• Journal of Korean Society on Water Environment
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• v.34 no.3
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• pp.316-327
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• 2018

Liquid fertilizers made from livestock manure contain high concentrations of nitrogen and phosphorus and thus are used as a fertilizer. However, excessive use of liquid fertilizer causes eutrophication of agricultural land and nonpoint source pollution. In this study, as a means of lowering the nutrient concentrations, struvite ($MgNH_4PO_4{\cdot}6H_2O$) production from the liquid fertilizer was investigated. When liquid fertilizers produced in Gyeonggido were analyzed, its characteristics differed by region and season, but the phosphorus concentration was commonly lower than that of nitrogen. When $K_2HPO_4$ and $MgCl_2$ were added to the liquid fertilizers, the optimal pH for struvite formation was pH 9.5. For environmentally friendly sources of magnesium and phosphate, ferronickel slag (FNS) and sewage sludge ash (SSA) were suspended in deionized water and extracted by sulfuric acid with various mass ratios. The optimum conditions for extracting FNS and SSA were 4.0 M sulfuric acid and 0.35 mass ratio of sulfuric acid to sewage sludge ash, respectively. For forming struvite, 0.233 L of SSA leachate (SSAL) was added into 0.3 L of liquid fertilizer containing 2,586 mg/L of ammonia and 110 mg/L of phosphate, pH was then adjusted to pH 9.5 using 10 M of NaOH. Afterwards 0.333 L of FNS leachate (FNSL) was added to this mixed solution. After a reaction for 1 hr at room temperature, the remaining concentrations of magnesium, ammonium, and phosphate were less than 50 mg/L, 500 mg/L and 150 mg/L, respectively, and 30 g of precipitates were obtained, most of which were struvite.

• Journal of the Korean Regional Science Association
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• v.31 no.2
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• pp.47-61
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• 2015

The purpose of this study to empirical analysis of the effects of distance-decay for the relocated firms in the Seoul Metropolitan Area(SMA). In addition, this study was constructed distance-decay function for the relocated firms by industrial types using a general distance-decay function. The data of relocated firms in the SMA extracted from the spatial database which was constructed in an previous research. The industrial type divided into 3 parts which are construction, manufacturing, and service. The result of empirical analysis by each industrial type of the effect of distance-decay, the explanatory power($R^2$) of the each function were all high. In the construction, the adjusted $R^2$ of the distance-decay function was 0.728, the manufacturing was 0.802 and the service was 0.812. It means the effect of distance decay for the relocated firms in construction industrial type more big than the effects of distance decay for the manufacturing and service industrial types.

• Korean Journal of Community Nutrition
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• v.20 no.4
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• pp.273-280
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• 2015

Objectives: The study aimed to examine whether healthy diet score was associated with stress and social support among 472 Chinese college students in Korea. Methods: The study participants were 472 (187 male, 285 female) Chinese college students in Gyeong-gi area. From April 2013 to Oct 2013, participants were asked to fill out questionnaires on healthy diet score (20 questions), stress (20 questions), and social support (20 questions). Each question was scored by a 5-point Likert scale (total scores of each questionnaire were ranged from 20 to 100). Questions on healthy diet were sub-categorized as 'Healthy food eating (HFE)', 'Healthy eating habits (HEH)', and 'Avoidance of unhealthy food (AUF)'. Reliability test was conducted with Cronbach's ${\alpha}lpha$ (${\alpha}=0.79$). Results: Healthy diet score was higher in participants who stayed longer in Korea, who spoke Korean language fluently, and who assessed his or her own health status as very good. Adjusted means of healthy diet scores were estimated after adjusting for age, gender, body mass index, duration of staying, and Korean language fluency. According to tertile categories, participants with low tertile stress but high tertile social support showed the highest score of healthy diet ($72.59{\pm}1.45$), whereas participants with high tertile of stress but low tertile of social support had the lowest score of healthy diet ($59.22{\pm}1.54$). As for the three sub-categories of healthy diet score, the score of HFE increased as the score of social support increased. Conclusions: Our findings suggested that social support system is beneficial to alleviate stress and to improve healthy diet score.

• Health Policy and Management
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• v.22 no.1
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• pp.65-84
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• 2012

Because of the rising healthcare costs, there is a growing need for developing efficiency indicators for medical resources use and measuring efficiency of healthcare providers and healthcare systems using them. In this study, we aimed to develop efficiency indicators for medical resources use by means of Delphi technique. We systematically reviewed the existing measures of medical resource use. Thirty nine indicators were selected as a candidates across the six domains: medical personnel, medical equipment, medical facilities, ethical management, resource efficiency, and drug use. To develop efficiency indicators with professional consensus, a 2-round Delphi survey was conducted among 29 professional experts. The following indicators were selected based on the Delphi survey results: adjusted number of the patient per day and level of the nurse number medical personnel in medical personnel domain; the number of the scan a professional physician and the quality of the scan in medical equipment domain; bed utilization rate in medical facility domain; drug price reported pharmaceutical price by medical institutions, medical fee billing transparency, and medical care appropriateness in ethical management domain; costliness index in resource efficiency domain; and utilization of high cost drug and items per prescription in drug use domain. The efficiency indicators could provide valid information about efficiency of healthcare providers and healthcare systems with respect to their resources use and facilitate policies to improve their efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5097-5104
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• 2013

To derive implication for marketing strategy for Korean cosmetic products in China, an analysis was conducted on the difference in quality perception and purchase behavior between two groups of Chinese women classified by their awareness of Korean Wave. Analytical methods including k-means clustering method, independent samples t-test, factor analysis were applied on the survey results of Chinese women residing in Guangzhou city. The positive impact of Korean Wave on quality perception and brand image is much stronger for higher awareness group, compared against for lower awareness group, that leads to higher product satisfaction and willingness to recommend purchases. Thus, marketing strategies need to be adjusted based on the difference in customers awareness of Korean Wave. However, the low price is the primary inducement for purchases for both groups, increased efforts to enhance brand image and product quality as premium products is strongly required, together with the utilization of Koran Wave.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.59-66
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• 2017

In this paper, to protect the piping in nuclear power plants and various plant facilities, we have developed a damper using the friction method and carried out a study to analyze the performance. Friction typed damper means a device for attenuating vibration by generating a frictional force to the bearing and the shaft by applying a compressive force to the MER-Spring. In order to analyze the performance of the damper, the properties of MER-Spring and friction materials were analyzed, a study on the effects of friction was carried out, and the behavior of this equation was established. And, to determine whether deformation of the material and to examine the reliability of the behavior equation established, prototypes was produced and, through a performance test and finite element analysis of a damper made of specimens, they were analyzed. As a result, it is noted that the reliability of the material was confirmed, the coefficient of friction have to be adjusted according to the velocity, cyclic loading test and finite element analysis results show exhibits excellent results. In addition, a review of the dynamic loads in the future shall be performed for the usage in more broad fields.

• Journal of the Korean Home Economics Association
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• v.43 no.3 s.205
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• pp.199-219
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• 2005

The purpose of this study was to examine how life-changes after divorce, individual resources, and interpersonal resources affect post-divorce adjustment. Especially it focuses on gender differences. Data were collected from 114 divorced men and 112 divorced women in their 20s and 30s with the inclusion criteria of 1) having hen divorced for at least 6 months but less than 5 years, and 2) not having remarried after divorce. AH divorced men and women were interviewed with self-report questionnaires. The analysis included frequencies, means, t-test, crosstabs, and hierarchical multiple regression models. The major findings were as follows. 1) Divorced women were better adjusted than divorced men. 2) Fnancial satisfaction and health problems were important factors for both divorced men and women. 3) There were gender differences in the variables that affected post-divorce adjustment. Social support and significant others' attitude toward divorce influenced post-divorce adjustment for divorced men. For divorced women, negative change in financial circumstances, their own attitude toward divorce and divorce initiation found significant. This study showed that there were gender differences in the factors affecting Post)divorce adjustment. The findings of this study suggest that a program for supporting divorced men and women should consider gender differences.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.444-450
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• 2014

PURPOSE. To compare the accuracy of marginal and internal adaptation of zirconia (Zr) copings fabricated on anatomic (A), semi-anatomic (SA) and non-anatomic (NA) occlusal surface preparations. MATERIALS AND METHODS. 45 extracted bicuspid teeth were prepared for receiving zirconia crowns, with different occlusal preparation designs A=15, SA=15 & NA=15. The Zr copings were fabricated by using CAD4DENT, CAD/CAM. The copings were adjusted, cemented and were cross sectioned centrally from buccal cusp tip to lingual cusp tip into mesial and distal halves. The copings were examined under electron microscope at ${\times}200$ magnification and the measurements were recorded at 9 predetermined areas in micrometers. RESULTS. Overall mean gap values for the three groups was found to be $155.93{\pm}33.98{\mu}m$ with Anatomical Occlusal preparation design having the least gap value of $139.23{\pm}30.85{\mu}m$ showing the best adaptation among the groups. Post Hoc Tukey's test showed a statistically significant difference (P=.007) between the means of gap for A & NA preparation designs. Measurements recorded at 9 predetermined points showed variations for the three groups. CONCLUSION. Anatomical occlusal preparation designs resulted in better marginal and internal adaptation of Zr copings. There is a considerable variation between the measured marginal and internal gap values for the Zr copings fabricated by the (CAD4DENT-CAD/CAM). This variation may be associated with the lack of standardization of the preparation of teeth, computerized designing of the coping for each tooth, cement used, uniform pressure application during the cementation of the copings, sectioning of the copings and the microscopic measurements.

• Journal of Plant Biology
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• v.5 no.2
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• pp.13-16
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• 1962

Without annual ring, the bamboo can not measured by ordinary mensuration method. Other methods yet tried failed to prove the reliability. That means, as often pointed out, that the bamboo lumbering (including forest management) is not free from being precarious. Noting the fact, this author performed a serieds of comparative observations on a group of bamboos in different stages of growth in order to find out if there is any surer mensurability. A conclusion has been reached that the external feature of joints of branch has close connection with the age of bamboo, that the joints of the third major branch counting from the ground have, as shown in the first table, the most probability, its mean being 94.3 per cent, and that those in ages of 3 to 5 have the probability of 100 per cent, showing the far greater accuracy as compared with those in older ages. The above conclusion needs to be adjusted with the following findings; 1) When observed disregarding the joint-tongue(the remainder of the preceeding year's sheath), the major branches show no better probability than the minor ones. 54 to 78 per cent of them shows no difference between them. Probability is averaged by 60 per cent. 2) When in spring the old sheaths drop away from the joints, the new ones sprout out in their places and consequently the joints present an appearance of a kind of joint-ring. But since this joint-ring does not always exactly represent the plant age, some other method must be sought after to count the age. This author noticed what is called "joint-tongue" the tongue-like part of triangle shape which remains at the base of the sheath of the fallen leaf. A fact was ascertained that when the number of the joint-ring coincides with that of the remaining joint-tongue, it exactly indicates the age of the plant.the plant.

• Journal of the Korea Concrete Institute
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• v.13 no.3
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• pp.294-300
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• 2001

The effectiveness of bottom ash on the mechanical and physical properties of Controlled Low-Strength Material(CLSM) is investigated in this study, CLSM is defined by the ACI Committee 229 as a cementitious material that is in a flowable state at the time of placement and having a specified compressive strength of 83 kgf/$\textrm{cm}^2$ or less at the age of 28 days. This study was undertaken on the use of bottom ash as a fine aggregate in CLSM. Four different levels of bottom ash with fly ash contents, 25%, 50 %, 75%, 100%, are investigated. Laboratory test results conclude that inclusion of bottom ash increases the demand for mixing water in obtaining the required flow. However, the sand was reduced because it was adjusted to maintain a constant total volume. Miかe proportions were developed for producing CLSM at three 28-day strength levels: removal with tools (less than 7 kgf/$\textrm{cm}^2$), mechanical means (less than 20 kgf/$\textrm{cm}^2$), and power equipment (less than 83 kgf/cm\`). The physical and mechanical properties supports the concept that by-product bottom ash can be successfully used in CLSM.