• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.336-343
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• 2000

Purpose: Thallous-201 chloride produced at Korea Cancer Center Hospital(KCCH) is used in detecting cardiovascular disease and cancer. Thallium impurity can cause emesis, catharsis and nausea, so the presence of thallium and other metal impurities should be determined. According to USP and KP, their amounts must be less than 2 ppm in thallium and 5 ppm in total. In this study, the detection method of trace amounts of metal impurities in $[^{201}Tl]$TICI injection with polarography was optimized without environmental contamination. Materials and Methods: For the detection of metal impurities, Osteryoung Square Wave Stripping Voltammetry method was used in Bio-Analytical System (BAS) 50W polarograph. The voltammetry was composed of Dropping Mercury Electrode (DME) as a working electrode, Ag/AgCl as a reference electrode and Pt wire as a counter electrode. Square wave stripping method, which makes use of formation and deformation of amalgam, was adopted to determine the metal impurities, and pH 7 phosphate buffer was used as supporting electrolyte. Results: Tl, Cu and Pb in thallous-201 chloride solution were detected by scanning from 300 mV to -800 mV Calibration curves were made by using $TINO_3,\;CuSO_4\;and\;Pb(NO_3){_2}$ as standard solutions. Tl was confirmed at -450 mV peak potential and Cu at -50 mV Less than 2 ppm of Tl and Cu was detected and Pb was not detected in KCCH-produced thallous-201 chloride injection. Conclusion: Detection limit of thallium and copper is approximately 50 ppb with this method. As a result of this experiment, thallium and other metal impurities in thallous-201 chloride injection, produced at Korea Cancer Center Hospital, are in the regulation of USP and KP Polarograph could be applied for the determination of metal impurities in the quality control of radiopharmaceuticals conveniently without environmental contamination.

• Restorative Dentistry and Endodontics
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• v.31 no.3
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• pp.192-202
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• 2006

The purpose of this study was to examine the viability of PDL cells in rat molars by using in vivo MTT assay, which was used to compare fast cryopreservation group by liquid nitrogen $(-196^{\circ}C)\;with\;4^{\circ}C$ cold preservation group. A total of 74 Sprague-Dawley white female rats of 4 week-old with a body weight of 100 grams were used. The maxillary left and right, first and second molars were extracted as atraumatically as possible under ketamine anesthesia. Ten teeth of each group were divided as six experimental groups depending upon the preservation. Cryopreservation groups were Group 1 (5% DMSO 6% HES in F medium) Group 2 (10% DMSO in F medium), Group 3 (5% DMSO 6% HES in $Viaspan^(R)$). Group 4 (10% DMSO in $Viaspan^(R)$) which were cryopreserved for 1 week and cold preservation groups were Group 5 (F medium) , Group 6 ($Viaspan^(R)$) at $4^{\circ}C$ for 1 week. Immediate extraction group was used as a control. After preservation and thawing, the in vivo MTT assay was processed. Two way ANOVA and Duncan's Multiple Range Test was performed at the 95 % level of confidence, Another 2 teeth of each group were treated as the same manner and frozen sections $10{\mu}m$ thick for microscopic observation. The value of optical density obtained after in vivo MTT analysis was divided by the value of eosin staining for tissue volume standardization. Group 1, 2 had significantly higher optical density than Group 3 and 4 which had the lowest OD value. Group 6 had higher OD value than in Group 5 (P<0.05). Histological findings of periodontal ligament cell, after being stained with MTT solution were consistent with the in vivo MTT assay results. In this study, the groups which were frozen with DMSO as a cryoprotectant and the groups with F medium showed the best results.

• Korean Journal of Social Welfare Studies
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• v.44 no.3
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• pp.177-206
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• 2013

The Korean government has implemented the senior employment policy as a direct job creation policy since 2004. A realistic discussion of policy alternatives and orientation for this has been given little attention even though senior employment policy has been carried out for the last 10 years and it will be expanded next year. This study tries to examine active labor market policy especially focusing on direct job creation programs and policies for the disadvantaged low-income elderly in OECD countries, and then it suggests some developmental alternatives for senior employment policy based on the study's results. The main results from this analysis are summarized in two points. Firstly, except pension policies, employment policy for older workers in the OECD countries is highly proportional to the tackling of objective factors reducing the demand for older workers (wage subsidies, reduced social security contribution rate etc). And the strategies of improving employability have not been relatively important and direct job creation policy has been marginal. Secondly, employment support policies for the low-income elderly can be divided into three types: support for the low-income elderly, alleviating early retirement and support for full employment according to the criteria which are determined by policy objectives and the social economic index. Korea's employment support policies belong to the type of direct job creation among them. This seems to be due to the fact that the rate of elderly poverty is extremely high and an income security system has not been developed in Korea. However, the policy objective is still uncertain. Therefore, this policy needs to set up clear objectives and establish a proper system for the achievement of its goals. If we focus on the strength of its employment characteristics, we need to modify the policy's plan in the perspective of labor market policy. But if we intend to keep both of the current objectives, it is better for this policy to be divided into two parts: social participation and income supplements. Or it also may be a solution to transform the system into an employment service, a training system which supports participants to move into unsubsidized jobs such as SCSEP in the U. S.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.569-579
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• 2019

In this study, the effect anti-oxidant, anti-inflammatory, and liver protective activity was investigated via quick ultrasonic disintegration of pine pollen using a probe sonicator (PS) followed by the extraction with water, 70% ethanol, and 100% ethanol. The anti-inflammatory effect was studied by measuring the production of nitric oxide (NO) and cytokine in RAW264.7 cells induced with lipopolysaccharides (LPS). The cell toxicity was also checked with an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the experiment was conducted using non-toxic $100{\mu}g/mL$. The NO inhibition rate was highest in the 70% ethanol PS group at $85.99{\pm}0.12%$. Also an excellent efficiency was obtained from the results of interlukin-1 beta ($IL-1{\beta}$) and tumor necrosis factor alpha ($TNF-{\alpha}$), which is related to inflammation-related cytokine, with the respective inhibition rates of 63 and 22%. To examine liver protective activity, HepG2 cells were treated with Taclin, and the generation of glutamic oxaloacetic transaminase (GOT) and lactate dehydrogenase (LDH) was measured in the culture solution. From GOT and LDH generation results, the inhibition rates in the 70% ethanol PS group were 28% and 13%, respectively, which was higher compared to that of using negative control group. Our results suggest that pine pollen extracted in 70% ethanol using PS may be used to develop food products that have anti-aging, anti-inflammatory, and liver protective effects.

• Korea journal of population studies
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• v.11 no.1
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• pp.50-57
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• 1988

This study focused on the anding of Inchon's identity The empirical method and ethnomethodological approaches were used to collect the data. Among members ofcitizen movement groups,government workers,and students who are living inInchon were selected as 613 samples using a purposive sampling method. MultipleClassification Analysis (MCA) and cross-tabulation methods were used in theanalysisThe study of identity in an area is important in terms of providing the solution ofthe problem in a region and social integration of the citizens. The scores of the indexabout Inchon's identity are quite low and more than half of the respondents to allthree groups showed the middle position of the scores from the identity index. By thecharacteristics of the respondents,female,unmarried single,30 years or more,lowerincome groups showed relatively higher identity index scores than other counter-parts . And professional,administrative,clerical workers'identity index scores werehigher than people who work at sales,service,and agricultural sectors. Respondentswith 2 years of college or more,with intentions to donate special monies for cultural, social welfare, environmental reform,persons who want to live in Inchon for along period of time equipped with a stronger identity index.For the character of Inchon's identity,there are no identity,making it fromnow on,capacity or broad-minded city,vanguard pioneer,displeased, Oiversity/multiplicity of the city,defense spirit from foreign invasion,entrancecity from the world in that order. Therefore,it is hard to say what exactly Inchon'simage is in a single word. However,Inchon can be characterized as a diverse citywith capacity to live together without any serious conflicts among citizens who come from Seoul,Kyunggi-Do,Chungchung-Do,Chunla-Do,Kyungsang-Do,and foreign countries including North Korea. These facts imply that Inchon should continue topursue this image as a diverse city with capacity as an identity pursuing towardsworld city and hub city of North East Asia.ty as an identity pursuing towardsworld city and hub city of North East Asia. East Asia.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.367-376
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• 2021

Strawberry cultivation in Korea is grown in greenhouse, but most farms manage their water supply using a timer control method based on the experience of growers. The timer control has problems in that it is difficult to consider the weather condition, the growth stage of crops, and the moisture content of the substrate, so that the crops cannot be managed at an optimal level, and the accuracy of cultivation management are lacking. The watering methods using integrated solar irradiance and substrate moisture contents are control systems that provide eco-friendly and precise water supply considering the growth conditions of crops. The purpose of this study was to compare the combined water supply control with integrated solar irradiance and substrate moisture contents and timer control method in hydroponic cultivation of strawberries using coir, and to set the optimal integrated solar irradiance level for complex water supply control. The irrigation system was automatically watered when it reached 100, 150, 250 J·cm^-2 based on the external solar irradiance, and forced irrigation was performed at a substrate moisture content of less than 60% in all treatments. The amount of irrigation at once was 50 mL. The timer treatment was applied as a control. The smaller the level of integrated radiation to start watering, the greater the daily amount of irrigation. Both the fresh weight and dry weight per plant were higher in the complex irrigation control method than the timer control, and the 100 and 150 J·cm^-2 treatment had the highest fresh weight, and the 100 J·cm^-2 treatment showed a significantly higher dry weight. The yield was also significantly higher in the complex control method than in the timer, and the early yield increased as the level of integrated solar irradiance was smaller. The fresh weight of fruit was the lowest in the timer-controlled irrigation. As a result of this study, the possibility of combined control irrigation method using integrated solar irradiance and substrate moisture content was confirmed for precise water supply management of strawberries in hydroponics.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.2
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• pp.151-163
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• 2019

In recent years, as the population of ear and aged villages has increased, the problem of conflict between rural residents and urban-to-rural migrants has been widespread. For successful rural community, such conflict resolution is more important than anything else. However, if we look at previous studies. It is true that there are many studies that focus on people who are not rural residents or urban-to-rural migrants. This study was conducted to find out the difference of strategies for conflict resolution between rural residents and urban-to-rural migrants. This study derives the factors of conflict based on the contents of previous studies, To see the difference, five strategies were used from the response strategies that were used in the 'Computer Prisoner's Dilemma Contest' held by Axelrod (2009). I would like to know what kind of strategies of rural residents and urban-to-rural migrants. All analyzes were done using SPSS 22.0 for Windows, and the results of each conflict resolution analysis showed that the indigenous conflicts were low All. Among the causes of conflict, the highest level of conflict was caused by the 'rural residents who did not understand urban culture'. The strategy is the most used, followed by tit for tat Strategy, and all-c strategy, in that order. However, It is not uncommon for employers to use a work-type strategy, and it can be seen that the strategy changes depending on the cause. As can be seen from the above results, The conflict resolution strategies are almost similar strategies. It can be seen that conflict resolution strategy is used differently according to personality. The purpose of this study is to investigate the differences in conflicts in the rural areas. In particular, it is meaningful to examine the choice of solution strategies based on game theory through reviewing prior research and eliciting actual conflict factors in the field. Successful rural settlement can be achieved not through stakeholder competition but through mutual cooperation by gaining cooperation to the other side. Mutual cooperation is more profitable than betrayal in various conflict situations. The secret to maintaining and communicating smoothly is not to use the other person to fill his or her selfish interests, but to reject it for profit, but to draw cooperation from the other party.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.110-116
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• 2019

This study was conducted to determine the effects of a pre-planting fertilizers with various $NH_4{^+}:NO_3{^-}$ ratios in a coir dust:peatmoss:perlite (3.5:3.5:3.0, v/v/v) medium on the growth of hot pepper (Capsicum annuum L. cv. Nokkwang) plug seedling. Nitrogen levels were fixed to $300mg{\cdot}L^{-1}$ and the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, and 100:0. The 50-cell trays were filled with treatment media containing pre-plant fertilizers, then seeds were sown. After seeds were germinated, the trays were moved to greenhouse and seedlings were feed with 13-2-13 and 20-9-20 fertilizers, alternatively. The changes in pH and EC were measured every week and soil solution for nutrient concentrations were analyzed in week 0, 3, and 7. The measurements of seedling growths as well as analysis of tissue nutrient contents were also conducted in week 7. The varied $NH_4{^+}:NO_3{^-}$ ratios did not influence on the pHs of root media after incorporation of pre-planting fertilizers, but the ECs were heightened as proportion of $NH_4{^+}$ to $NO_3{^-}$ were elevated. During the raising of seedlings, the pHs rose over time in the treatments of 0:100 and 27:73 ($NH_4{^+}:NO_3{^-}$). The concentrations of all macro-elements in root media decreased gradually as seedlings grew in all treatments. The seedling growths 7 weeks after seed sowing were the highest in the treatments of 27:73 and 50:50 ($NH_4{^+}:NO_3{^-}$) and those became worse in the treatments of higher $NH_4{^+}$ ratios than 73%. In terms of inorganic element contents based on the dry weight of above ground tissue, the treatment of 0:100 showed the lowest content of Ca, Mg, Na, Cu, Mn, and Zn. Based on the results, it is desired that $NH_4{^+}$ ratio in pre-planting fertilization is maintained to be 50% or less for the raising of hot pepper plug seedlings.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.5
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• pp.14-27
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• 2019

This study presents a plan for a memorial park that respects the characteristics based on the historical facts for the concept of space of the Gwangju Hospital of Korea Army and the location of the 505 Security Forces, which were designated as historic sites after the 5-18 Democratization Movement. The Gwangju Metropolitan City as it is the location of the 5-18 historic sites, is taking part in the 5-18 Memorial Project, and plans to establish a city park recognizing the historic site of the 5-18 Democratization Movement, which has been preserved only as a memory space to this point. The park is promoting a phased development plan. This study suggests that the 5-18 historic sites can be modernized and that social consensus can establish the framework of the step-by-step planning and composition process to ensure the plans for the space heals wounds while preserving the history. In this paper, we propose a solution to a problem. We solve the approach for space utilization through an analysis of precedent research and planning cases related to park planning at historical sites. In addition to exploring the value of the site, we also describe the space utilization strategy that covers the historical characteristics and facts while maintaining the concept of park planning. As a result of the research, the historic site of the Gwangju Hospital of Korea Army is planned as a park of historical memory and healing in order to solve the problems left behind by the 5-18 Democratization Movement. The historic site of the 505 Security Forces was selected as an area for historical experiences and a place for learning that can be sympathized with by future generations of children and adolescents in terms of expanding and sustaining the memory of the 5-18 Democratization Movement. In the planning stage, the historical sites suggested the direction of space utilization for representation as did the social consensus of citizens, related groups, and specialists. Through this study, we will contribute to construction of a memorial park containing historical values in from 5-18 historic sites. It is meaningful to suggest a direction that can revitalize the life of the city as well as its citizen and can share with the history with future generations beyond being a place to heal wounds and keep alive the memory of the past.

• Korean Journal of Heritage: History & Science
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• v.54 no.2
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• pp.38-55
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• 2021

Cherwon Castle is located in Pungcheonwon, Cherwon, in the center of the Korean Peninsula. Currently, it is split across the Demilitarized Zone (DMZ) between the two Koreas. It attracts attention as a symbol of inter-Korean reconciliation and as cultural heritage that serves as data in making important policy decisions on the DMZ. Despite its importance, however, there has not been sufficient investigation and research done on Cherwon Castle. This is due to the difficulty involved in investigation and research and is caused by the site's inaccessibility. As a solution, the current investigative methods in satellite and aerial archeology can be applied to interpret and analyze the structure of Cherwon Castle and the features of its inner space zoning. Cherwon Castle was built on the five flat hills that begin in the northern mountainous hills and stretch to the southwest. The inner and outer walls were built mainly on the hilly ridges, and the palace wall was built surrounding a flat site that was created on the middle hill. For each wall, the sites of the old gates, which were erected in various directions , have been identified. They seem to have been built to fit the direction of buildings in the castle and the features of the terrain. The castle was built in a diamond shape. The old sites of the palace and related buildings and landforms related to water drainage were identified. It was verified that the roads and the gates were built to run from east to west in the palace. In the spaces of the palace and the inner castle, flat sites were created to fit different landforms, and building sites were arranged there. Moreover, the contour of a reservoir that is believed to be the old site of a pond has been found; it lies on the vertical extension of the center line that connects the palace and the inner castle. Between the inner castle and the outer castle, few vestiges of old buildings were found, although many flat sites were discovered. Structurally, Cherwon Castle is rotated about nine degrees to the northeast, forming a planar rectangle. The planar structure derives from the castle design that mimics the hilly landform, and the bending of the southwestern wall also attests to the intention of the architects to avoid the wetland. For now, it is impossible to clearly describe the functions and characters of the building sites inside the castle. However, it is believed that the inner castle was marked out for space for the palace and government offices, while the space between the outer and inner castle was reserved as the living space for ordinary people. The presence of the hilly landform diminishes the possibility that a bangri (grid) zoning system existed. For some of the landforms, orderly zoning cannot be ruled out, as flat areas are commonly seen. As surveys have yet to be conducted on the different castles, the time when the walls were built and how they were constructed cannot be known. Still, the claim to that the castle construction and the structuring of inner spaces were inspired by the surrounding landforms is quite compelling.