• Title/Summary/Keyword: Estimate Criteria

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Disaggregate Demand Forecasting and Estimation of the Optimal Price for VTIS (부가교통정보시스템(VTIS) 이용수요예측 및 적정이용료 산정에 관한 연구)

  • 정헌영;진재업;손태민
    • Journal of Korean Society of Transportation
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    • v.20 no.4
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    • pp.27-38
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    • 2002
  • VTIS(Value-added Traffic Information System), among the sub-systems of ATIS, is an Advanced Traffic System which innovates efficiency and safety. And this system, having marketability and publicness, is very important. Moreover, This system offers definite traffic information according to the demand of specified users. And it is expected to produce additional spread effects because of high participation rate of private sector. However, the VTIS service media are varied and there are varied optimal Prices and payment methods according to each medium. Because of that, there needs the study on these problems or optimal criteria. But because existing studies were devoted to estimate the optimal route, the study toward the optimal price which was considered part of user and service use demand do not exist. Accordingly, we surveyed under imaginary alternative pricing scenarios and forecasted the use demand of VTIS by using Binary Logit model. Also, for the users who answered that they would use VTIS service in survey, we classified their use's behaviors as four categories and estimated the use ratio to each category by using Ordered Probit model. Last, using sensitivity analysis for results form above, we derived the optimal price that is 2800won in monthly. 145won in payment per call. Then, VTIS service use rate is respectively 65%, 75%.

The Clinical Usefulness of Halo Sign on CT Image of Trauma Patients (외상환자의 전산화 단층촬영소견에서 나타난 달무리 소견의 임상적 유용성)

  • Lee, Seung Yong;Sohn, You Dong;Ahn, Hee Cheol;Kang, Gu Hyun;Choi, Jung Tae;Ahn, Moo Eob;Seo, Jeong Youl
    • Journal of Trauma and Injury
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    • v.20 no.2
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    • pp.144-148
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    • 2007
  • Purpose: The management of hemorrhagic shock is critical for trauma patients. To assess hemorrhagic shock, the clinician commonly uses a change in positional blood pressure, the shock index, an estimate of the diameter of inferior vena cava based on sonography, and an evaluation of hypoperfusion complex shown on a CT scan. To add the finding for the hypoperfusion complex, the 'halo sign' was introduced recently. To our knowledge, this 'halo sign' has not been evaluated for its clinical usefulness, so we designed this study to evaluate its usefulness and to find the useful CT signs for hypoperfusion complex. Methods: The study was done from January 2007 to May 2007. All medical records and CT images of 124 patients with trauma were reviewed, of which 103 patients were included. Exclusion criteria was as follows: 1) age < 15 year old and 2) head trauma score of AIS ${\geq}$ 5. Results: The value of kappa, to assess the inter-observer agreement, was 0.51 (p < 0.001). The variables of the halo-sign-positive group were statistically different from those of the halo-sign-negative group. The rate of transfusion for the halo-sign-positive group was about 10 times higher than that of the halo-sign-negative group and the rate of mortality was about 6 times higher. Conclusion: In the setting of trauma, early abdominal CT can show diffuse abnormalities due to hypoperfusion complex. Recognition of these signs is important in order to prevent an unwanted outcome in hemorrhagic shock. We conclude that the halo sign is a useful one for hypoperfusion complex and that it is useful for assessing the degree of hemorrhagic shock.

Surgical indication analysis according to bony defect size in pediatric orbital wall fractures

  • Kim, Seung Hyun;Choi, Jun Ho;Hwang, Jae Ha;Kim, Kwang Seog;Lee, Sam Yong
    • Archives of Craniofacial Surgery
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    • v.21 no.5
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    • pp.276-282
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    • 2020
  • Background: Orbital fractures are the most common pediatric facial fractures. Treatment is conservative due to the anatomical differences that make children more resilient to severe displacement or orbital volume change than adults. Although rarely, extensive fractures may result in enophthalmos, causing cosmetic problems. We aimed to establish criteria for extensive fractures that may result in enophthalmos. Methods: We retrospectively reviewed the charts of patients aged 0-15 years diagnosed with orbital fractures in our hospital from January 2010 to February 2019. Computed tomography images were used to classify the fractures into linear, trapdoor, and open-door types, and to estimate the defect size. Data on enophthalmos severity (Hertel exophthalmometry results) and fracture pattern and size at the time of injury were obtained from patients who did not undergo surgery during the follow-up and were used to identify the surgical indications for pediatric orbital fractures. Results: A total of 305 pediatric patients with pure orbital fractures were included-257 males (84.3%), 48 females (15.7%); mean age, 12.01±2.99 years. The defect size (p=0.002) and fracture type (p=0.017) were identified as the variables affecting the enophthalmometric difference between the eyes of non-operated patients. In the linear regression analysis, the variable affecting the fracture size was open-door type fracture (p<0.001). Pearson's correlation analysis demonstrated a positive correlation between the enophthalmometric difference and the bony defect size (p=0.003). Using receiver operating characteristic curve analysis, a cutoff value of 1.81 ㎠ was obtained (sensitivity, 0.543; specificity, 0.724; p=0.002). Conclusion: The incidence of enophthalmos in pediatric pure orbital fractures was found to increase with fracture size, with an even higher incidence when open-door type fracture was a cofactor. In clinical settings, pediatric orbital fractures larger than 1.81 ㎠ may be considered as extensive fractures that can result in enophthalmos and consequent cosmetic problems.

Probabilistic Analysis of Blasting Loads and Blast-Induced Rock Mass Responses in Tunnel Excavation (터널발파로 인한 굴착선주변 암반거동의 확률론적 연구)

  • 이인모;박봉기;박채우
    • Journal of the Korean Geotechnical Society
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    • v.20 no.4
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    • pp.89-102
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    • 2004
  • The generated blasting pressure wave initiated under decoupled-charge condition is a function of peak blasting pressure, rise time, and wave-shape function. The peak blasting pressure and the rise time are also the function of explosive and rock properties. The probabilistic distributions of explosive and rock properties are derived from the results of their property tests. Since the probabilistic distributions of explosive and rock properties displayed a normal distribution, the peak blasting pressure and the rise time can also be regarded as a normal distribution. Parameter analysis and uncertainty analysis were performed to identify the most influential parameter that affects the peak blasting pressure and the rise time. Even though the explosive properties were found to be the most influential parameters on the peak blasting pressure and the rise time from the parameter analyses, the result of uncertainty analysis showed that rock properties constituted major uncertainties in estimating the peak blasting pressure and the rise time rather than explosive properties. Damage and overbreak of the remaining rock around the excavation line induced by blasting were evaluated by dynamic numerical analysis. A user-subroutine to estimate the rock damage was coded based on the continuum damage mechanics. This subroutine was linked to a commercial program called 'ABAQUS/Explicit'. The results of dynamic numerical analysis showed that the rock damages generated by the initiation of stopping hole were larger than those from the initiation of contour hole. Several methods to minimize those damages were proposed such as relocation of stopping hole, detailed subdivision of rock classification, and so on. It was found that fracture probability criteria and fractured zones could be distinctively identified by applying fuzzy-random probability.

Vegetable Oil Intake and Breast Cancer Risk: a Meta-analysis

  • Xin, Yue;Li, Xiao-Yu;Sun, Shi-Ran;Wang, Li-Xia;Huang, Tao
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.12
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    • pp.5125-5135
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    • 2015
  • Background: Total fat intake may be associated with increased risk of breast cancer, and fish oil has been suggested as a protection factor to breast cancer. But the effect of vegetable oils is inconclusive. We aimed to investigate the association with high vegetable oils consumption and breast cancer risk, and evaluated their dose-response relationship. Design: We systematically searched the MEDLINE, EMBASE, Cochrane databases, and CNKI updated to December 2014, and identified all observational studies providing quantitative estimates between breast cancer risk and different vegetable oils consumption. Fixed or random effect models were used to estimate summary odds ratios for the highest vs. lowest intake, and dose-response relationship was assessed by restricted cubic spline model and generalized least-squares trend (GLST) model. Results: Five prospective cohort studies and 11 retrospective case-control studies, involving 11,161 breast cancer events from more than 150,000 females, met the inclusion criteria. Compared with the lowest vegetable oils consumption, higher intake didn't increased the risk of breast cancer with pooled OR of 0.88 (95% CIs:0.77-1.01), and the result from dose-response analyses didn't show a significant positive or negative trend on the breast cancer risk for each 10g vegetable oil/day increment (OR=0.98, 95% CIs: 0.95-1.01). In the subgroup analyses, the oils might impact on females with different strata of BMI. Higher olive oil intake showed a protective effect against breast cancer with OR of 0.74 (95% CIs: 0.60-0.92), which was not significant among the three cohort studies. Conclusions: This meta-analyses suggested that higher intake of vegetable oils is not associated with the higher risk of breast cancer. Olive oil might be a protective factor for the cancer occurrence among case-control studies and from the whole. Recall bias and imbalance in study location and vegetable oils subtypes shouldn't be ignored. More prospective cohort studies are required to confirm the interaction of the impact of vegetable oils on different population and various cancer characteristic, and further investigate the relationship between different subtype oils and breast cancer.

Effects of Pyridoxine on Growth Performance and Plasma Aminotransferases and Homocysteine of White Pekin Ducks

  • Xie, Ming;Tang, Jing;Wen, Zhiguo;Huang, Wei;Hou, Shuisheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.12
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    • pp.1744-1748
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    • 2014
  • A dose-response experiment with seven supplemental pyridoxine levels (0, 0.66, 1.32, 1.98, 2.64, 3.30, and 3.96 mg/kg) was conducted to investigate the effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of White Pekin ducks and to estimate pyridoxine requirement for these birds. A total of 336 one-day-old male White Pekin ducks were divided to 7 experimental treatments and each treatment contained 8 replicate pens with 6 birds per pen. Ducks were reared in raised wire-floor pens from hatch to 28 d of age. At 28 d of age, the weight gain, feed intake, feed/gain, and the aspartate aminotransferase, alanine aminotransferase, and homocysteine in plasma of ducks from each pen were all measured. In our study, the pyridoxine deficiency of ducks was characterized by growth depression, decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine. The ducks fed vitamin $B_6$-deficient basal diets had the worst weight gain and feed/gain among all birds and this growth depression was alleviated (p<0.05) when pyridoxine was supplemented to basal diets. On the other hand, plasma aspartate aminotransferase and homocysteine may be the sensitive indicators for vitamin $B_6$ status of ducks. The ducks fed basal diets had much lower aspartate aminotransferase activity and higher homocysteine level in plasma compared with other birds fed pyridoxine-supplemented diets (p<0.05). According to quadratic regression, the supplemental pyridoxine requirements of Pekin ducks from hatch to 28 days of age was 2.44 mg/kg for feed/gain and 2.08 mg/kg for plasma aspartate aminotransferase and the corresponding total requirements of this vitamin for these two criteria were 4.37 and 4.01 mg/kg when the pyridoxine concentration of basal diets was included, respectively. All data suggested that pyridoxine deficiency could cause growth retardation in ducks and the deficiency of this vitamin could be indicated by decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine.

Diagnostic Value of Endorectal Ultrasound in Preoperative Assessment of Lymph Node Involvement in Colorectal Cancer: a Meta-analysis

  • Li, Li;Chen, Shi;Wang, Ke;Huang, Jiao;Liu, Li;Wei, Sheng;Gao, Hong-Yu
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3485-3491
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    • 2015
  • Background: Nodal invasion by colorectal cancer is a critical determinant in estimating patient survival and in choosing appropriate preoperative treatment. The present meta-analysis was designed to evaluate the diagnostic value of endorectal ultrasound (EUS) in preoperative assessment of lymph node involvement in colorectal cancer. Materials and Methods: We systematically searched PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) databases for relevant studies published on or before December 10th, 2014. The sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR) and area under the summary receiver operating characteristics curve (AUC) were assessed to estimate the diagnostic value of EUS. Subgroup analysis and meta-regression were performed to explore heterogeneity across studies. Results: Thirty-three studies covering 3,016 subjects were included. The pooled sensitivity and specificity were 0.69 (95%CI: 0.63-0.75) and 0.77 (95%CI: 0.73-0.82), respectively. The positive and negative likelihood ratios were 3.09 (95%CI: 2.52-3.78) and 0.39 (95%CI: 0.32-0.48), respectively. The DOR was 7.84 (95%CI: 5.56-11.08), and AUC was 0.80 (95%CI: 0.77-0.84). Conclusions: This meta-analysis indicated that EUS has moderate diagnostic value in preoperative assessment of lymph node involvement in colorectal cancer. Further refinements in technology and diagnostic criteria are necessary to improve the diagnostic accuracy of EUS.

Track Stability Assessment for Deep Excavations in Adjacent to Urban Railways (도시철도 인접지반 깊은 굴착 시 궤도 안정성 평가)

  • Jeon, Sang-Soo;Lee, Sang-Seung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.614-627
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    • 2018
  • Urban railway lines have been constructed adjacent to residential buildings and urban areas. The expansion of transportation networks and reconstruction of residential buildings in highly populated urban areas require deep excavations in areas adjacent to urban railways. Mobilized soil stresses and changes in the groundwater level induced by deep excavations results in track irregularities in urban railways. In this study, a three-dimensional finite difference model using the commercial program FLAC3D was adopted to estimate the horizontal displacements of earth retaining structures, settlements of backfill, the stability of track irregularity and underground box structure based on the criteria of each railway organization and its relationships. In deep excavations, a change in groundwater level induces relatively very small differences for track gauge irregularities, whereas relatively large differences for longitudinal irregularities of 72.5%, twist irregularities of 83.3%, cross level irregularities of 61.9%, and alignments of 43.3% were found to be the maximum differences when the horizontal displacement of earth retaining wall and settlement of backfill were 65.1% and 21.4%, respectively, because the groundwater level (GWL) on the ground surface-mobilized tensile strength of the underground box structure exceeds the allowable value. Therefore, three-dimensional numerical analysis was performed in this study. Overall, real-time monitoring should be carried out to prevent railway accidents in advance when a deep excavation adjacent to urban railway structures is constructed.

Relation of the Physico-chemical Properties of Forest Soil to Site Indices of Larix leptolepis Stands (산림 토양의 이화학적 성질과 낙엽송 임분의 지위지수와의 관계)

  • Park, Nam-Chang;Lee, Kwang-Soo;Park, Mun Sueb;Shin, Hyeon Chul;Jun, Kwon Seok;Jung, Su-Young
    • Journal of Korean Society of Forest Science
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    • v.97 no.6
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    • pp.589-596
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    • 2008
  • This study was carried out in order to estimate site indices in un-stocked land by the physico-chemical properties of forest soil and to investigate the distribution of the physico-chemical properties by soil horizons. In Larix leptolepis Gordon stand, 80 sites were selected respectively to A and B horizon in soil. About the analysis method of data there was used stepwise regression analysis. Soil pH and T.N. of the physico-chemical properties turned out to be positively related to the site index. However, O.M. and Avail. $P_2O_5$ in soil were found out negatively related. In the degree of contribution of the variables to site index by each one of the stands, the highly effective variables were Base Sat., C.E.C., Sand, Exch. $Ca^{{+}{+}}$, and Exch. $Mg^{{+}{+}}$ in A horizon, Exch. $Ca^{{+}{+}}$, Base Sat., T.N., Avail. $P_2O_5$, and Clay in B horizon, and Exch. $Ca^{{+}{+}}$ and Base Sat. in both of A and B horizon. In conclusion, these results will provide not only the important criteria for establishment of management forest plan in un-stocked land but also the useful guidance for selecting the suitable sites and trees.

Meta-analysis of Associations between ATM Asp1853Asn and TP53 Arg72Pro Polymorphisms and Adverse Effects of Cancer Radiotherapy

  • Su, Meng;Yin, Zhi-Hua;Wu, Wei;Li, Xue-Lian;Zhou, Bao-Sen
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.24
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    • pp.10675-10681
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    • 2015
  • Background: The ataxia telangiectasia mutated (ATM) protein and p53 play key roles in sensing and repairing radiation-induced DNA double strand breaks (DSBs). Accumulating epidemiological evidence indicates that functional genetic variants in ATM and TP53 genes may have an impact on the risk of radiotherapy-induced side effects. Here we performed a meta-analysis to investigate the potential interaction between ATM Asp1853Asn and TP53 polymorphisms and risk of radiotherapy-induced adverse effects quantitatively. Materials and Methods: Relevant articles were retrieved from PubMed, ISI Web of Science and the China National Knowledge Infrastructure (CNKI) databases. Eligible studies were selected according to specific inclusion and exclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled to estimate the association between ATM Asp1853Asn and TP53 Arg72Pro polymorphisms and risk of radiotherapy adverse effects. All analyses were performed using the Stata software. Results: A total of twenty articles were included in the present analysis. In the overall analysis, no significant associations between ATM Asp1853Asn and TP53 Arg72Pro polymorphisms and the risk of radiotherapy adverse effects were found. We conducted subgroup analysis stratified by type of cancer, region and time of appearance of side effects subsequently. No significant association between ATM Asp1853Asn and risk of radiotherapy adverse effects was found in any subgroup analysis. For TP53 Arg72Pro, variant C allele was associated with decreased radiotherapy adverse effects risk among Asian cancer patients in the stratified analysis by region (OR=0.71, 95%CI: 0.54-0.93, p=0.012). No significant results were found in the subgroup analysis of tumor type and time of appearance of side effects. Conclusions: The TP53 Arg72Pro C allele might be a protective factor of radiotherapy-induced adverse effects among cancer patients from Asia. Further studies that take into consideration treatment-related factors and patient lifestyle including environmental exposures are warranted.