• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.16-22
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• 2020

The Korea Institute of Ocean Science & Technology is developing a free-fall cone penetration test system (FFCPT) that can acquire the characteristics of the seabed surface soil. To obtain the data through the FFCPT, a method of storing the signals for the entire time or a method of storing the signal for user-defined time can be considered. For efficient data storage and management, it is advantageous that data be stored by user definition. Therefore, this study analyzed the basic behavior using the signal acquired through a sensor mounted in the FFCPT and developed a trigger method to recognize the start and end of data storage using a depth sensor. The start and endpoints of the fall were determined using the moving average difference of 3 and 0.03 seconds of the depth signal. A real sea-trial test was performed using the FFCPT, and the developed trigger was operated normally.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.188-193
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• 2019

Transarterial chemoembolization (TACE) is a commonly used and rapidly evolving non-invasive treatment for hepatocellular carcinoma (HCC). It is important that understanding individual anatomical variants and planning for tumor-feeding artery access to acquire adequate treatment effectiveness. In this study, we will report acquired arteriovenous malformation which interferes with TACE for HCC. A 72-year-old man with persistent abdominal pain for 2 days visited our hospital. The patient was chronic hepatitis B carrier and had a history of HCC treated with conventional TACE 10 years ago. Hypervascular nodular HCC in the liver segment 8 and aberrant right hepatic artery from the superior mesenteric artery were detected on computed tomography (CT). When first TACE was performed, the tumor-feeding artery originating from the left hepatic artery was found and embolized. There was no tumor-feeding artery from the right hepatic artery but arteriovenous malformation was found. After a month, follow up CT showed necrotic lesion and residual HCC and we performed secondary TACE. On secondary TACE, we selected the right hepatic artery and passed through arteriovenous malformation. Superselective-angiogram showed remnant tumoral staining and remnant tumor was embolized using drug-eluting bead and Adriamycin. Final angiogram showed no remnant tumoral staining and the patient was discharged without complication. We found the rare case of arteriovenous malformation adjacent to HCC, and we performed superselective TACE beyond arteriovenous malformation to treat HCC.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.279-286
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• 2021

The purpose of this study is to compare the predictive power of the Bagging and Boosting algorithm of ensemble method based on the motion information that occurs in woman handball matches and to analyze the availability of motion information. To this end, this study analyzed the predictive power of the result of 15 practice matches based on inertial motion by analyzing the predictive power of Random Forest and Adaboost algorithms. The results of the study are as follows. First, the prediction rate of the Random Forest algorithm was 66.9 ± 0.1%, and the prediction rate of the Adaboost algorithm was 65.6 ± 1.6%. Second, Random Forest predicted all of the winning results, but none of the losing results. On the other hand, the Adaboost algorithm shows 91.4% prediction of winning and 10.4% prediction of losing. Third, in the verification of the suitability of the algorithm, the Random Forest had no overfitting error, but Adaboost showed an overfitting error. Based on the results of this study, the availability of motion information is high when predicting sports events, and it was confirmed that the Random Forest algorithm was superior to the Adaboost algorithm.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.9-17
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• 2022

To take into account of the increasing speed of next generation high-speed trains, a new design code for the traffic safety of railway bridges is required. To solve dynamic responses of the bridge, this research offers a numerical analyses of PSC (Pre-stressed Concrete) box girder bridge, which is most representative of all the bridges on Gyungbu high-speed train line. This model takes into account of the inertial mass forces by the 38-degree-of-freedom and interaction forces as well as track irregularities. Our numerical analyses analyze the maximum vertical deflection and DAF (Dynamic Amplification Factor) between simple span and two-span continuous bridges to show the dynamic stability of the bridge. The third-order polynomial regression equations we use predict the maximum vertical deflections depending on varying running speeds of the train. We also compare the vertical deflections at several cross-sectional positions to check the influence of running speeds and the maximum irregularity at a longitudinal level. Moreover, our model analyzes the influence lines of vertical deflection accelerations of the bridge to evaluate traffic safety.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.9
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• pp.717-722
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• 2001

This paper presents a methodology on the backward path tracking control of a trailer type robot which consists of two parts: a tractor and a trailer. It is difficult to control the motion of a trailer vehicle since its dynamics is non-holonomic. Therefore, in this paper, the modeling and parameter estimation of the system using a real-coded genetic algorithm(RCGA) is proposed and a backward path tracking control algorithm is then obtained based on the linearized model. Experimental results verify the effectiveness of the proposed method.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.42-55
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• 2011

The basic approach of this study was to take the theory of cultural fluctuations to investigate the early modern and modern patterns of the use of ox carts and@ the social and economic appropriateness and cultural significance of ox carts. The study chose a village that was the only place that used ox carts in Bugye-myeon. The findings will help to understand how traditional cultural elements would continue or change according to the natural, geographical, economical, and cultural characteristics of a village. Located in Gaho-2-ri, Bugye-myeon, Gunwi-gun, Gyeongbuk Province, Dongrim Village started to use ox carts during the Japanese rule and replaced the traditional version with an improved one in 1972 when a reservoir was built. Until the 1970s, they used ox carts to carry agricultural products and luggage and to visit the markets in distant Bugye-myeon or Gunwi-eup. In the early 1980s when a cultivator was first introduced into the village, ox carts gradually disappeared in the village and eventually remained as a mere means of transportation. As the younger generations were active in introducing modern means of transportation, a cultivator became the main means of transportation in the village in the 1980s and a truck since the latter half of the 1990s. Despite those changes, however, the elderly in their seventies or older continued to use ox carts. With aged labor and inability to use modern means of transportation, they grew cows and oxen to cultivate the inclined fields and gain easy access to fields distributed in distant locations and continued to ox carts through reform. In Dongrim Village, the heritage of using reformed ox carts is the practice of appropriate technology by the old farmers and a cultural representation of an aged agricultural society. That is, the elderly recognized the appropriateness and practicality of traditional culture and renewed a traditional means of transportation called an ox cart. The phenomenon of the old men and women frequently using ox carts in an agricultural village in the mountain with geographical limitations has settled down as a cultural representation of the elderly in Dongrim Village. The continuing usage of ox carts in Dongrim Village is attributed to the fact that ox carts well suit the natural, geographical, and economic aspects of the village and the cultural inertia of the elderly with the aging of the farmers. Thus it is once again shown that human beings transmit and alter culture according to their overall situations and conditions.