society of Forest Science
• /
• v.94 no.6
• /
• pp.377-386
• /
• 2005

This study was carried out to analyse the landslide characteristics by ground investigation, borehole image processing system, field seismic test, laboratory test and ground stability analysis at the landsliding area occurred in Maeri, Sangdong-myeon, Gimhaesi, Gyeongsangnam-do. Region I needs to install data logger system to monitor a land displacement during the heavy rainfall events because the region can be liable to occur the land slide by land creeping. It is needed to restore rapidly, if the land displacement occurs in Region I. Region II needs to monitor and repair because of the possibility of slope failure by long-term soil loss. Region III needs constructions to remove ground runoff and ground water to be infiltrated from talus. Region IV where is a stable region, needs to be protected from land cutting or other man-made damage.