• Title/Summary/Keyword: Sensitivity Analysis

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DEVELOPMENT OF STATEWIDE TRUCK TRAFFIC FORECASTING METHOD BY USING LIMITED O-D SURVEY DATA (한정된 O-D조사자료를 이용한 주 전체의 트럭교통예측방법 개발)

  • 박만배
    • Proceedings of the KOR-KST Conference
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    • 1995.02a
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    • pp.101-113
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    • 1995
  • The objective of this research is to test the feasibility of developing a statewide truck traffic forecasting methodology for Wisconsin by using Origin-Destination surveys, traffic counts, classification counts, and other data that are routinely collected by the Wisconsin Department of Transportation (WisDOT). Development of a feasible model will permit estimation of future truck traffic for every major link in the network. This will provide the basis for improved estimation of future pavement deterioration. Pavement damage rises exponentially as axle weight increases, and trucks are responsible for most of the traffic-induced damage to pavement. Consequently, forecasts of truck traffic are critical to pavement management systems. The pavement Management Decision Supporting System (PMDSS) prepared by WisDOT in May 1990 combines pavement inventory and performance data with a knowledge base consisting of rules for evaluation, problem identification and rehabilitation recommendation. Without a r.easonable truck traffic forecasting methodology, PMDSS is not able to project pavement performance trends in order to make assessment and recommendations in the future years. However, none of WisDOT's existing forecasting methodologies has been designed specifically for predicting truck movements on a statewide highway network. For this research, the Origin-Destination survey data avaiiable from WisDOT, including two stateline areas, one county, and five cities, are analyzed and the zone-to'||'&'||'not;zone truck trip tables are developed. The resulting Origin-Destination Trip Length Frequency (00 TLF) distributions by trip type are applied to the Gravity Model (GM) for comparison with comparable TLFs from the GM. The gravity model is calibrated to obtain friction factor curves for the three trip types, Internal-Internal (I-I), Internal-External (I-E), and External-External (E-E). ~oth "macro-scale" calibration and "micro-scale" calibration are performed. The comparison of the statewide GM TLF with the 00 TLF for the macro-scale calibration does not provide suitable results because the available 00 survey data do not represent an unbiased sample of statewide truck trips. For the "micro-scale" calibration, "partial" GM trip tables that correspond to the 00 survey trip tables are extracted from the full statewide GM trip table. These "partial" GM trip tables are then merged and a partial GM TLF is created. The GM friction factor curves are adjusted until the partial GM TLF matches the 00 TLF. Three friction factor curves, one for each trip type, resulting from the micro-scale calibration produce a reasonable GM truck trip model. A key methodological issue for GM. calibration involves the use of multiple friction factor curves versus a single friction factor curve for each trip type in order to estimate truck trips with reasonable accuracy. A single friction factor curve for each of the three trip types was found to reproduce the 00 TLFs from the calibration data base. Given the very limited trip generation data available for this research, additional refinement of the gravity model using multiple mction factor curves for each trip type was not warranted. In the traditional urban transportation planning studies, the zonal trip productions and attractions and region-wide OD TLFs are available. However, for this research, the information available for the development .of the GM model is limited to Ground Counts (GC) and a limited set ofOD TLFs. The GM is calibrated using the limited OD data, but the OD data are not adequate to obtain good estimates of truck trip productions and attractions .. Consequently, zonal productions and attractions are estimated using zonal population as a first approximation. Then, Selected Link based (SELINK) analyses are used to adjust the productions and attractions and possibly recalibrate the GM. The SELINK adjustment process involves identifying the origins and destinations of all truck trips that are assigned to a specified "selected link" as the result of a standard traffic assignment. A link adjustment factor is computed as the ratio of the actual volume for the link (ground count) to the total assigned volume. This link adjustment factor is then applied to all of the origin and destination zones of the trips using that "selected link". Selected link based analyses are conducted by using both 16 selected links and 32 selected links. The result of SELINK analysis by u~ing 32 selected links provides the least %RMSE in the screenline volume analysis. In addition, the stability of the GM truck estimating model is preserved by using 32 selected links with three SELINK adjustments, that is, the GM remains calibrated despite substantial changes in the input productions and attractions. The coverage of zones provided by 32 selected links is satisfactory. Increasing the number of repetitions beyond four is not reasonable because the stability of GM model in reproducing the OD TLF reaches its limits. The total volume of truck traffic captured by 32 selected links is 107% of total trip productions. But more importantly, ~ELINK adjustment factors for all of the zones can be computed. Evaluation of the travel demand model resulting from the SELINK adjustments is conducted by using screenline volume analysis, functional class and route specific volume analysis, area specific volume analysis, production and attraction analysis, and Vehicle Miles of Travel (VMT) analysis. Screenline volume analysis by using four screenlines with 28 check points are used for evaluation of the adequacy of the overall model. The total trucks crossing the screenlines are compared to the ground count totals. L V/GC ratios of 0.958 by using 32 selected links and 1.001 by using 16 selected links are obtained. The %RM:SE for the four screenlines is inversely proportional to the average ground count totals by screenline .. The magnitude of %RM:SE for the four screenlines resulting from the fourth and last GM run by using 32 and 16 selected links is 22% and 31 % respectively. These results are similar to the overall %RMSE achieved for the 32 and 16 selected links themselves of 19% and 33% respectively. This implies that the SELINICanalysis results are reasonable for all sections of the state.Functional class and route specific volume analysis is possible by using the available 154 classification count check points. The truck traffic crossing the Interstate highways (ISH) with 37 check points, the US highways (USH) with 50 check points, and the State highways (STH) with 67 check points is compared to the actual ground count totals. The magnitude of the overall link volume to ground count ratio by route does not provide any specific pattern of over or underestimate. However, the %R11SE for the ISH shows the least value while that for the STH shows the largest value. This pattern is consistent with the screenline analysis and the overall relationship between %RMSE and ground count volume groups. Area specific volume analysis provides another broad statewide measure of the performance of the overall model. The truck traffic in the North area with 26 check points, the West area with 36 check points, the East area with 29 check points, and the South area with 64 check points are compared to the actual ground count totals. The four areas show similar results. No specific patterns in the L V/GC ratio by area are found. In addition, the %RMSE is computed for each of the four areas. The %RMSEs for the North, West, East, and South areas are 92%, 49%, 27%, and 35% respectively, whereas, the average ground counts are 481, 1383, 1532, and 3154 respectively. As for the screenline and volume range analyses, the %RMSE is inversely related to average link volume. 'The SELINK adjustments of productions and attractions resulted in a very substantial reduction in the total in-state zonal productions and attractions. The initial in-state zonal trip generation model can now be revised with a new trip production's trip rate (total adjusted productions/total population) and a new trip attraction's trip rate. Revised zonal production and attraction adjustment factors can then be developed that only reflect the impact of the SELINK adjustments that cause mcreases or , decreases from the revised zonal estimate of productions and attractions. Analysis of the revised production adjustment factors is conducted by plotting the factors on the state map. The east area of the state including the counties of Brown, Outagamie, Shawano, Wmnebago, Fond du Lac, Marathon shows comparatively large values of the revised adjustment factors. Overall, both small and large values of the revised adjustment factors are scattered around Wisconsin. This suggests that more independent variables beyond just 226; population are needed for the development of the heavy truck trip generation model. More independent variables including zonal employment data (office employees and manufacturing employees) by industry type, zonal private trucks 226; owned and zonal income data which are not available currently should be considered. A plot of frequency distribution of the in-state zones as a function of the revised production and attraction adjustment factors shows the overall " adjustment resulting from the SELINK analysis process. Overall, the revised SELINK adjustments show that the productions for many zones are reduced by, a factor of 0.5 to 0.8 while the productions for ~ relatively few zones are increased by factors from 1.1 to 4 with most of the factors in the 3.0 range. No obvious explanation for the frequency distribution could be found. The revised SELINK adjustments overall appear to be reasonable. The heavy truck VMT analysis is conducted by comparing the 1990 heavy truck VMT that is forecasted by the GM truck forecasting model, 2.975 billions, with the WisDOT computed data. This gives an estimate that is 18.3% less than the WisDOT computation of 3.642 billions of VMT. The WisDOT estimates are based on the sampling the link volumes for USH, 8TH, and CTH. This implies potential error in sampling the average link volume. The WisDOT estimate of heavy truck VMT cannot be tabulated by the three trip types, I-I, I-E ('||'&'||'pound;-I), and E-E. In contrast, the GM forecasting model shows that the proportion ofE-E VMT out of total VMT is 21.24%. In addition, tabulation of heavy truck VMT by route functional class shows that the proportion of truck traffic traversing the freeways and expressways is 76.5%. Only 14.1% of total freeway truck traffic is I-I trips, while 80% of total collector truck traffic is I-I trips. This implies that freeways are traversed mainly by I-E and E-E truck traffic while collectors are used mainly by I-I truck traffic. Other tabulations such as average heavy truck speed by trip type, average travel distance by trip type and the VMT distribution by trip type, route functional class and travel speed are useful information for highway planners to understand the characteristics of statewide heavy truck trip patternS. Heavy truck volumes for the target year 2010 are forecasted by using the GM truck forecasting model. Four scenarios are used. Fo~ better forecasting, ground count- based segment adjustment factors are developed and applied. ISH 90 '||'&'||' 94 and USH 41 are used as example routes. The forecasting results by using the ground count-based segment adjustment factors are satisfactory for long range planning purposes, but additional ground counts would be useful for USH 41. Sensitivity analysis provides estimates of the impacts of the alternative growth rates including information about changes in the trip types using key routes. The network'||'&'||'not;based GMcan easily model scenarios with different rates of growth in rural versus . . urban areas, small versus large cities, and in-state zones versus external stations. cities, and in-state zones versus external stations.

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Machine learning-based corporate default risk prediction model verification and policy recommendation: Focusing on improvement through stacking ensemble model (머신러닝 기반 기업부도위험 예측모델 검증 및 정책적 제언: 스태킹 앙상블 모델을 통한 개선을 중심으로)

  • Eom, Haneul;Kim, Jaeseong;Choi, Sangok
    • Journal of Intelligence and Information Systems
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    • v.26 no.2
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    • pp.105-129
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    • 2020
  • This study uses corporate data from 2012 to 2018 when K-IFRS was applied in earnest to predict default risks. The data used in the analysis totaled 10,545 rows, consisting of 160 columns including 38 in the statement of financial position, 26 in the statement of comprehensive income, 11 in the statement of cash flows, and 76 in the index of financial ratios. Unlike most previous prior studies used the default event as the basis for learning about default risk, this study calculated default risk using the market capitalization and stock price volatility of each company based on the Merton model. Through this, it was able to solve the problem of data imbalance due to the scarcity of default events, which had been pointed out as the limitation of the existing methodology, and the problem of reflecting the difference in default risk that exists within ordinary companies. Because learning was conducted only by using corporate information available to unlisted companies, default risks of unlisted companies without stock price information can be appropriately derived. Through this, it can provide stable default risk assessment services to unlisted companies that are difficult to determine proper default risk with traditional credit rating models such as small and medium-sized companies and startups. Although there has been an active study of predicting corporate default risks using machine learning recently, model bias issues exist because most studies are making predictions based on a single model. Stable and reliable valuation methodology is required for the calculation of default risk, given that the entity's default risk information is very widely utilized in the market and the sensitivity to the difference in default risk is high. Also, Strict standards are also required for methods of calculation. The credit rating method stipulated by the Financial Services Commission in the Financial Investment Regulations calls for the preparation of evaluation methods, including verification of the adequacy of evaluation methods, in consideration of past statistical data and experiences on credit ratings and changes in future market conditions. This study allowed the reduction of individual models' bias by utilizing stacking ensemble techniques that synthesize various machine learning models. This allows us to capture complex nonlinear relationships between default risk and various corporate information and maximize the advantages of machine learning-based default risk prediction models that take less time to calculate. To calculate forecasts by sub model to be used as input data for the Stacking Ensemble model, training data were divided into seven pieces, and sub-models were trained in a divided set to produce forecasts. To compare the predictive power of the Stacking Ensemble model, Random Forest, MLP, and CNN models were trained with full training data, then the predictive power of each model was verified on the test set. The analysis showed that the Stacking Ensemble model exceeded the predictive power of the Random Forest model, which had the best performance on a single model. Next, to check for statistically significant differences between the Stacking Ensemble model and the forecasts for each individual model, the Pair between the Stacking Ensemble model and each individual model was constructed. Because the results of the Shapiro-wilk normality test also showed that all Pair did not follow normality, Using the nonparametric method wilcoxon rank sum test, we checked whether the two model forecasts that make up the Pair showed statistically significant differences. The analysis showed that the forecasts of the Staging Ensemble model showed statistically significant differences from those of the MLP model and CNN model. In addition, this study can provide a methodology that allows existing credit rating agencies to apply machine learning-based bankruptcy risk prediction methodologies, given that traditional credit rating models can also be reflected as sub-models to calculate the final default probability. Also, the Stacking Ensemble techniques proposed in this study can help design to meet the requirements of the Financial Investment Business Regulations through the combination of various sub-models. We hope that this research will be used as a resource to increase practical use by overcoming and improving the limitations of existing machine learning-based models.

Analysis of Antibodies Cross-reactive with Pressate Extract Antigen from Mycobacterium tuberculosis and Other 3 Species Mycobacteria in Sera of Patients with Pulmonary Tuberculosis (결핵균 및 기타 3종 Mycobacteria의 파쇄추출항원과 교차반응하는 폐결핵환자의 항체분석)

  • Cho, Myung-Je;Hwang, Eung-Soo;Kook, Yoon-Hoh;Kim, Ik-Sang;Lee, Seoung-Hoon;Cha, Chang-Yong;Shim, Young-Soo;Han, Yong-Chol;Bae, Gill-Han;Kim, Sang-Jae
    • The Journal of the Korean Society for Microbiology
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    • v.20 no.1
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    • pp.79-89
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    • 1985
  • It is important to discriminate between tuberculosis and tuberculosis-like disease by Mycobacteria other than tuberculosis in the serodiagnosis of tuberculosis. But because common antigens share among Mycobacteria, their antigenicities to human are similar. Therefore degree of cross-reactivity of antibody in the sera of patients with tuberculosis between M. tuberculosis and Mycobacteria other than tuberculosis should be checked to increase the specificity in the serodiagnosis of tuberculosis. The activity levels of IgG antibody in the sera of 106 patients confirmed as active pulmonary tuberculosis and 30 normal healthy control person to the pressate extract antigen (TE, BE, AE, and FE antigen) from M. tuberculosis, M. bovis, M. avium, and M. fortuitum were measured by enzyme-linked immunosorbent assay and the crossreactivity of IgG antibody with mycobacterial species was analysed. The results were as follows; 1. The activity level(O.D. at 492nm) of IgG to TE antigen in sera of patients with pulmonary tuberculosis was $0.228{\pm}0.167$ in minimal tuberculosis; moderately advanced, $0.556{\pm}0.616$; far advanced, $1.116{\pm}0.651$ and $0.315{\pm}0.245$ in miliary tuberculosis. 2. The activity level (O.D. at 492nm) of IgG to BE antigen in sera of patients with pulmonary tuberculosis was $0.190{\pm}0.162$ in minimal tuberculosis; moderately advanced, $0.337{\pm}0.361$; far advanced, $0.713[\pm}0.460$ and $0.204{\pm}0.162$ in miliary tuberculosis. 3. The activity level (O.D. at 492nm) of IgG to AE antigen in sera of patients with pulmonary tuberculosis was $0.165{\pm}0.114$ in minimal tuberculosis; moderately advanced, $0.392{\pm}0.494$; far advenced, $0.751{\pm}0.512$ and $0.233{\pm}0.191$ in miliary tuberculosis. 4. The activity level (O.D. at 492nm) of IgG to FE antigen in sera of patients with pulmonary tuberculosis was $0.280{\pm}0.227$ in minimal tuberculosis; moderately advanced, $0.460{\pm}0.564$ ; far advanced, $0.845{\pm}0.573$ and $0.257{\pm}0.103$ in miliary tuberculosis. 5. The activity level (O.D. at 492nm) of IgG in sera of healthy control person was $0.126{\pm}0.084$ to TE antigen. $0.105{\pm}0.041$ to BE antigen, $0.103{\pm}0.052$ to AE antigen, and $0.095{\pm}0.061$ to FE antigen. 6. Degree of correlation(r) in activity level of IgG between TE antigen and BE antigen was 0.905 ; between TE antigen and AE antigen, 0.760; between TE antigen and FE antigen, 0.790, and between AE antigen and FE antigen, 0.945. 7. As O.D. above 0.200 was determined positive for the serodiagnosis of pulmonary tuberculosis, the sensitivity and specificity in ELISA using TE antigen were 80% and 87% respectively, whereas in the case of using BE antigen, 66% and 100%; in the case of using AE antigen, 62% and 100%, and in the case of using FE antigen, 72% and 93%, respecitively.

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Design Anamorphic Lens Thermal Optical System that Focal Length Ratio is 3:1 (초점거리 비가 3:1인 아나모픽 렌즈 열상 광학계 설계)

  • Kim, Se-Jin;Ko, Jung-Hui;Lim, Hyeon-Seon
    • Journal of Korean Ophthalmic Optics Society
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    • v.16 no.4
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    • pp.409-415
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    • 2011
  • Purpose: To design applied anamorphic lens that focal length ratio is 3:1 optical system to improve detecting distance. Methods: We defined a boundary condition as $50^{\circ}{\sim}60^{\circ}$ for viewing angle, horizontal direction 36mm, vertical direction 12 mm for focal length, f-number 4, $15{\mu}m{\times}15{\mu}m$ for pixel size and limit resolution 25% in 33l p/mm. Si, ZnS and ZnSe as a materials were used and 4.8 ${\mu}m$, 4.2 ${\mu}m$, 3.7 ${\mu}m$ as a wavelength were set. optical performance with detection distance, narcissus and athermalization in designed camera were analyzed. Results: F-number 4, y direction 12 mm and x direction 36 mm for focal length of the thermal optical system were satisfied. Total length of the system was 76 mm so that an overall volume of the system was reduced. Astigmatism and spherical aberration was within ${\pm}$0.10 which was less than 2 pixel size. Distortion was within 10% so there was no matter to use as a thermal optical camera. MTF performance for the system was over 25% from 33l p/mm to full field so it was satisfied with the boundary condition. Designed optical system was able to detect up to 2.9 km and reduce a diffused image by decreasing a narcissus value from all surfaces except the 4th surface. From sensitivity analysis, MTF resolution was increased on changing temperature with the 5th lens which was assumed as compensation. Conclusions: Designed optical system which used anamorphic lens was satisfied with boundary condition. an increasing resolution with temperature, longer detecting distance and decreasing of narcissus were verified.

A VALIDITY STUDY OF PARENT BEHAVIORAL RATING SCALES AS DIAGNOSTIC TOOLS OF ATTENTION DEFICIT/HYPERACTIVITY DISORDER (주의력결핍/과잉운동장애(ADHD) 아동의 진단도구로서 부모용 행동 평가지의 타당도 연구 - 한국아동인성검사와 아동 ${\cdot}$ 청소년 행동평가척도를 중심으로 -)

  • Kim, Ji-Hae;So, Yoo-Kyung;Jung, Yoo-Sook;Lee, Im-Soon;Hong, Sung-Do
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.11 no.2
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    • pp.282-289
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    • 2000
  • This study was designed to examine the validity of HPR subscale in Korean Personality Inventory for Children(KPI-C) and Attention Problems subscale in Korean Child Behavior Checklist(K-CBCL) as diagnostic tool for Attention-Deficit/Hyperactivity Disorder(ADHD). Nineteen ADHD-1 type, twenty-three ADHD-H type, sixteen Neurosis, and fifteen normal children with the age from 6 to12 were selected based on DSM-IV, and their responses of the KPI-C and CBCL were analyzed. Omnibus F-test results showed that there were significant differences in the F scores of HPR and Attention Problems T scores(p<.05). But in Posthoc analysis, the HPR and AP scores in three clinical groups were significantly higher than in normal group, but there was no group difference among three clinical groups(p<.05). These results shows that HPR subscale and Attention Problems subscale may be useful tools for screening clinical groups(vs normal group) but there was a limit to the clinical validity of two subscales as diagnostic tools for the subtypes of ADHD.

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The Correlation between Sensory Process Type and Interpersonal Problems, Adult Attachment on University Students (대학생의 감각처리 유형과 대인관계문제 및 성인애착의 관계)

  • Yoon, Su-Jeong;Lee, Chun-Yeop;Kim, Hee-Jung;Jung, Hye-Rim
    • The Journal of Korean society of community based occupational therapy
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    • v.7 no.2
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    • pp.9-18
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    • 2017
  • Objective : This study was to find out the level of sensory process type, adult attachment and interpersonal problems on university students and then to investigate the correlation. Methods : For this study, 169 students who don't know about the evaluation tool in university students of K area in Korea were participated. To execute evaluation, Adolescents/Adults Sensory Profile (AASP) was used for the sensory process type, Short Form of the Korean Inventory of Interpersonal Problems Circumplex Scale (KIIP-SC) was used for interpersonal problems, and Experiences in Close Relationships Scale-Revised (ECR-R) was used for the adult attachment. The correlation between sensory process type and interpersonal problems, adult attachment was analyzed by using pearson correlation analysis. Results : Sensory process type of university students appeared that sensory seeking was lower than general people, and the rest of items showed similar results with general people. For interpersonal problems, there was a lot of difficulty in self-sacrificing and overly accommodating, whereas there was a little difficulty in vindictive and domineering / controlling. For adult attachment, attachment avoiding was more stable than attachment anxiety. Also, low registration and sensory sensitivity all showed positive correlation with interpersonal problems and adult attachment. Among interpersonal problems, self-sacrificing and intrusive showed positive correlation with sensory seeking whereas cold, socially inhibited, nonassertive, and overly accommodating showed positive correlation with sensory avoiding. Thus, sensory seeking and sensory avoiding showed different results (p<.05). Conclusion : In occupational therapy clinic, not only the disabled but non-disabled people that experience issue of interpersonal problems and attachment could be helped with managing high quality social activity if they execute intervention according to sensory process type.

The Effect of Characteristics of Venture Business Founders and Management Strategy on Business Performance (벤처기업 창업가의 특성과 경영전략이 경영성과에 미치는 영향)

  • Han, Kyudong
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.6
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    • pp.29-43
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    • 2019
  • This paper empirically analyzed the relationship between the characteristics of venture business founders and management performance, setting the management strategy as a parameter to provide a suggestion for the survival and development of venture companies that play an important role in the national economy and job creation. Previous studies in Korea have analyzed the relationship between the characteristics of business founders, management strategies and management performance in a single dimension. This paper, however, explained the business performance of a company from a multi-dimensional perspective while setting the characteristics of business founders as independent variables and setting the business strategy of the enterprise as a parameter. The first result of the analysis shows that the characteristics of venture business founders have a positive effect on business performance. In particular, among the characteristics of venture business founders, a progressive spirit has had the greatest impact on business performance. On the other hand, the influence of risk sensitivity was very weak. Second, the characteristics of venture business founders were found to have a positive effect on business strategy. In particular, innovation was an important variable that affected the technological innovation differentiation strategy, and a progressive spirit was the most influential factor in the marketing differentiation strategy. Third, management strategies of venture firms were found to have a positive effect on business performance. In particular, the technology innovation differentiation strategy has a greater impact on business performance than the marketing differentiation strategy. Fourth, it was revealed that management strategy partially has a mediated effect on the relationship between the characteristics of venture business founders and management performance. In other words, it was found that the characteristics of the founders have a direct impact on business performance but if it is linked to management strategy it has an indirect effect on business performance. The results of this study show that business performance improves when venture business founders' personal characteristics and the firms' management strategy are combined.

Increases in Doxorubicin Sensitivity and Radioiodide Uptake by Transfecting shMDR and Sodium/Iodide Symporter Gene in Cancer Cells Expressing Multidrug Resistance (다약제내성 암세포에서 shMDR과 Sodium/Iodide Symporter 유전자의 이입에 의한 Doxorubicin 감수성과 방사성옥소 섭취의 증가)

  • Ahn, Sohn-Joo;Lee, Yong-Jin;Lee, You-La;Choi, Chang-Ik;Lee, Sang-Woo;Yoo, Jeong-Soo;Ahn, Byeong-Cheol;Lee, In-Kyu;Lee, Jae-Tae
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.3
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    • pp.209-217
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    • 2007
  • Purpose: Multidrug resistance (MDR) of the cancer cells related to mdr1 gene expression can be effectively treated by selective short hairpin RNA for mdr1 gene (shMDR). Sodium/iodide symporter (NIS) gene is well known to have both reporter and therapeutic gene characteristics. We have co-transfected both shMDR and NIS gene into colon cancer cells (HCT15 cell) expressing MDR and Tc-99m sestamibi and I-125 uptake were measured. In addition, cytotoxic effects of doxorubicin and I-131 therapy were also assessed after transfection. Material and Methods: At first, shMDR was transfected with liposome reagent into human embryonic kidney cells (HEK293) and HCT cells. shMDR transfection was confirmed by RT-PCR and western blot analysis. Adenovirus expressing NIS (Ad-NIS) gene and shMDR (Ad-shMDR) were co-transfected with Ad-NIS into HCT15 cells. Forty-eight hours after infection, inhibition of P-gycoprotein (Pgp) function by shMDR was analyzed by a change of Tc-99m sestamibi uptake and doxorubicin cytotoxicity, and functional activity of induced NIS gene expression was assessed with I-125 uptake assay. Results: In HEK293 cells transfected with shMDR, mdr1 mRNA and Pgp protein expressions were down regulated. HCT15 cells infected with 20 MOI of Ad-NIS was higher NIS protein expression than control cells. After transfection of 300 MOI of Ad-shMDR either with or without 10 MOI of Ad-NIS, uptake of Tc-99m sestamibi increased up to 1.5-fold than control cells. HCT15 cells infected with 10 MOI of Ad-NIS showed approximately 25-fold higher I-125 uptake than control cells. Cotransfection of Ad-shMDR and Ad-NIS resulted in enhanced cytotoxic by doxorubicin in HCT15 cells. I-131 treatment on HCT15 cells infected with 20 MOI of Ad-NIS revealed increased cytotoxic effect. Conclusion: Suppression of mdr1 gene expression, retention of Tc-99m sestamibi, enhanced doxorubicin cytotoxicity and increases in I-125 uptake were achieved in MDR expressing cancer cell by co-transfection of shMDR and NIS gene. Dual therapy with doxorubicin and radioiodine after cotransfection shMDR and NIS gene can be used to overcome MDR.

Improving Diagnostic Accuracy for Malignant Nodes and N Staging in Non-Small Cell Lung Cancer Using CT-Corrected FDG-PET (비소세포폐암에서 CT-보정 양전자단층촬영술을 이용한 악성 림프절 평가 및 N 병기 결정 성적 향상)

  • Lee, Eun-Jeong;Choi, Joon-Young;Lee, Kyung-Soo;Chung, Hyun-Woo;Lee, Su-Jin;Cho, Young-Seok;Choi, Yong;Choe, Yearn-Seong;Lee, Kyung-Han;Kwon, O-Jung;Shim, Young-Mog;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.4
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    • pp.231-238
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    • 2005
  • Purpose: We investigated prospectively whether the interpretation considering the patterns of FDG uptake and the findings of unenhanced CT for attenuation correction can improve the diagnostic accuracy for assessing malignant lymph node (LN) and N stage in non-small cell lung cancor (NSCLC) using CT-corrected FDG-PET (PET/CT). Materials & Methods: Subjects were 91 NSCLC patients (M/F 62/29, age: $60{\pm}9$ yr) who underwent PET/CT before in dissection. We evaluated the maximum SUV (maxSUV), patterns of FDG uptake, short axis diameter, and calcification of LN showing abnormally increased FDG uptake. Then we investigated criteria improving the diagnostic accuracy and correlated results with postoperative pathology. In step 1, in was classified as benign or malignant based on maxSUV only. In step 2, LN was regarded as benign if it had lower maxSUV than the cut-off value of step 1 or it had calcification irrespective of its maxSUV. In step 3, LN regarded as malignant in step 2 was classified as benign if they had indiscrete margin of FDG uptake. Results: Among 432 LN groups surgically resected (28 malignant, 404 benign), 71 showed abnormally increased FDG uptake. We determined the cut-off as maxSUV=3.5 using ROC curve analysis. The sensitivity, specificity, and accuracy for assessing malignant LN were 64.3%, 86.9%, 85.4% in step 1, 64.3%, 95.0%, 93.1% in step 2, and 57.1%, 98.0%, 95.4% in step3, respectively. The accuracy for assessing N stage was 64.8% in step 1, 80.2% in step 2, and 85.7% in step 3. Conclusion: interpreting PET/CT, consideration of calcification and shape of the FDG uptake margin along with maxSUV can improve the diagnostic accuracy for assessing malignant involvement and N stage of hilar and mediastinal LNs in NSCLC.

Environmental Impact Assessment of Rapeseed Cultivation by Life Cycle Assessment (전과정평가를 이용한 유채재배의 환경영향 평가)

  • Hong, Seung-Gil;Nam, Jae-Jak;Shin, Joung-Du;Ok, Yong-Sik;Choi, Bong-Su;Yang, Jae-E.;Kim, Jeong-Gyu;Lee, Sung-Eun
    • Korean Journal of Environmental Agriculture
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    • v.30 no.1
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    • pp.24-30
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    • 2011
  • BACKGROUND: High input to the arable land is contributed to increasing productivity with causing the global environmental problems at the same time. Rapeseed cultivation has been forced to reassess its positive point for utilization of winter fallow field. The Objective of this study was performed to assess the environmental impact of rapeseed cultivation with double-cropping system in paddy rice on Yeonggwang district using life cycle assessment technique. METHODS AND RESULTS: For assessing each stage of rapeseed cultivation, it was collected raw data for input materials as fertilizer and pesticide and energy consumption rate by analyzing the type of agricultural machinery and working hours by 1 ton rapeseed as functional unit. Environmental impacts were evaluated by using Eco-indicator 95 method for 8 impact categories. It was estimated that 216 kg $CO_2$-eq. for greenhouse gas, 3.98E-05 kg CFC-11-eq. for ozone lazer depletion, 1.78 kg SO2-eq. for acidification, 0.28 kg $PO_4$-eq. for eutrophication, 5.23E-03 kg Pb-eq. for heavy metals, 2.51E-05 kg B(a)p-eq. for carcinogens, 1.24 kg SPM-eq. for smog and 6,460 MJ LHV for energy resource are potentially emitted to produce 1 ton rapeseed during its whole cultivation period, respectively. It was considered that 90% of these potential came from chemical fertilizer. For the sensitivity analysis, by increasing the productivity of rapeseed by 1 ton per ha, potential environmental loading was reduced at 22%. CONCLUSION(s): Fertilization affected most dominantly to the environmental burden, originated from the preuse stage, i.e. fertilizer manufacturing and transporting. It should be included and assessed an indirect emission, which is not directly emitted from agricultural activities. Recycling resource in agriculture with reducing chemical fertilizer and breeding the high productive variety might be contribute to reduce the environmental loading for the rapeseed cultivation.