• Title/Summary/Keyword: sampling points

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Characteristics of Groundwater Quality in Bedrock and Tailing Dumps at the Abandoned Dalcheon Mine Area (달천 폐광산 지역에서 광미적재지와 기반암 지하수의 수질특성 연구)

  • Yang, Sung-Il;Kang, Dong-Hwan;Kim, Tae-Yeong;Chung, Sang-Yong;Kim, Min-Chul
    • Economic and Environmental Geology
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    • v.41 no.1
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    • pp.47-56
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    • 2008
  • pH and Eh were measured at 25 points in the abandoned Dalcheon mine. And, major ion components $(Na^+,\;K^+,\;Ca^{2+},\;Mg^{2+},\;Cl^-,\;SO_4^{2-},\;CO_3^{2-},\;HCO_3^-)$ were analyzed through groundwater sampling at 41 points. pH and Eh were measured the highest concentration in serpentinite area. And, pH was between weak alkaline and intermediate values in study area. Groundwater in study area was dominated oxidation-reduction environment caused by reaction with carbonate rock. Because sulfur components contained in carbonate, serpentinite, arsenopyrite and pyrite was dissolved by groundwater, $SO_4^{2-}$ component was high in study area. And $Ca^{2+},\;Mg^{2+}$ of cations were high. Correlation coefficients of ion components in tailing dumps were 0.95 between $Ca^{2+}\;and\;SO_4^{2-}$, 0.86 between $Ca^{2+}\;and\;Mg^{2+}$, 0.85 between $Mg^{2+}\;and\;SO_4^{2-}$. Correlation coefficients of ion components in bedrock were 0.86 between $Mg^{2+}\;and\;SO_4^{2-}$, 0.68 between $Ca^{2+}\;and\;SO_4^{2-}$. Concentration range of $Ca^{2+}$ in tailing dumps was $6.85{\sim}323.58mg/L,\;and\;3.18{\sim}207.20mg/L$ in bedrock. Concentration range of $SO_4^{2-}$ in tailing dumps was $21.54{\sim}1673.17mg/L,\;and\;2.04{\sim}1024.64mg/L$ in bedrock. By the result of Piper diagram analysis with aquifer material, groundwater in tailing dumps was $Ca-SO_4$ type. Groundwater quality types with bedrock material were Mg-$SO_4$ and Mg-$HCO_3$ types in serpentinite area, Ca-$HCO_3$ type in carbonate area, Na-K and $CO_3+HCO_3$ types in hornfels, respectively. As a result of this study, groundwater in tailing dumps were dissolved $Ca^{2+},\;Mg^{2+}\;and\;SO_4^{2-}$ components with high concentration. Also, these ion components were transported into bedrock aquifer.

A Study of the Relation of Stress to Oral Parafunctional Habits of Male High School Students (일부 지역 남자 고등학생들의 스트레스와 구강악습관과의 관련성 연구)

  • Jung, Yu Yeon;Hong, Jin Tae
    • Journal of dental hygiene science
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    • v.13 no.4
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    • pp.471-479
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    • 2013
  • This study is trying to grasp the stress of the male high school students and the correlation between the stress according to the academic and economic level and oral parafunctional habits, emphasizing the need for the education of oral parafunctional habits, providing the basic data in order to accomplish correctly until the oral health of the oral maxillofacial region. From May 2013 till July 2013, a self administered survey was conducted by the selected by convenience sampling from subjects of 1, 2 grade of two high school located in Chungnam, Korea. The study results were as follow: 1) Among five areas of stress, the stress of school life was the highest as 2.11 points and the stress of home problem was the lowest as 1.51 points; 2) the stress by class showed that grade 2 was higher than grade 1 in all areas. The stress of the school life (2.21) (p<0.01), interpersonal relationship (p<0.01), and own problem (p<0.05) showed the significant difference; 3) The significance analysis results between the five areas of stress according to the stress of latent variable and the oral parafunctional habits all showed the significant difference (p<0.001). The correlation between the stress and the oral parafunctional habits showed a weak negative correlation as -0.30, and the stress of the school life, own problem, environment problem, and interpersonal relationship showed very strong correlations more than 0.7; 4) Fit measures test result of stress, academic level, and family economic level model all showed more than 0.9 in good of fit index, adjusted goodness of fit index, normed fit index and root mean square residual and root mean square error of approximation values is all estimated less than 0.1, so it showed good model. From this study, it can be concluded that there is the correlation between stress and oral parafunctional habits.

A study of pain perception related to IV therapy in hospitalized preschool children and their mothers (정맥주사와 채혈시 학령전기 아동과 어머니가 인지하는 동통)

  • 임지영
    • Journal of Korean Academy of Nursing
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    • v.22 no.1
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    • pp.49-67
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    • 1992
  • Most hospitalized children will experience physical pain as well as psychological distress. Preschool children's pain perception related to painful procedures can increase due to elevated anxiety and fear because they do not have understanding logical of their disease and hospitalization. In particular, they are distressed about needle - related procedures which are feared because they are seen to be a cause of bodily damage. This descriptive study attempted to identify pain perception levels in preschool children and their mothers. A self-reporting measurement and behavioral observation were used to collect the data. A total of 25 hospitalized preschool children and their mothers were investigated and data were collected about 60 painful procedures. Data collection was carried out by the researcher and two trained investigators from November first to December tenth. Three insruments were used to collect the data : Faces Pain Rating Scale(FPRS) developed by Beyer was used to measure the degree of preschool children's pain perception about painful procedures. The Visual Analogue Scale(VAS) devised by Huskisson was used to assess the degree of mothers' pain perception about their children's painful procedures. A Pain Behavioral Checklist based on the Procedure Behavior Check List by LeBaron and Zelter and modified by the researcher was used to observe behaviors of preschool children, their mothers, and nurses when the painful procedures took place. The data were analyzed by an SPSS program, and were tested using real numbers, percentages, Pearson correlation coefficient, t-test, and ANOVA. The results of this study are as follows : 1. Of all the painful procedures, the mean score for the FPRS for the preschool children's pain perception was 4.02 points, and the mean score for the VAS of mothers' pain perception was 10.92 points. 2. A Positive correlation which was statistically significant was found between the pain perception of preschool children and their mothers (r=.53, p<.01). that is, the higher the children's pain perception was, the higher their mothers' pain perception was. 3. The characteristics of the painful procedures related with children's pain perception as follows : The type of painful procedure was found to be statistically significant (F=23.44, p<.01), Among the three procedures Ⅳ starting was found to be perceived as the most painful procedures to the children. The greater the number of times that the procedure had been done, the higher the pain perception was (F=4.44, p<.01), and the longer the duration of the procedure, the higher the pain perception wa(r=.30, p<.05). Pain perception in the treatment room was higher than in the children's room(t=6.30, <.01), pain perception in the mother's presence was the higher than when the mother was not present (t=2.91, p<.01). 4. The characteristics of the painful procedures related with the mothers' pain perception as follows : The type of painful procedure was found to be statistically significant(F=6.01, p<.01). Among the three procedures Ⅳ sampling was found to be perceived as the most painful procedures to the mothers. The greater the number of times that the procedure had been done, the higher the pain perception was (F=5.95, p<.01), and the longer the duration of the procedure, the higher the pain perception was (r=.31, p<.05). Pain perception in the treatment room was higher than in the children's room (t=3.51, p<.01), but pain perception in the mother's presence showed statistically significant no difference. 5. Of all of the 19 children's behaviors during the painful procedures, the most frequent behaviors observed Were as follows in order of frequency “crying”, “screamirig”, “facial grimacing”, “physical resistance”, Of all of the nine methers' behaviors, the most frequent by observed in “console children”, “hold children”, “applaud children”, Of all of the 11 nurses' behaviors during the painful procedures, the mast frequent in order were “smiling”, “physical restraint”, “console children”, “praise children”. 6. A positive correlation between children's and mothers' pain perception and children's behaviors was found to be statistically significant (r=.65, p<.01, r=67, p<.01). Also the relationship between children's and mothers' pain percertion, and mothers' behavior was found to be statistically significant (r=.57, p<. 01, 4=.60, p<.01). The relationship between children's pain perception and nurses' behaviors was also found to be statistically significant (r=.46, p<.01), but there was difference between mothers' pain perception and nurses' behaviors.

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Spatial Variation Analysis of Soil Characteristics and Crop Growth across the Land-partitioned Boundary II. Spatial Variation of Soil Chemical Properties (구획경계선(區劃境界線)의 횡단면(橫斷面)에 따른 토양특성(土壤特性)과 작물생육(作物生育)에 관한 공간변이성(空間變異性) 분석연구 II. 토양(土壤) 화학성(化學性)의 공간변이성(空間變異性))

  • Park, Moo-Eon;Yoo, Sun-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.4
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    • pp.257-264
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    • 1989
  • In order to study spatial variability of soil chemical properties across the land-partitioned boundary on Hwadong silt clay loam soil (Fine clayey, mixed, mesic family of Aquic Hapludalfs) in the experimental fie ld of the wheat and Barley Research Institute in Suwon, all measured data were analyzed by means of kriging, fractile diagram, smooth frequency distribution, and autocorrelation. Sampling for soil chemical property analysis was made at 225 intersections of 15x 15 grid with 10m interval from three soil depths (0-10cm, 25-35cm, 50-60cm) in the seven patitioned fields. 1. The coefficient of variance (CV) of various chemical properties varied from 5.4 to 72.7%. Soil pH was classified into the low variation group with CV smaller than 10%, while the other chemical properties belonged to the medium variation group with C.V. between 10 and 100% 2. The approximate number of soil samples for the determination of various chemical properties with error smaller than 10% were two for pH, ten for CEC, 15 for exchangeable Ca, 32 for total nitrogen content, 39 for exchangeable Mg, 40 for exchangeable K, 61 for exchangeable Na, 82 for organic matter content, 212 for available phosphate,. 3. Smooth frequency distribution and fractile diagram showed that available phosphate was in log-normal distribution while others were in normal distribution. 4. Serial correlation analysis revaled that the soil chemical properties had spatial dependence between two nearest neighbouring grid points. Autocorrelation analysis of chemcial properties measured between the serial grid points in the direction of south to north following land-partitioned boundary showed that the zone of influence showing stationarity ranged from 20 to 50m. In the direction of east to west accross land-partitioned boundary, the autocorrelogram of many chemical properies showed peaks with the periodic interval of 30m, which were similar to the partitioned land width. This reveals that the land-partitioned boundary causes soil variability.

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Kriging of Daily PM10 Concentration from the Air Korea Stations Nationwide and the Accuracy Assessment (베리오그램 최적화 기반의 정규크리깅을 이용한 전국 에어코리아 PM10 자료의 일평균 격자지도화 및 내삽정확도 검증)

  • Jeong, Yemin;Cho, Subin;Youn, Youjeong;Kim, Seoyeon;Kim, Geunah;Kang, Jonggu;Lee, Dalgeun;Chung, Euk;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.37 no.3
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    • pp.379-394
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    • 2021
  • Air pollution data in South Korea is provided on a real-time basis by Air Korea stations since 2005. Previous studies have shown the feasibility of gridding air pollution data, but they were confined to a few cities. This paper examines the creation of nationwide gridded maps for PM10 concentration using 333 Air Korea stations with variogram optimization and ordinary kriging. The accuracy of the spatial interpolation was evaluated by various sampling schemes to avoid a too dense or too sparse distribution of the validation points. Using the 114,745 matchups, a four-round blind test was conducted by extracting random validation points for every 365 days in 2019. The overall accuracy was stably high with the MAE of 5.697 ㎍/m3 and the CC of 0.947. Approximately 1,500 cases for high PM10 concentration also showed a result with the MAE of about 12 ㎍/m3 and the CC over 0.87, which means that the proposed method was effective and applicable to various situations. The gridded maps for daily PM10 concentration at the resolution of 0.05° also showed a reasonable spatial distribution, which can be used as an input variable for a gridded prediction of tomorrow's PM10 concentration.

The relationship between students' perceptions and practicability of the "Me and My Family Relations" unit and Family strength among middle school students (나와 가족관계' 단원에 대한 중학생의 긍정적 인식, 실천성 인식과 가족건강성)

  • Cho, Byung-Eun;Jung, Sun-Hee
    • Journal of Korean Home Economics Education Association
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    • v.19 no.1 s.43
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    • pp.99-114
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    • 2007
  • This study aims at investigating how middle school students perceive the content of the 'Me and My Family Relations' unit in the technology and home economics textbook, act on such perceptions and how this connects with their healthy family relations. In addition, the study also points at inquiring into what kind of differences and mutual influences can be found in the above-mentioned three factors according to family environment. With this objective. this research has analyzed survey data conducted on 401 7th grade middle school students residing in Incheon Greater city, collected by the random sampling method. The findings are as follow: First, the students were found to have positive perceptions on the 'family relations and communication' unit in the technology and home economics text book. However. they were also found to perceive that the content was not as realizable in their everyday family lives. Second, the number of students who perceived their family lives to be healthy was found to be quite high. The students perceived their family lives to be healthy projecting from such aspects as the degree of gratification and affection, extent of family bonding, communication patterns, and problem solving abilities, in the same order. In addition, the higher the families' socio-economic level, and in the cases that the students had working mothers and the fathers held higher degrees, the degree to which the families were perceived to be healthy was higher. Third, in investigating the influence that such factors as the students' family environment, the degree that students perceived the text book content positively, and the degree that the students perceive the content to be realizable have on healthy family relations, among these factors, the students' perceived degree of how healthy their family relations are had the most bearing over the above-mentioned factors. The second influential factor on how healthy family relations are was the family's affectional environment, found to be more influential than such factors as family type, the mother's employment status, living standards, and the parents' educational level. On the other hand, the perceived level of realizability was found to have a lower influence on the students' family relations than the perceived positivity.

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A study on physical examination of middle school students (중학교 체질검사 실태에 관한 연구)

  • Park, Sung-Hee
    • Journal of the Korean Society of School Health
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    • v.14 no.1
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    • pp.131-143
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    • 2001
  • The primary aim of this dissertation is to contribute to the improvement of methods in physical examination by providing quality information for the current school system and advice for improving status. Present status, controversial points and possible remedies in physical examination were analyzed on a frequency and percentage basis. An $x^2$-test was used to verify the statistics between the results from the examination and each variable. In case of multiple categories of variables, an $x^2$ cs was adopted. Chronological data as well as both total and sampling physical examination data verified the statistics using an $x^2$-test. This thesis is based both on the data from middle school health care specialists in Gyunggi Province and on the analysis of physical examinations reported from local schools to the municipal education agency from 1997 to 1999. The results of the study are as follows: First, according to the survey, only 29.0% of the total schools had their school doctors examine all the students while most of the educational institutions failed to implement the whole process of physical examination on the list. It also turned out that the more students the schools have, the lower the rate of implementation of physical examination by school doctors(p=0.014). Second, the average time a school doctor spends for checkup turned out to be approximately 1.7 minutes per student This means that the quality of the physical examination is not guaranteed in the process. Third, 47.7% of those surveryed say that a dental examination was performed, each taking 21.24 seconds on average. In addition, it shows that some 31.5% wanted to have a task force team for dental checkups at the local health center. Given the fact that dental caries among students is progressively on the rise, the dental health centers that are now set up in some elementary schools should be expanded to cover the whole educational institution in order to raise awareness of the importance of dental care. Fourth, 48.5% of those surveyed say that a comprehensive physical examination should be adopted to promote the health of high schoolers. Since it takes a lot of public funds to implement a comprehensive method, it is essential to make sure that in-depth studies should be based on the frequency and methods of physical examination. Fifth, regarding such diseases among 3rd year middle school students in 1999, statistics shows that there was a slight difference in the prevalence rate of color blindness, and allergic diseases for male students ; and color blindness, hearing disturbance and allergic disease for female students. For those items, however, it is too little to say that there is a significant difference and accordingly it is assumed to be a problem of the measuring process. Sixth, the result of analysis on the sample physical examination and the total physical examination of the year 1999 shows as follows: For male students in the 3rd year of middle school, a slight difference appeared to those students in 11 items including eye problems and eye disease, otitis media, tonsillar hypertrophy, spinal shape, respiratory urinary allergic disease and other abnormal diseases(p<0.05). Particularly, the prevalence rate between students with and without disease was shown to be two times more in the following: eye problems, otitis media, tonsill hypertrophy, allergic diseases, etc. For female students in the 3rd year, prevalence rate showed little difference in 14 items(p<0.05). For items including eye problem, otitis media, tonsill hypertrophy, allergic disease, etc. it was shown that the rate was two times more between students with and without diseases. Physical examinations under the current school system are not producing any fundamental results for the health of the students. Methods and results are not trustworthy. Accordingly, a drastic overhaul of the current practices is needed in frequency, methods and items on the list in order to promote the health of the students. Cost-benefit studies as well as political considerations to ensure the development of efficient methods for physical examination are urgently needed at this moment.

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A Case Study about Counting Uncertainty of Radioactive Iodine (131I) in Public Waters by Using Gamma Spectrometry (감마분광분석을 이용한 환경 중 방사성요오드(131I)의 측정 불확도에 관한 사례 연구)

  • Cho, Yoonhae;Seol, Bitna;Min, Kyoung Ok;Kim, Wan Suk;Lee, Junbae;Lee, Soohyung
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.1
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    • pp.42-46
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    • 2016
  • The radioactive iodine ($^{131}I$) presents in the environment through the excrete process of nuclear medicine patients. In the detecting of low level of $^{131}I$ in the public water, the counting uncertainty has an effect on the accuracy and reliability of detecting $^{131}I$ radioactivity concentration. In this study, the contribution of sample amount, radioactivity concentration and counting time to the uncertainty was investigated in the case of public water sample. Sampling points are public water and the effluents of a sewage treatment plant at Sapkyocheon stream, Geumgang river. In each point, 1, 10 and 20 L of liquid samples were collected and prepared by evaporation method. The HPGe (High Purity Germanium) detector was used to detect and analyze emitted gamma-ray from samples. The radioactivity concentration of $^{131}I$ were in the range of 0.03 to 1.8 Bq/L. The comparison of the counting uncertainty of the sample amount, 1 L sample is unable to verify the existence of the $^{131}I$ under 0.5 Bq/L radioactivity concentration. Considering the short half-life of $^{131}I$ (8.03 days), a method for measuring 1 L sample was used. However comparing the detecting and preparing time of 1, 10 L respectively, detecting 10 L sample would be an appropriate method to distinguish $^{131}I$ concentration in the public water.

Characteristics of Variation of Suspended Matters in the Cheju Coastal Area of Korea (제주 연안해역의 부유물질 변화특성)

  • Youn, Jeung-Su;Pyen, Choong-Kyu
    • Journal of Aquaculture
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    • v.5 no.1
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    • pp.93-108
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    • 1992
  • This study was conducted to understand the variation of suspended matters in coastal waters of Cheju Island. Water sampling was carried out at 22 stations along the coast of this island from March 1988 to November 1989. Analyzed and/or observed items were water temperature, salinity, total solids (TS), total dissolved solids (TDS), volatile suspended solids (VSS), and fixed suspended solids (FSS). Inter-relationships between wind velocity, precipitation and total suspended solids (TSS) were also investigated. More windy days prevail in winter season (December, January and February) in Cheju Island. Thirty-six points seven percent of total windy days of a year appeared in this season. The rate of windy days in spring was $27.3\%$ and those in summer and fall were $17.9{\%}$ each. From February to July, the heaviest precipitation was observed in the southeastern area and that from August to January was observed in the eastern part of this island. TS and TDS were firmly related with the fluctuation of salinity. Therefore, there were higher in spring and lower in summer. The highest TSS (7.73 $mg/{\ell}$) was observed in February and was the lowest (4.73 $mg/{\ell}$) in September. Annual mean value of TSS was 6.3$mg/{\ell}$. The highest VSS (2.03 $mg/{\ell}$) was observed in July and lowest (1.42 $mg/{\ell}$) in September. The percentage of VSS per 755 was $30.6{\%}$ in average that was not much higher level compared to the other polluted areas. This value became higher in summer (av. $34.17{\%}$) and lower in winter (av. $24.2{\%}$). Fluctuation of TSS was mainly related with the freshwate. discharge, tidal action, and re-suspension of bottom sediments by the wind waves. Therefore, TSS concentration was low in summer and hish in winter.

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The Effects of Cognitive Bias on Entrepreneurial Opportunity Evaluations through Perceived Risks in Entrepreneurial Self-Efficacy (창업가의 인지편향이 지각된 위험과 조절된 창업효능감에 따라 창업기회평가에 미치는 영향)

  • Kim, Daeyop;Park, Jaehwan
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.1
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    • pp.95-112
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    • 2020
  • This paper is to investigate how cognitive bias of college students and entrepreneurs relates to perceived risks and entrepreneurial opportunities that represent uncertainty, and how various cognitive bias and entrepreneurial efficacy In the same way. The purpose of this study is to find improvement points of entrepreneurship education for college students and to suggest problems and improvement possibilities in the decision making process of current entrepreneurs. This empirical study is a necessary to improve the decision-making of individuals who want to start a business at the time when various attempts are made to activate the start-up business and increase the sustainability of the existing SME management. And understanding of the difference in opportunity evaluation, and suggests that it is necessary to provide good opportunities together with the upbringing of entrepreneurs. In order to achieve the purpose of the study, questionnaires were conducted for college students and entrepreneurs. A total of 363 questionnaire data were obtained and demonstrated through structural equation modeling. This study confirms that there is some relationship between perceived risk and cognitive bias. Overconfidence and control illusions among cognitive bias have a significant relationship between perceived risk and wealth. Especially, it is confirmed that control illusion of college students has a significant relationship with perceived risk. Second, cognitive bias demonstrated some significant relationship with opportunity evaluation. Although we did not find evidence that excess self-confidence is related to opportunity evaluation, we have verified that control illusions and current status bias are related to opportunity evaluation. Control illusions were significant in both college students and entrepreneurs. Third, perceived risk has a negative relationship with opportunity evaluation. All students, regardless of whether they are college students or entrepreneurs, judge opportunities positively if they perceive low risk. Fourth, it can be seen from the college students 'group that entrepreneurial efficacy has a moderating effect between perceived risk and opportunity evaluation, but no significant results were found in the entrepreneurs' group. Fifth, the college students and entrepreneurs have different cognitive bias, and they have proved that there is a different relationship between entrepreneurial opportunity evaluation and perceived risk. On the whole, there are various cognitive biases that are caused by time pressure or stress on college students and entrepreneurs who have to make judgments in uncertain opportunities, and in this respect, they can improve their judgment in the future. At the same time, university students can have a positive view of new opportunities based on high entrepreneurial efficacy, but if they fully understand the intrinsic risks of entrepreneurship through entrepreneurial education and fully understand the cognitive bias present in direct entrepreneurial experience, You will get a better opportunity assessment. This study has limitations in that it is based on the fact that university students and entrepreneurs are integrated, and that the survey respondents are selected by the limited random sampling method. It is necessary to conduct more systematic research based on more faithful data in the absence of the accumulation of entrepreneurial research data. Second, the translation tools used in the previous studies were translated and the meaning of the measurement tools might not be conveyed due to language differences. Therefore, it is necessary to construct a more precise scale for the accuracy of the study. Finally, complementary research should be done to identify what competitive opportunities are and what opportunities are appropriate for entrepreneurs.