• Korean Security Journal
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• no.22
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• pp.91-111
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• 2010

Around the middle of the ninth century the strict bone-rank system of Silla frustrated many people who had political ambition but lacked nobility. They had to seek other ways, including maritime trade. Such an undertaking reflected and also increased their economic and military power. Trade prospered with T'ang China and with Japan as well. The threat of piracy to Silla's thriving maritime trade caused to create a succession of garrisons at important coastal points. Chonghae Jin (Chonghae garrison) was regarded as the most important of these. It was established in 828 by Chang Pogo. Chonghae Jin was on Wando, an island just east of the southwestern tip of Korea and a key place at this time in the trade between China, Korea, and Japan. From this vantage point Chang Pogo became a merchant-prince with extensive holdings and commercial interests in China and with trade contacts with Japan. Although piracy was rampant in East Asia at that time, either the Chinese or Silla government was not able to control it due to inner political strife and lack of policing resources. Infuriated by the piracy and the government's inability to control it, Chang Pogo came back to Silla to fight against the pirates and to protect maritime trade. He persuaded the king of Silla and was permitted to control the private armed forces to sweep away the pirates. In 829 he was appointed Commissioner of Chonghae-Jin with the mission of curbing piracy in that region. Chang's forces were created to protect people from pirates, but also developed into traders among Silla Korea, T'ang China, and Japan in the 9th century. This was geographically possible because the Chonghae Garrison was situated at the midpoint of Korea, China, and Japan, and also because Chang's naval forces actually dominated the East Asia Sea while patrolling sea-lanes. Based on these advantages, Chang Pogo made a great fortune, which might be collected from a charge for protecting people from pirates and the trades with China and Japan. Chang's forces could be termed the first private security company in the Korean history, at least in terms of historical documents. Based on historical documents, the numbers of private soldiers might be estimated to exceed tens of thousands at least, since Chang's forces alone were recorded to be more than ten thousand. Because local powers and aristocratic elites were said to have thousands of armed forces respectively, the extent of private forces was assumed to be vast, although they were available only to the privileged class. In short, the domination of Chang's forces was attributable to the decline of central government and its losing control over local powers. In addition it was not possible without advanced technologies in shipbuilding and navigation.

• Korean Security Journal
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• no.34
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• pp.7-32
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• 2013

The idea of this study was derived from awareness of local governments and police's limitation on attempts to 'creating safe park'. The purpose of this study is to examine current political measures of preventing various types of possible crimes in the park and the limitation of those policies. Furthermore, this study aims to suggest possible explanations to utilize Private Security Sector for the effective and continuous way of managing park safety by considering legal and practical solutions and its expectations. The methods of analysis used in this study are, first, literature review of current park safety management policies. Second, this article examined implications of strategies of those policies throughout the case study of the USA's park safety policy. Third, this study suggested plans of action and role of Private Security Sector to improve park safety. The results present several arguments for the park safety. First, legislation of mandatory crime preventing programme in the early stages of designing park is required. Introducing the 'park special judicial police system' to the major parks for a immediate response to the crime can be one of suggestions. Moreover, proactive police response systems, such as one of the Seoul Metropolitan Police's policies- 'returning safe parks to a citizen' are required. Second, the case study of the USA regarding park safety confirmed that major parks in the USA have rigorous and detailed park regulations. It also showed that those parks take not only preventing measures, but also follow-up measures against crimes. Third, the results suggest creating human resources by contracting out Park Managers and Private Security Sector that have specialized experiences and techniques to prevent crimes and public disorders. Overall in this study, increased citizen's satisfaction level, control of continuous and systematic crimes, the spread of joint-production of public safety, and increased fields of the Private Security Sector are expected from the findings.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.109-118
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• 1999

Recently, transport parameters of conservative solutes such as KCl in a porous medium have been successfully determined using time domain reflectometry (TDR) . This study was initiated to Investigate the applicability of TDR technique to monitoring the fate of a heavy metal ion in a sandy soil and the distribution of its concentration along travel distance with time. A column test was conducted in a laboratory that consists of monitoring both resident and flux concentrations of $ZnCl_2$in a sandy soil under a breakthrough condition. A tracer of $ZnCl_2$(10 g/L) was injected onto the top surface of the sample as pulse type as soon as a steady-state condition was achieved. Time-series measurements of resistance and electrical conductivity were performed at 10 cm and 20 cm of distances from the inlet boundary by horizontal-positioning of parallel TDR metallic rods and using an EC-meter for the effluent exiting the bottom boundary respectively. In addition. Zn ions of the effluent were analyzed by ICP-AES. Since the mode and position of concentration detected by TDR and effluent were different, comparison between ICP analysis and TDR-detected concentration was made by predicting flux concentration using CDE model accommodating a decay constant with the transport parameters obtained from the resident concentrations. The experimental results showed that the resident concentration resulted in earlier and higher peak than the flux concentration obtained by EC-meter, implying the homogeneity of the packed sandy soil. A close agreement was found between the predicted from the transport parameters obtained by TDR and the measured $ZnCl_2$concentration. This indicates that TDR technique can also be applied to monitoring heavy metal concentrations in the soil once that a decay constant is obtained for a given soil.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.867-879
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• 2016

Since the 1970s, the region of its own pedestrian center and environmental pollution caused by exhaust gases have been reduced gradually in a continuous increase of the vehicle, school route the central business district, around the school, the sidewalk where the vehicle do not pass, facilities of minimum for the safety of pedestrians and systematic management of an area where an unspecified number and alleys impassable is insufficient. Recently, in response to the "Law for convenience enhancing safety and walking" is enforced in Korea, research on Pedestrian only Street has been actively about the government, the standard for calculating the weights of evaluation associated with it. it is a actuality, however, there are insufficient, evaluation for business promotion is being conducted evaluation polite manner by using, for example, scale residence time and purpose of the passengers as there is no car that has been carried out on a voluntary basis through the municipality have. In this study, by suggesting a method for the selection of the street without a car, make a survey by placing a purpose in the selection method presentation of the street with no car to be construction future, was researching. F.G.I (Focus Group Interview) survey, professors, staff in urban, traffic field of experts in order to present the weights for the evaluation of the Pedestrian only Street by using the evaluation index by type of Pedestrian only Street, was interviewed about the evaluation index for the conducted for professionals engaged in the engineering company, and randomly selected 200 peoples, weighted evaluation of the street with Pedestrian only Street was proposed. By classifying the items purpose and goals of the evaluation type by this by applying the weight, and present the weight of the detailed indicators each corresponding to each item, and scored on the basis of the result, in this paper it can be so that one methodology for the selection standard for the construction as Pedestrian only Street, and the weight of the evaluation of the type that has been derived, the selection and evaluation methods and then added to these criteria to settle careful study of the reference should be performed further.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.83-107
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• 2009

The purpose in this study was to provide a basic resource for enhancing teachers' professional competence by examining how the Home Economics(HE) teachers had formed, developed, and introspected the pedagogical content knowledge in the HE classes of secondary schools. Data were collected through in-depth interviews with six HE teachers working at secondary schools. NVivo program, a kind of CAQDAS was used to analyze the data inductively. This study revealed that the HE teachers reflectively introspected the pedagogical content knowledge in Home Economics Education(H-PCK) as follows: First, as for knowledge of perspective on Home Economics Education(HEE), the research participants encouraged students to solve practical problems regarding the objective of HEE. They tried to foster the students' critical thinking ability related to the daily life. They made eager efforts to achieve the mission of HEE as a practical science. Second, as for knowledge of HE curriculum, the research participants mentioned that there was lack of systematic approach concerned with curriculum development. While reorganizing, they always paid attention to its relation to the students' daily lives, to the relationship between the curriculum contents and the social context. Third, as for knowledge of teaching strategies on practical problem-based instruction, the research participants developed the practical problem-based instruction skills. They mentioned students' difficulties in relating the practical problem-based instruction, too. Fourth, regarding knowledge of context, as teachers mostly prepared for progressed instruction alone without communicating with colleagues in the same school, they yearned for and also formed networks with other HE teachers in order to overcome their limitations.

• Journal of the Korean earth science society
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• v.33 no.3
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• pp.269-279
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• 2012

Satellite-retrieved data on Aerosol Optical Depth (AOD) and ${\AA}$ngstr$\ddot{o}$m exponent (AE) using a Moderate Resolution Imaging Spectrometer (MODIS) were used to analyze large-scale distributions of atmospheric aerosols in East Asia. AOD was relatively high in March ($0.44{\pm}0.25$) and low in September ($0.24{\pm}0.21$) in the East Asian region in 2009. Sandstorms originating from the deserts and dry areas in Northern China and Mongolia were transported on a massive scale during the springtime, thus contributing to the high AOD in East Asia. Although $PM_{10}$ with diameters ${\leq}10{\mu}m$ was the highest in February at Anmyon, Cheongwon and Ulleung, which is located leeward about half-way through the Korean Peninsula, AOD rose to a high in May. The growth of hygroscopic aerosols moving with increases in relative humidity prior to the Asian monsoon season contributed to a high AOD level in May. AE typically reaches its highest value ($1.30{\pm}0.37$) in August due to anthropogenic aerosols originating from industrial areas in Eastern China, while AOD stays low in summer due to the removal process caused by rainfall. The linear correlation coefficients of the MODIS AOD and ground-based mass concentrations of $PM_{10}$ at Anmyon, Cheongwon and Ulleung were 0.4-0.6. Four cases (six days) of mineral dustfall from sandstorms and six cases (twelve days) of anthropogenically polluted particles were observed in the central area of the Korean Peninsula in 2009. $PM_{10}$ mass concentrations increased at both Anmyon and Cheongwon in the cases of mineral dustfall and anthropogenically polluted particles. Cases of dustfall from sandstorms and anthropogenic polluted particles, with increasing $PM_{10}$ mass concentrations, exhibited higher AOD values in the Yellow Sea region.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.612-617
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• 2008

Tetrodotoxin (TTX) analogues were first determined from the liver extracts of puffer fish, Takifugu niphobles, by LC/MS with Hydrophilic Interaction Liquid Chromatography (HILIC). In total, 7 TTX analogues were detected within 20 minutes as follows; 5,6,11-trideoxyTTX (34.0%, 1,029.6 nmol/g), 6,11-dideoxyTTX (29.3%, 887.6 nmol/g), TTX (22.1%, 667.8 nmol/g), 4,9-anhydro-TTX (11.2%, 339.3 nmol/g), 11-deoxyTTX＋5-deoxyTTX (2.6%, 78.6 nmol/g), and 4-epiTTX (0.8%, 23.6 nmol/g). Mouse toxicity of diluted liver extracts showed the highest toxicity at pH 3 (8.7 MU/mL) and decreased, as increasing pH, to 1.4 MU/mL at pH 10. At acidic (pH 5) and neutral conditions (pH 7), mouse toxicity of liver extracts (79 MU/mL) decreased slowly, as increasing temperature from $80^{\circ}C$ to $115^{\circ}C$, and time until 1 hour; in contrast, at the akaline condition (pH 9), the toxicity decreased rapidly to the more than half within 10 minutes. Individual toxicity of the fillet of T. niphobles were between $43.2{\sim}106.7$ MU, and $64{\sim}78%$ of its toxicity was eluted to soup when boiled with 3 volumes of water during 10 minutes.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.2
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• pp.37-51
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• 2018

Recently, urban parks are required to actively participate with residents in order to strengthen social functions and maintain sustainable management. This study analyzed the formation process of volunteer resident groups (Chamsamo) in the neighborhood parks in which local residents can participate in an ongoing basis based on the solidarity of a daily living space. The important factors in the activation of resident activity are derived from 5 aspects including resources, local area, resident group capacity, resident group role, and public support. The results of the study are as follows. 1) Life-friendly resources: It was important to find life-friendly resources such as 'Chamsaem' in the park. The combined resources of continuous human activities provided various benefits to the residents. This has led to stronger attachment and community activities to continue to utilize attractive resources in the park. 2) Sharing Common Daily Spaces and Expansion: As the Chamsamo activities were centered around the neighborhood, the network of activists in the local community expanded. This led to continued resident interest and favorable participation as well as to the regional expansion of Chamsamo activities. 3) Park management as part of everyday life: Park management became a part of everyday life, and pleasant park management was facilitated by utilizing the talents of the residents, who carried out diverse activities and constantly streamlined their hard labor. 4) Chamsamo's Leadership Linking Residents and the Public Sector through Leading Park Management Activities: Chamsamo served as a middle leader in linking the public sector and its users. 5) Role and Support of the Public Sector: In order to be able to sustain the activities of residents, the government's willingness to support the resident-led activities of the park in planning and operating the public sector was required. In the public management system of the park, support for residents' activities such as financing, education, and consulting was necessary.

• Journal of the Korean earth science society
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• v.21 no.2
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• pp.103-115
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• 2000

The ability-grouping is the essence of the seventh educational curriculum, applied to school from year 2000, and its enriched-supplementary type will be carried out for science course. This study examines the effect of the enriched-supplementary ability-grouping within class to student's academic achievement and the attitude, related to science. Thus we developed teaching and learning methods with intellectual level about the subject of 'Water Circulation and Weather Change' in Middle-School Science 2. Then we tested 152 eighth graders who were divided into the experimental and control groups. The experimental one was taught through the ability-grouping for about six weeks, while the control through conventional lecture. The improvement of the experimental group in academic achievement was more effective than that of the control, and particularly to below-average students who ranked in lower thirty percent. The experimental one got more negative change in domain 'Science as a Subject, and in subdomain 'Anxiety in Science Lesson'. While outstanding students who ranked in upper thirty percent showed a significant positive change in subdomain 'Satisfaction in Teaching Method, the below-average were negatively changed in subdomain 'Anxiety in Science Lesson'. The current ability-grouping was suitable for the improvement of academic achievement, but not for the general attitude related to science. In order to enhance the ability-grouping effect in science education, we need to additionally consider student's interest and concern in grouping, and develop various teaching and learning methods together with proper textbook contents.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.504-519
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• 2020

Oceanic fronts, which are areas where sea water with different properties meet in the ocean, play an important role in controlling weather and climate change through air-sea interactions and marine dynamics such as heat and momentum exchange and processes by which properties of sea water are mixed. Such oceanic fronts have long been described in secondary school textbooks with the term 'Jokyung water zone (JWC hereafter) or oceanic front', meaning areas where the different currents met, and were related to fishing grounds in the East Sea. However, higher education materials and marine scientists have not used this term for the past few decades; therefore, the appropriateness of the term needs to be analyzed to remove any misconceptions presented. This study analyzed 11 secondary school textbooks (5 middle school textbooks and 6 high school textbooks) based on the revised 2015 curriculum. A survey of 30 secondary school science teachers was also conducted to analyze their awareness of the problems. An analysis of the textbook contents related to the JWC and fishing grounds found several errors and misconceptions that did not correspond with scientific facts. Although the textbooks mainly uses the concept of the JWC to represent the meeting of cold and warm currents, it would be reasonable to replace it with the more comprehensive term 'oceanic front', which would indicate an area where different properties of sea water-such as its temperature, salinity, density, and velocity-interact. In the textbooks, seasonal changes in the fishing grounds are linked to seasonal changes in the North Korean Cold Current (NKCC), which moves southwards in winter and northwards in summer; this is the complete opposite of previous scientific knowledge, which describes it strengthening in summer. Fishing grounds are not limited to narrow coastal zones; they are widespread throughout the East Sea. The results of the survey of teachers demonstrated that this misconception has persisted for decades. This study emphasized the importance of using scientific knowledge to correct misconceptions related to the JWC, fishing grounds, and the NKCC and addressed the importance of transferring procedures to the curriculum. It is expected that the conclusions of this study will have an important role on textbook revision and teacher education in the future.