• 제목/요약/키워드: representative sample

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Grain-Size Trend Analysis for Identifying Net Sediment Transport Pathways: Potentials and Limitations (퇴적물 이동경로 식별을 위한 입도경향 분석법의 가능성과 한계)

  • Kim, Sung-Hwan;Rhew, Ho-Sahng;Yu, Keun-Bae
    • Journal of the Korean Geographical Society
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    • v.42 no.4
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    • pp.469-487
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    • 2007
  • Grain-Size Trend Analysis is the methodology to identify net sediment transport pathways, based on the assumption that the movement of sediment from the source to deposit leaves the identifiable spatial pattern of mean, sorting, and skewness of grain size. It can easily be implemented with low cost, so it has great potentials to contribute to geomorphological research, whereas it can also be used inadequately without recognition of its limitations. This research aims to compare three established methods of grain-size trend analysis to search for the adequate way of application, and also suggest the research tasks needed in improving this methodology 1D pathway method can corporate the field experience into analyzing the pathway, provide the useful information of depositional environments through X-distribution, and identify the long-term trend effectively. However, it has disadvantage of the dependence on subjective interpretation, and a relatively coarse temporal scale. Gao-Collins's 2D transport vector method has the objective procedure, has the capability to visualize the transport pattern in 2D format, and to identify the pattern at a finer temporal scale, whereas characteristic distance and semiquantitative filtering are controversial. Le Roux's alternative 2D transport vector method has two improvement of Gao-Collins's in that it expands the empirical rules, considers the gradient of each parameters as well as the order, and has the ability to identify the pattern at a finer temporal scale, while the basic concepts are arbitrary and complicated. The application of grain sire trend analysis requires the selection of adequate method and the design of proper sampling scheme, based on the field knowledge of researcher, the temporal scale of sediment transport pattern targeted, and information needed. Besides, the relationship between the depth of sample and representative temporal scale should be systematically investigated in improving this methodology.

A Study on Periodontal Disease and Tooth Loss in Metabolic Syndrome Patient (대사증후군 환자의 치주질환과 치아상실에 관한 연구)

  • Kang, Hyun-Joo
    • Journal of dental hygiene science
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    • v.15 no.4
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    • pp.445-456
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    • 2015
  • The aim of this study was to identify an effective control method of metabolic syndrome (MS) and oral diseases by investigating relationship between of MS and periodontal disease, tooth loss of the adult men and woman. We analyzed and concluded as follows, using a nationwide representative sample, in 8,225 middle senior citizens based on raw data of the 5th National Nutrition Survey in 2010, 2012. The data were analyzed by descriptive statistics, chi-squared test, and logistic regression using SAS ver. 9.2 program. The results are as follows, for correlation of metabolic component to periodontal disease, it was found that in men, the periodontal disease odds ratio of the group with abnormal fasting blood glucose increased 1.27 fold (95% confidence interval [CI], 1.04~1.54), and in woman, the odds ratios of the group with abnormal high density lipoprotein cholesterol increased 1.45 fold (95% CI, 1.22~1.72) and the odds ratio of the group with abnormal obesity increased 1.44 fold (95% CI, 1.17~1.77). For correlation of MS to periodontal disease, it was found that the odds ratio of periodontal disease in the woman at-risk group increased 1.55 fold (95% CI, 1.19~2.01) and that of the group with MS increased 2.25 fold (95% CI, 1.68~3.02). For correlation of woman's metabolic component to missing teeth, it was found that the odds ratio of group with abnormal blood pressure increased 1.41 fold (95% CI, 1.10~1.82). For correlation of woman's MS to missing teeth, it was found that the odds ratio of missing teeth in the group with MS increased 1.48 fold (95% CI, 1.07~2.04). It is considered that a public health project comprising preventive and systematic disease management is necessary for controlling MS and oral disease. The findings of the study are expected to lay the foundation for the development of oral health promotion programs.

Determination of cyromazine residues in agricultural commodities using HPLC-UVD/MS (HPLC-UVD/MS를 이용한 농산물 중 Cyromazine의 잔류분석법)

  • Song, Lee-Seul;Kim, Young-Hak;Lee, Su-Jin;Hwang, Young-Sun;Kwon, Chan-Hyeok;Do, Jung-Ah;Oh, Jae-Ho;Im, Moo-Hyeog;Chang, Woo-Suk;Lee, Young-Deuk;Choung, Myoung-Gun
    • The Korean Journal of Pesticide Science
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    • v.16 no.3
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    • pp.202-208
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    • 2012
  • A high-performance liquid chromatographic (HPLC) method was developed to determine residues of cyromazine, a triazine insecticide, in agricultural commodities. Cyromazine was extracted with 90% aqueous methanol from representative crops which comprised brown rice, oyster mushroom, oriental melon, watermelon, and Chinese cabbage. Following to evaporation of methanol in the extract, the aqueous concentrate was acidified to form the protonated cyromazine. Dichloromethane partition was then applied to remove nonpolar co-extractives in the aqueous phase. Strong cation-exchange chromatography using Dowex 50W-X4 resin was employed for final purification of the extract. Cyromazine was successfully separated on a Zorbax SB-Aq $C_{18}$ column showing high retention for polar compounds. Cyromazine was sensitively quantitated by ultraviolet absorption at 214 nm. Limit of quantitation (LOQ) of the method was 0.04 mg/kg irrespective of sample types. Each crops were fortified at 3 different concentrations of cyromazine for recovery test. Mean recoveries from samples fortified at LOQ~2.0 mg/kg in triplicate ranged 80.2~103.3% in five agricultural commodities. Relative standard deviations in recoveries were all less than 6%. A selected-ion monitoring LC/MS method with electrospray ionization in positive-ion mode was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to routinely determine and inspect the residue of cyromazine in agricultural commodities.

Water Quality in a Drainage System Discharging Groundwater from Sangdae-ri Water Curtain Cultivation Area near Musimcheon Stream, Cheongju, Korea (무심천 인근 상대리 수막재배지에서 지하수 사용 후 배출되는 최종 배수로 물의 수질 특성)

  • Moon, Sang-Ho;Kim, Yongcheol;Hwang, Jeong
    • Economic and Environmental Geology
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    • v.48 no.5
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    • pp.409-420
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    • 2015
  • The Sangdae-ri riverside around Musimcheon stream, flowing through Gadeok-myon of Cheongju City, is one of the representative strawberry fields employing water curtain cultivation (WCC) in Korea. In this area, annual groundwater use for WCC has been calculated by a few methods. On the assumption that all the water flowing through the final ditch may be mostly composed of groundwater, the discharge rate in it can be used as a good proxy for assessing the groundwater use. However, in the study area, the final ditch was set up in an unpaved state near and parallel to Musimcheon stream. Under such circumstances, the drainwater is likely to be influenced by infiltration and/or inflow of nearby stream. Hence, we examined whether or not stream water has influenced water flowing out through the final ditch in respect of ion concentrations or field parameters such as T, pH and electrical conductivity (EC) values. The period of measuring field parameters and sample collection was from February 2012 through February 2015. The drainwater in the final ditch did not show the average quality of groundwater, but similar quality of stream water in respect of pH, EC, ion contents and water type. From this, it is suggested that measuring the flow rate of the final ditch should not be directly used for assessing groundwater use in the study area. In addition, because of its sensitivity to ambient temperature, water temperature proved not to be appropriate for estimating the interaction between ditch and stream. For accuracy, additional methods will be needed to calculate mixing ratios between stream and ground water within drainage system.

Development and Validation of Analytical Method for Determination of Biphenyl Analysis in Foods (식품 중 비페닐 분석법 개발 및 유효성 검증)

  • Kim, Jung-Bok;Kim, Myung-Chul;Song, Sung-Woan;Shin, Jae-Wook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.4
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    • pp.459-464
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    • 2017
  • Biphenyl is used as an intermediate in the production of crop protection products, a solvent in pharmaceutical production, and as a component in the preservation of citrus fruits in many countries. Biphenyl is not authorized for use and also does not have standards or specifications as a food additive in Korea. National and imported food products are likely to contain biphenyl. Therefore, control and management of these products is required. In this study, a simple analytical method was developed and validated using HPLC to determine biphenyl in food. These methods are validated by assessing certain performance parameters: linearity, accuracy, precision, recovery, limit of detection (LOD), and limit of quantitation (LOQ). The calibration curve was obtained from 1.0 to $100.0{\mu}g/mL$ with satisfactory relative standard deviations (RSD) of 0.999 in the representative sample (orange). In the measurement of quality control (QC) samples, accuracy was in the range of 95.8~104.0% within normal values. The inter-day and inter-day precision values were less than 2.4% RSD in the measurement of QC samples. Recoveries of biphenyl from spiked orange samples ranged from 92.7 to 99.4% with RSD between 0.7 and 1.7% at levels of 10, 50, and $100{\mu}g/mL$. The LOD and LOQ were determined to be 0.04 and $0.13{\mu}g/mL$, respectively. These results show that the developed method is appropriate for biphenyl identification and can be used to examine the safety of citrus fruits and surface treatments containing biphenyl residues.

An Empirical Study on the Effect of CRM System on the Performance of Pharmaceutical Companies (고객관계관리 시스템의 수준이 BSC 관점에서의 기업성과에 미치는 영향 : 제약회사를 중심으로)

  • Kim, Hyun-Jung;Park, Jong-Woo
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.43-65
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    • 2010
  • Facing a complex environment driven by a decade, many companies are adopting new strategic frameworks such as Customer Relationship Management system to achieve sustainable profitability as well as overcome serious competition for survival. In many business areas, CRM system advanced a great deal in a matter of continuous compensating the defect and overall integration. However, pharmaceutical companies in Korea were slow to accept them for usesince they still have a tendency of holding fast to traditional way of sales and marketing based on individual networks of sales representatives. In the circumstance, this article tried to empirically address current status of CRM system as well as the effects of the system on the performance of pharmaceutical companies by applying BSC method's four perspectives, from financial, customer, learning and growth and internal process. Survey by e-mail and post to employers and employees who were working in pharma firms were undergone for the purpose. Total 113 cases among collected 140 ones were used for the statistical analysis by SPSS ver. 15 package. Reliability, Factor analysis, regression were done. This study revealed that CRM system had a significant effect on improving financial and non-financial performance of pharmaceutical companies as expected. Proposed regression model fits well and among them, CRM marketing information system shed the light on substantial impact on companies' outcome given profitability, growth and investment. Useful analytical information by CRM marketing information system appears to enable pharmaceutical firms to set up effective marketing and sales strategies, these result in favorable financial performance by enhancing values for stakeholderseventually, not to mention short-term profit and/or mid-term potential to growth. CRM system depicted its influence on not only financial performance, but also non-financial fruit of pharmaceutical companies. Further analysis for each component showed that CRM marketing information system were able to demonstrate statistically significant effect on the performance like the result of financial outcome. CRM system is believed to provide the companies with efficient way of customers managing by valuable standardized business process prompt coping with specific customers' needs. It consequently induces customer satisfaction and retentionto improve performance for long period. That is, there is a virtuous circle for creating value as the cornerstone for sustainable growth. However, the research failed to put forward to evidence to support hypothesis regarding favorable influence of CRM sales representative's records assessment system and CRM customer analysis system on the management performance. The analysis is regarded to reflect the lack of understanding of sales people and respondents between actual work duties and far-sighted goal in strategic analysis framework. Ordinary salesmen seem to dedicate short-term goal for the purpose of meeting sales target, receiving incentive bonus in a manner-of-fact style, as such, they tend to avail themselves of personal network and sales and promotional expense rather than CRM system. The study finding proposed a link between CRM information system and performance. It empirically indicated that pharmaceutical companies had been implementing CRM system as an effective strategic business framework in order for more balanced achievements based on the grounded understanding of both CRM system and integrated performance. It suggests a positive impact of supportive CRM system on firm performance, especially for pharmaceutical industry through the initial empirical evidence. Also, it brings out unmet needs for more practical system design, improvement of employees' awareness, increase of system utilization in the field. On the basis of the insight from this exploratory study, confirmatory research by more appropriate measurement tool and increased sample size should be further examined.

Distribution and Interrelationship of Smoking, Drinking, and Physical Exercising among Some Rural Adult, an Application of the Transtheoretical Model (행동수정의 단계적 변화론 모형(Transtheoretical Model)에 의한 일부 농촌성인의 흡연, 음주 및 운동행태 분포와 상호 관련성)

  • Lee, Moo-Sik;Lee, Young-Sung;Shin, Hyun-Hwa;Lee, Kun-Sei;Yoon, Seok-Jun;Jung, Ki-Hweon;Kim, Eun-Young;Chun, Byung-Chul
    • Journal of agricultural medicine and community health
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    • v.25 no.1
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    • pp.113-131
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    • 2000
  • Transtheoretical model of change has been proven very effective in explaining both the acquisition and cessation of many health related behaviors. The objectives of this study were to describe the distribution of smokers by stage of change of smoking, alcoholic drinking, and exercising in rural residents and to develope health promotion strategies. This study was done in Okchun County of Chungbuk Province. The representative sample were 892 residents over 30 years old. The questionnaires of interview included socio-demographic, the six stage distribution of smoking, alcoholic drinking, and exercising. In male, 50.6% of smokers were in the precontemplation stage, 32.5% in the contemplation. In female, corresponding figures were 60.6% and 28.8%. Precontemplation and contemplation stage of drinker were 72.8%, 19.3% in male and 80.3%, 15.5%. Distribution of exercise were 80.6%, 1.8% in male, 87.6%, 1.2% in female, respectively. The stage distribution of smoker, alcoholic drinker, and exerciser was shift to left of the distribution. And the stage distribution was slightly differ with each health behavior. The stage of change with smoking, drinking and exercising was correlated with each other but not concordant. So interventions in rural residents need to take into account the large proportion of precontemplators repeatedly observed among smoker, drinker, and non-exerciser. And intervention strategies of each risk behavior should be different approach. Result of concordance analysis suggest reconstruct validity of the transtheoretical model in our country due to ethnic and sociocultural difference. This results and theory should be tested in prospective intervention studies for seeking the possible gateway of health behavior.

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The Assessment on Health Status of Workers by using HPLP and Sa-sang Constitutional Questionnaire (HPLP와 사상체질설문(四象體質說問)을 이용(利用)한 근로자(勤勞者)들의 건강상태(健康狀態) 평가(評價))

  • Choi Mun-Il;Lee Eun-Kyoung;Kwon So-Hee;Ko Kwang-Jae;Seo Byeong-Yun;Jeoung Jae-Yeal;Jahng Doo-Sub;Song Yung-Sun;Lee Ki-Nam
    • Journal of Society of Preventive Korean Medicine
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    • v.5 no.1
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    • pp.41-56
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    • 2001
  • Overview: The purpose of this study was to evaluate the determinants on the correlation between constitution and health promoting lifestyle profile on the workers. Also, the questionnaire on the HPLP (health promoting lifestyle profile) of Walker(1987) and Sa-sang constitution of Lee(l894) were utilized Methods: Data from a representative sample of 652 workers were analyzed Pearson's chi-square test analysis was utilized to test the explanatory causal model and to determine the direct and indirect effects of independent variables on quality of life. Results: Constitutional distribution among exposed group, were Tae-eum In(43.7%), So-eum In(33.6%), and So-yang In(22.7%). The degree of the subjects practicing health promoting lifestyle, on a scale of 1 to 4, is an average of 2.62, personal relations 2.94, self-realization 2.86, stress management 2.71, nutrition 2.68, responsibility for health 2.37, and exercise 2.21, with personal relations earning the highest points and exercise the lowest As for factors influencing health promoting lifestyle, there is significant difference between sex and age. That is female and higher age. On the difference between constitution and health promoting lifestyle, Tae-eum In is the highest all area except personal relations. So-eum In is the lowest all area except responsibility for health. Conclusions: Tae-eum In totally do health promoting lifestyle well but So-eum In relatively not. On the Study we used the HPLP(health promoting lifestyle profile) on the premise that each person's daily life, the attitude and the practice level to the health have an influence on the health. So in the constitution there is a little differences in the consideration and the practice level and health condition will be different. On this study we finish up by knowing about the health promoting lifestyle. But on next time we will have to go on studying about the sign and the comparison with the result of western and oriental medical health examination to the each constitution on carrying out continuously oriental medical health examination.

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Development of Stand Yield Table Based on Current Growth Characteristics of Chamaecyparis obtusa Stands (현실임분 생장특성에 의한 편백 임분수확표 개발)

  • Jung, Su Young;Lee, Kwang Soo;Lee, Ho Sang;Ji Bae, Eun;Park, Jun Hyung;Ko, Chi-Ung
    • Journal of Korean Society of Forest Science
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    • v.109 no.4
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    • pp.477-483
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    • 2020
  • We constructed a stand yield table for Chamaecyparis obtusa based on data from an actual forest. The previous stand yield table had a number of disadvantages because it was based on actual forest information. In the present study we used data from more than 200 sampling plots in a stand of Chamaecyparis obtusa. The analysis included theestimation, recovery and prediction of the distribution of values for diameter at breast height (DBH), and the result is a valuable process for the preparation ofstand yield tables. The DBH distribution model uses a Weibull function, and the site index (base age: 30 years), the standard for assessing forest productivity, was derived using the Chapman-Richards formula. Several estimation formulas for the preparation of the stand yield table were considered for the fitness index, and the optimal formula was chosen. The analysis shows that the site index is in the range of 10 to 18 in the Chamaecyparis obtusa stand. The estimated stand volume of each sample plot was found to have an accuracy of 62%. According to the residuals analysis, the stands showed even distribution around zero, which indicates that the results are useful in the field. Comparing the table constructed in this study to the existing stand yield table, we found that our table yielded comparatively higher values for growth. This is probably because the existing analysis data used a small amount of research data that did not properly reflect. We hope that the stand yield table of Chamaecyparis obtusa, a representative species of southern regions, will be widely used for forest management. As these forests stabilize and growth progresses, we plan to construct an additional yield table applicable to the production of developed stands.

Determination of Mycotoxins in Agricultural Products Used for Food and Medicine Using Liquid Chromatography Triple Quadrupole Mass Spectrometry and Their Risk Assessment (LC-MS/MS를 이용한 식·약 공용 농산물의 곰팡이독소 분석 및 위해평가)

  • Choi, Su-Jeong;Ko, Suk-Kyung;Park, Young-Ae;Jung, Sam-Ju;Choi, Eun-Jung;Kim, Hee-sun;Kim, Eun-Jung;Hwang, In-Sook;Shin, Gi-Young;Yu, In-Sil;Shin, Yong-Seung
    • Journal of Food Hygiene and Safety
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    • v.36 no.1
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    • pp.24-33
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    • 2021
  • For this study, we surveyed concentrations of 8 mycotoxins (aflatoxin B1, B2, G1, G2, ochratoxin A, fumonisin B1, B2 and zearalenone) in agricultural products used for food and medicine by liquid chromatography-tandem mass spectrometry and conducted a risk assessment. Samples were collected at the Yangnyeong Market in Seoul, Korea, between January and November 2019. Mycotoxins were extracted from these samples by adding 0.1% formic acid in 50% acetonitrile and cleaned up by using an ISOLUTE Myco cartridge. The method was validated by assessing its matrix effects, linearity, limit of detection (LOD), limit of quantification (LOQ), recovery and precision using four representative matrices. Matrix-matched standard calibration was used for quantification and the calibration curves of all analytes showed good linearity (r2>0.9999). LODs and LOQs were in the range of 0.02-0.11 ㎍/kg and 0.06-0.26 ㎍/kg, respectively. Sample recoveries were from 81.2 to 118.7% and relative standard deviations lower than 8.90%. The method developed in this study was applied to analyze a total of 187 samples, and aflatoxin B1 was detected at the range of 1.18-7.29 ㎍/kg (below the maximum allowable limit set by the Ministry of Food and Drug Safety, MFDS), whereas aflatoxin B2, G1 and G2 were not detected. Mycotoxins that are not regulated presently in Korea were also detected: fumonisin (0.84-14.25 ㎍/kg), ochratoxin A (0.76-17.42 ㎍/kg), and zearalenone (1.73-15.96 ㎍/kg). Risk assessment was evaluated by using estimated daily intake (EDI) and specific guideline values. These results indicate that the overall exposure level of Koreans to mycotoxins due to the intake of agricultural products used for food and medicine is unlikely to be a major risk factor for their health.