• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.44-52
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• 2007

Contaminated sediments more than 30 million/$m^3$ is generated from dredging work for harbours and coastal maintenance in Korea. Approximately 300 million/$m^3$ of sediments is dredged to deepen harbours and shipping lanes in US and of which $3{\sim}12million/m^3$ is highly contaminated. Although much is known about technologies for the remediation of heavy metal contaminated soil, much less is known about the treatment of contaminated sediment. In general, negatively charged fine particles will migrate towards positively charged system of electrodes under the influence of electrophoresis. However, the electrically induced migration of colloidal particles contaminated with heavy metals may be hindered by the positively charged heavy metal contaminants adsorbed onto the soil surfaces depending on the contamination level. This paper demonstrates settling behaviour of clayey soil by comparison with electrophoretic particle movement under the effects of heavy metal contamination, applied electric field strength, and its polarity changed by the electrode configuration.

• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.17-22
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• 2008

The feasibility of acid-enhanced electrokinetic remediation on zinc and nickel-contaminated soil was investigated in the laboratory. Simple extraction efficiency using 1M HCl was 24% for Zn and 9% for Ni, as a result, the acid washing is not effective to remove Zn and Ni from the soil. The effiencey of normal electrokinetic treatment during 28 days was less than simple soil washing. Catholyte circulation with a strong acid enhanced dramatically the removal of Zn and Ni and pretreatment of soil with acid increased more the removal. Based on the result, acid-enhanced electrokinetic remediation is effective to remove Zn and Ni from the contaminated soil.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.9-16
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• 2003

A new method has been proposed and developed that solves the problem of decreasing electroosmotic flow rate by excess $H^{+}$ and precipitation of heavy metal by $OH^{-}$. An electrolytic solution was circulated between the anode and cathode compartments that enabled the pH at the anode and cathode to be controlled. The change of the soil pH by circulation systems affects the operation time, by lowering the rate of increase of the electric potential gradient, and the removal efficiency of heavy metals, by affecting the soil pH. Since there was no effluent from the cathode compartment in circulation system, there was no need to treat the wastewater after the experiment, which resulted in the reduction of influent electrolyte volume.

• (The)Study of the Eastern Classic
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• no.73
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• pp.153-184
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• 2018

The aim of this thesis was to examine the circumstances that led up to successful coin use across the entire nation in 1678 (the $4^{th}$ year of King Sukjong's reign), during the Joseon Dynasty. To this end, this thesis analysed the Sa-Mouk(事目, Provisions) that contained the institutional protocol for coin circulation, implemented by King Hyojong and the statesman Kim Youk(金堉) who had practical experience in these matters over the ten years of King Hyojong's reign(1649-1659). To regulate the problematic wide circulation of coarse cotton cloth as currency in the market of 1650 (the $1^{st}$ year of King Hyojong's reign), prohibition measures were implemented. Besides the superficial justification given for these measures(i.e., that the market price was disturbed by the use of coarse cotton cloth), there was another purpose to prohibiting the circulation of cotton cloth as money, following the standard ruled by the government: the state aimed to ensure momentum for the upcoming coin circulation policy, by strengthening its control of the current economy. In 1651 (the $2^{nd}$ year of King Hyojong's reign), the government fully cracked down on the use of coarse cotton cloth as currency, and simultaneously implemented its coin circulation policy in the Pyeongan(平安) region. The pretext for this policy was to raise finances to support people who were starving as a result of poor harvests and famine. People who received coins from government officials could purchase food in the market, and the coin circulation policy was judged to be successful. Subsequently, to extend coin circulation further throughout the region, the Sa-Mouk for Seoul was established. The Sa-Mouk included stipulations regarding the use of coin in transactions and for government expenditure; it aimed thereby to enhance the national policy's market credit. The hasty implementation of the policy for the expansion of coin circulation caused some problems that required its modification. In 1652 (the $3^{rd}$ year of King Hyojong's reign), coin circulation was increased to encompass the Gyeonggi(京畿) region, and some of the tax that had been paid in rice was now paid in coin. However, coins were in short supply, since there was insufficient copper, the main material used in coin production, and the policy faced a significant limitation. Therefore, in 1655(the $6^{th}$ year of King Hyojong's reign), a new Sa-Mouk for coin circulation was established. This Sa-Mouk included specifications regarding the determination of coin values based on rice and silver, and mandated the wide spread installation of stores for exchanging spot goods for coins throughout the region in which coins were circulating. This policy's objective was to secure stability for the national economy by further regulating coin circulation. The sustained implementation of the coin circulation policy for ten years by King Hyojong and the statesman Kim Youk offered the government an opportunity to accumulate experience in coin circulation in the market, and also to learn from institutional trial and error. This may have been one of the contributing factors to the nation-wide coin circulation that was established in 1678. The objective of the policy implemented during King Hyojong's reign was not to meet the market's requirements, but rather to ensure the preservation of the national economy, and this misjudgement constituted the policy's key limitation. At this time, the government urgently needed to secure finances to cope with the war against China's Qing Dynasty.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.99-100
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• 2015

거래 시 발생하는 잔돈들로 인해 이용자들은 소지의 불편함이 있고 서랍속에서 잠자고 있는 동전들로 인해 연간 수억 원의 동전 발행 비용이 발생하고 있다. 본 시스템은 스마트 기기들을 이용한 사용자들을 대상으로 잔돈을 적립하여 기부하기, 선물하기, 구매하기 등의 시스템을 설계하고 이를 테스트하였다. 본 시스템은 기본적인 잔돈 적립 및 소비 기능 외에 가맹점이 확보되지 않은 상태에서 사용자 앱을 테스트할 수 있도록 설계한 부분과 SNS와 연계되어 커뮤니티를 활용할 수 있다는 것이 특이점이다. 본 시스템을 통해서 이용자들의 편의성과 만족, 동전 발행이라는 사회적 비용 절감, 기부문화의 확산 등을 기대하고 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.11-17
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• 2004

In this paper, A miniature broad-band dime antenna is designed. This antenna consists of two stacked circular patches that create two cylindrical slots resonating at two slightly different frequencies, fed by a strategically positioned coaxial prove. To increase the bandwidth of microstrip patch antenna, a configuration of stacked type is used. Furthermore, to reduce the size of microstrip patch antenna and obtain a double resonant behavior, two shorting-walls are used. Experimental results show that the antenna bandwidth is about 26% centered at 5.8㎓ and are close agreement with the calculation results by HFSS 7.0 software.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1007-1009
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• 2009

In this paper, to introduce synthetic concept of electronic cash that it solved disability elements of e-money issued by existing operators. In addition, a wireless network offers enhanced features due to RFID-technology. Moreover, The mobile phones, easy deployment, equipped with electronic money functions and should be give a convenience of mutual gift. Finally, To introduce concept of coin purse that it gets out of the inconvenience possession and loss of the concerns, casting cost about coin.

• Annual Conference of KIPS
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• 2020.05a
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• pp.320-322
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• 2020

기계학습은 인공지능의 한 클래스로 최근 이미지 및 음성인식, 지능적 웹 검색, 자율 주행 자동차 등의 영역에서 성공적 발전을 바탕으로 우리의 일상에 폭넓게 이용되고 있다. 본 논문에서는 Keras 오픈소스 라이브러리를 이용해 딥러닝을 이용한 기계학습 기반의 동전 인식 소프트웨어를 구현하였고, 이를 이용해 동전 자동분류 스마트 저금통을 설계하였다. 동작 검증을 위하여 스마트 저금통의 모든 발생 이벤트는 Parse-server와 mongoDB를 이용하여 시각화 및 어플리케이션 및 웹사이트를 연결하였다.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.25-32
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• 2000

The electrokinetic apparatus for remediation of the soil contaminated with $Sr^{2+}$ was designed. After kaolin clay compulsorily contaminated by $Sr^{2+}$ solution, the remediation characteristics by electrokinetic method were analyzed. Meanwhile. the numerical code for analysis of electrokinetic migration was developed for modelling of the soil remediation. And the input parameters needed for modelling were measured by laboratory experiment or taken from literature. Experimental results are as follows: After 3 day remidiation under 40 voltage, the front part of experimental cell was almost decontaminated, but the behind part didnt almost be decontaminated. Consequently. the total remediation ratio of $Sr^{2+}$ from cell soil was about 42.6%. Also, the total $Sr^{2+}$remediation ratio from cell soil was about 84.8% after 6 days. The values calculated by the developed code almost agreed with experimental values When voltages of electrode were increased by 10, 30, 40V, the total $Sr^{2+}$ remediation ratlos were about 21.9%. 43.3%, 84.8%, respectively, after 6 days.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.1-12
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• 2003

The purpose of this study was to investigate the effect of high voltage pulsed current stimulation (HVPCS) on the healing rate of a dermal wound in a rat. We also determined the mechanism of promoting healing by HVPCS. Twenty male Sprague-Dawley rats were randomly divided into two group; HVPCS group (n=10) and control group (n=10). The HVPCS rats received electrical stimulation with a current intensity of 50 V at 100 pps for a duration of 30 minutes, while the control group was given the same treatment without electricity for a week. The biopsy specimens were fixed in formalin, embedded in paraffin and stained with Masson's trichrome, hematoxylin and eosin (H&E). The fibroblasts and collagen density were counted using a light microscope and computerized image analysis system and calculated as the density and the percent. A Student t-test showed a significantly higher wound healing rate of the HVPCS group than control (t=-4.161, p<0.001). The fibroblasts in the HVPCS group were higher than in the control group (t=-4.921, p<0.001). The density of collagen in the HVPCS group was also higher than in the control group (t=-4.367, p<0.001). These results indicate that the HVPCS accelerated the rate of healing in dermal wound, and increased fibroblasts and collagen density in the regenerative dermis. These findings suggest that the HVPCS may activate fibroblasts by alteration of the electrical environment, and it may increase collagen synthesis in the regenerative dermal wound.