• Title/Summary/Keyword: count time series

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A Study on Performance Evaluation of Various Kriging Models for Estimating AADT (연평균 일교통량 산정을 위한 다양한 크리깅 방법의 성능 평가에 대한 연구)

  • Ha, Jung Ah;Oh, Sei-Chang;Heo, Tae-Young
    • Journal of Korean Society of Transportation
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    • v.32 no.4
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    • pp.380-388
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    • 2014
  • Annual average daily traffic(AADT) serves as important basic data in the transportation sector. AADT is used as design traffic which is the basic traffic volume in transportation planning. Despite of its importance, at most locations, AADT is estimated using short term traffic counts. An accurate AADT is calculated through permanent traffic counts at limited locations. This study dealt with estimating AADT using various models considering both the spatial correlation and time series data. Kriging models which are commonly used spatial statistics methods were applied and compared with each model. Additionally the External Universal kriging model, which includes explanatory variables, was used to assure accuracy of AADT estimation. For evaluation of various kriging methods, AADT estimation error, proposed using national highway permanent traffic count data, was analyzed and their performances were compared. The result shows the accuracy enhancement of the AADT estimation.

Clinical Factors and Perioperative Strategies Associated with Outcome in Preinjury Antiplatelet and Anticoagulation Therapy for Patients with Traumatic Brain Injuries

  • Pang, Chang Hwan;Lee, Soo Eon;Yoo, Heon
    • Journal of Korean Neurosurgical Society
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    • v.58 no.3
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    • pp.262-270
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    • 2015
  • Objective : Long-term oral anticoagulation or antiplatelet therapy has been used with increasing frequency in the elderly. These patients are at increased risk of morbidity and mortality from expansion of intracranial hemorrhage. We conducted a single-center retrospective case control study to evaluate risk factors associated with outcomes and to identify the differences in outcome in traumatic brain injury between preinjury anticoagulation use and without anticoagulation. Methods : A retrospective study of patients who underwent craniotomy or craniectomy for acute traumatic cerebral hemorrhage, between January 2005 and December 2014 was performed. Results : A consecutive series of 50 patients were evaluated. The factors significantly differed between the two groups were initial Prothrombin Time-International Normalized Ratio, initial platelet count, initial Glasgow Coma Scale score, and postoperative intracranial bleeding. Mean Glasgow Outcome Scale (GOS) score were similar between the two groups. In the patient with low-energy trauma only, no significant differences in GOS score, postoperative bleeding and many other factors were observed. The contributing factors to postoperative bleeding was preinjury anticoagulation and its adjusted odds ratio was 12 [adjusted odds ratio (OR), 12.242; p=0.0070]. The contributing factors to low GOS scores, which mean unfavorable neurological outcomes, were age (adjusted OR, 1.073; p=0.039) and Rotterdam scale score for CT scans (adjusted OR, 3.123; p=0.0020). Conclusion : Preinjury anticoagulation therapy contributed significantly to the occurrence of postoperative bleeding. However, preinjury anticoagulation therapy in the patients with low-energy trauma did not contribute to the poor clinical outcomes or total hospital stay. Careful attention should be given to older patients and severity of hemorrhage on initial brain CT.

Near Infrared Spectroscopy for Diagnosis: Influence of Mammary Gland Inflammation on Cow´s Milk Composition Measurement

  • Roumiana Tsenkova;Stefka Atanassova;Kiyohiko Toyoda
    • Near Infrared Analysis
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    • v.2 no.1
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    • pp.59-66
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    • 2001
  • Nowadays, medical diagnostics is efficiently supported by clinical chemistry and near infrared spectroscopy is becoming a new dimension, which has shown high potential to provide valuable information for diagnosis. The investigation was carried out to study the influence of mammary gland inflammation, called mastitis, on cow´s milk spectra and milk composition measured by near infrared spectroscopy (NIRS). Milk somatic cell counts (SCC) in milk were used as a measure of mammary gland inflammation. Naturally occurred variations with milk composition within lactation and in the process of milking were included in the experimental design of this study. Time series of unhomogenized, raw milk spectral data were collected from 3 cow along morning and evening milking, for 5 consecutive months, within their second lactation. In the time of the trial, the investigated cows had periods with mammary gland inflammation. Transmittance spectra of 258 milk samples were obtained by NIRSystem 6500 spectrophotometer in 1100-2400 nm region. Calibration equations for the examined milk components were developed by PLS regression using 3 different sets of samples: samples with low somatic cell count (SCC), samples with high SCC and combined data set. The NIR calibration and prediction of individual cow´s milk fat, protein, and lactose were highly influenced by the presence of mil samples from animals with mammary gland inflammation in the data set. The best accuracy of prediction (i.e. the lower SEP and the higher correlation coefficient) for fat, protein and lactose was obtained for equations, developed when using only “healthy” samples, with low SCC. The standard error of prediction increased and correlation coefficient decreased significantly when equations for low SCC milk were used to predict examined components in “mastitis” samples with high SCC, and vice versa. Combined data set that included samples from healthy and mastitis animals could be used to build up regression models for screening. Further use of separate model for healthy samples improved milk composition measurement. Regression vectors for NIR mild protein measurement obtained for “healthy” and “mastitic” group were compared and revealed differences in 1390-1450 nm, 1500-1740 nm and 1900-2200 nm regions and thus illustrated post-secretory breakdown of milk proteins by hydrolytic enzymes that occurred with mastitis. For the first time it has been found that monitoring the spectral differences in water bands at 1440 nm and 1912 nm could provide valuable information for inflammation diagnosis.

Trends in Epidemiology, Clinical and Histopathological Characteristics of Breast Cancer in Iran: Results of a 17 Year Study

  • Afsharfard, Aboulfazl;Mozaffar, Mohammad;Orang, Elahe;Tahmasbpour, Eisa
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6905-6911
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    • 2013
  • Background: Breast cancer (BC) is the top cancer among women worldwide and the most frequent malignancy among Iranian women over the past few decades. The increasing trend and high mortality rate of BC in the developing world necessitates studies concentrating on its characteristics in countries in Asia. The current study focused on clinical and histopathological features of BC among Iranian females. Materials and Methods: This retrospective study involved 714 Iranian patients with histopathologically proven BC undergoing resection of primary tumours and axillary clearance. Demographic, clinical and histopathological data were obtained and studied between ten year age groups (${\leq}40$ years, 41-50 years, 51-60 years, 61-70 years, and ${\leq}71$ years) in four chronologic phases from 1994-2009. Results: Mean age of patients was $49.4{\pm}13.1$ years. Most of cases (33.2%) were in 41-50 group. Mean size of primary tumors was $3.94{\pm}2.47$ cm and 87.1% of cases had infiltrative ductal carcinoma. Modified radical mastectomy was the most common method of surgery carried out (48.8%). Some 57.1% of tumors were in pT2 and tumor size decreased significantly during the period (p<0.05). The most common BC stage was llla (27%). Lower BC stages (0 and 1) constituted 13.9% of the diagnosed tumors. Our series of patients aged ${\leq}40$ had larger tumors (mean $4.73{\pm}3.02$ cm) compared to older age groups (p=0.003). Lower stages (0 and I) were more frequent among the oldest patients while nearly 50% of patients aged ${\leq}40$ had tumor stage III. We also observed a significant decreasing trend in the mean LN count (p<0.05) and blood vessel invasion (p=0.023) from younger to older age groups. Conclusions: More aggressive disease for younger age groups, earlier peak incidence age and high rate of advanced BC at the time of diagnosis among Iranian women, were the main findings of this study.

Studies on Thermal Resistance of Selected Yeast Strain for Pasteurization of Solid Packed Peach (복숭아 Solid Pack 적정(適定) 살균조건(殺菌條件) 구명(究明)을 위(爲)한 선발(選拔) 효모(酵母)의 열저항성(熱抵抗性)에 관(關)한 연구(硏究))

  • Koo, Young-Jo;Lee, Dong-Sun;Shin, Dong-Hwa;Yu, Tae-Jong
    • Korean Journal of Food Science and Technology
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    • v.13 no.1
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    • pp.43-52
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    • 1981
  • A series of thermal destruction studies of the most heat resistant yeast strain No. 15 among 61 isolates were conducted in order to establish the optimum pasteurization condition of peach solid pack. The results obtained are summarized as follows: 1. A survival curve of the selected yeast strain No. 15 at $58^{\circ}C$ consisted of heat labile and heat stable fraction, showing broken curve. 2. The actively growing cell showed less recovery rate than 10 day rested cell after agitation-growing for 90 hr. For heating menstrua, peptone solution gave higher recovery rate than peach juice. For recovery medium, YM agar gave higher recovery rate than peach juice agar. The selected yeast was more resistant to heat at pH 4.0 than at pH 3.5 in both heating menstrua and recovery medium. 3. Z value of TDT curve of the selected yeast (heating : at pH 3.5 in peach juice. recovery: at pH 3.5 in peach juice agar) was $4.8^{\circ}C$. 4. The selected yeast No. 15 was identified as Torulopsis candida. 5. In the inoculated pack test of 4 oz can, it was concluded that the optimum P.U. 70/5 was 168 (center temp; $78.5^{\circ}C$, initial temp; $18^{\circ}C$, processing time; 18 min, initial yeast count; $1.0{\times}10^7$ per can).

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CM Prospects and Strategies Based on Contract Statistics : 1997 through 2014 (CM산업 수주실적 분석을 통한 CM기업의 발전 방안 - 1997년 ~ 2014년 실적자료 기반 -)

  • Ha, Jiwon;Jung, Youngsoo
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.5
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    • pp.97-107
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    • 2016
  • CM services have been focused on the advancement of the CM industry and expansion to overseas market based on CM capabilities. However, there has been lack of quantitative and comprehensive research to investigate current CM trends and prospects for improving competitiveness. In this sense, the purpose of this study is to statistically analyze total of 3,453 CM service contracts over the past 18 years (between 1997 and 2014) in term of market type, contract size, owner's type, commodity type. Finding of this research reveal that 1) compared to 2005, CM market size in 2015 increased as much as 2.5 times, and that 2) domestic CM projects count for 87.5%, architectural project 88.4%, less than 1 billion won small contracts 75%, respectively. Also, recently as CM company are developing capability and competitiveness, 1) overseas CM market share has grown up to 20% among total CM contract amount, and 2) CM contracts by private owners has increased 3 times demanding the total management services based on high technical capability. Additionally, the result of this paper supports the growth path model proposed by Jung et al. (2014), where a path from Domestic Public (DP3) and Domestic Private (DC2) CM projects towards the expansion to International Private (IC5) contracts was quantitatively analyzed. Implications for other practical issues are also briefly discussed.

An Exploratory Study on the Competition Patterns Between Internet Sites in Korea (한국 인터넷사이트들의 산업별 경쟁유형에 대한 탐색적 연구)

  • Park, Yoonseo;Kim, Yongsik
    • Asia Marketing Journal
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    • v.12 no.4
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    • pp.79-111
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    • 2011
  • Digital economy has grown rapidly so that the new business area called 'Internet business' has been dramatically extended as time goes on. However, in the case of Internet business, market shares of individual companies seem to fluctuate very extremely. Thus marketing managers who operate the Internet sites have seriously observed the competition structure of the Internet business market and carefully analyzed the competitors' behavior in order to achieve their own business goals in the market. The newly created Internet business might differ from the offline ones in management styles, because it has totally different business circumstances when compared with the existing offline businesses. Thus, there should be a lot of researches for finding the solutions about what the features of Internet business are and how the management style of those Internet business companies should be changed. Most marketing literatures related to the Internet business have focused on individual business markets. Specifically, many researchers have studied the Internet portal sites and the Internet shopping mall sites, which are the most general forms of Internet business. On the other hand, this study focuses on the entire Internet business industry to understand the competitive circumstance of online market. This approach makes it possible not only to have a broader view to comprehend overall e-business industry, but also to understand the differences in competition structures among Internet business markets. We used time-series data of Internet connection rates by consumers as the basic data to figure out the competition patterns in the Internet business markets. Specifically, the data for this research was obtained from one of Internet ranking sites, 'Fian'. The Internet business ranking data is obtained based on web surfing record of some pre-selected sample group where the possibility of double-count for page-views is controlled by method of same IP check. The ranking site offers several data which are very useful for comparison and analysis of competitive sites. The Fian site divides the Internet business areas into 34 area and offers market shares of big 5 sites which are on high rank in each category daily. We collected the daily market share data about Internet sites on each area from April 22, 2008 to August 5, 2008, where some errors of data was found and 30 business area data were finally used for our research after the data purification. This study performed several empirical analyses in focusing on market shares of each site to understand the competition among sites in Internet business of Korea. We tried to perform more statistically precise analysis for looking into business fields with similar competitive structures by applying the cluster analysis to the data. The research results are as follows. First, the leading sites in each area were classified into three groups based on averages and standard deviations of daily market shares. The first group includes the sites with the lowest market shares, which give more increased convenience to consumers by offering the Internet sites as complimentary services for existing offline services. The second group includes sites with medium level of market shares, where the site users are limited to specific small group. The third group includes sites with the highest market shares, which usually require online registration in advance and have difficulty in switching to another site. Second, we analyzed the second place sites in each business area because it may help us understand the competitive power of the strongest competitor against the leading site. The second place sites in each business area were classified into four groups based on averages and standard deviations of daily market shares. The four groups are the sites showing consistent inferiority compared to the leading sites, the sites with relatively high volatility and medium level of shares, the sites with relatively low volatility and medium level of shares, the sites with relatively low volatility and high level of shares whose gaps are not big compared to the leading sites. Except 'web agency' area, these second place sites show relatively stable shares below 0.1 point of standard deviation. Third, we also classified the types of relative strength between leading sites and the second place sites by applying the cluster analysis to the gap values of market shares between two sites. They were also classified into four groups, the sites with the relatively lowest gaps even though the values of standard deviation are various, the sites with under the average level of gaps, the sites with over the average level of gaps, the sites with the relatively higher gaps and lower volatility. Then we also found that while the areas with relatively bigger gap values usually have smaller standard deviation values, the areas with very small differences between the first and the second sites have a wider range of standard deviation values. The practical and theoretical implications of this study are as follows. First, the result of this study might provide the current market participants with the useful information to understand the competitive circumstance of the market and build the effective new business strategy for the market success. Also it might be useful to help new potential companies find a new business area and set up successful competitive strategies. Second, it might help Internet marketing researchers take a macro view of the overall Internet market so that make possible to begin the new studies on overall Internet market beyond individual Internet market studies.

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