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Impact of Heterogeneous Dispersion Parameter on the Expected Crash Frequency (이질적 과분산계수가 기대 교통사고건수 추정에 미치는 영향)

  • Shin, Kangwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.9
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    • pp.5585-5593
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    • 2014
  • This study tested the hypothesis that the significance of the heterogeneous dispersion parameter in safety performance function (SPF) used to estimate the expected crashes is affected by the endogenous heterogeneous prior distributions, and analyzed the impacts of the mis-specified dispersion parameter on the evaluation results for traffic safety countermeasures. In particular, this study simulated the Poisson means based on the heterogeneous dispersion parameters and estimated the SPFs using both the negative binomial (NB) model and the heterogeneous negative binomial (HNB) model for analyzing the impacts of the model mis-specification on the mean and dispersion functions in SPF. In addition, this study analyzed the characteristics of errors in the crash reduction factors (CRFs) obtained when the two models are used to estimate the posterior means and variances, which are essentially estimated through the estimated hyper-parameters in the heterogeneous prior distributions. The simulation study results showed that a mis-estimation on the heterogeneous dispersion parameters through the NB model does not affect the coefficient of the mean functions, but the variances of the prior distribution are seriously mis-estimated when the NB model is used to develop SPFs without considering the heterogeneity in dispersion. Consequently, when the NB model is used erroneously to estimate the prior distributions with heterogeneous dispersion parameters, the mis-estimated posterior mean can produce large errors in CRFs up to 120%.

Numerical Experiments of Coastal Upwelling Occurred by Summer Winds in the East Sea of Korea (한국 동해 연안에서 하계 바람에 의해 발생하는 연안용승에 관한 수치실험)

  • Seo, Ho-San;Lim, Woo-Hyun;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.4
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    • pp.347-353
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    • 2017
  • In this study, numerical experiments were conducted to identify distribution of rising flow and flux in the East Sea of Korea, where the coastal upwelling occurs. Temperature and salinity data from CTD observations and NIFS during summer 2013 were applied to the model. Numerical experiments were carried out with different wind speed (3, 6 m/s and 9 m/s) and direction (southerly and southwesterly), which represent the most frequent in summer conditions. As a result of calculation, upwelling flow rate was found to be highest in Pohang between five coasts(Hupo, Youngduk, Pohang, Ulsan and Busan). Comparing with southerly wind conditions, the rising flow rate is about 1.5 times greater when southwesterly wind was applied. Horizontal diffusion of the upwelling area is expected to have a speed of 17~22 km/day when a 9 m/s southwesterly wind is applied. If this wind continues over one week, a cold pool will be generated by upwelling that may reach to the Ulleung area.

Relative Frequency of Oral Malignancies and Oral Precancer in the Biopsy Service of Jazan Province, 2009-2014

  • Idris, AM;Vani, NV;Saleh, Sanna;Tubaigy, Faisal;Alharbi, Fahd;Sharwani, Abubkr;Tadrus, Nabil;Warnakulasuriya, Saman
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.2
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    • pp.519-525
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    • 2016
  • Background: The objective of this study was to report the types and relative frequency of oral malignancies and precancer in the Jazan region of Saudi Arabia during the period 2009-2014. Materials and Methods: Pathology reports were retrieved from the archives of Histopathology Department, King Fahd hospital in Jazan. Demographic data on tobacco habits, clinical presentation and histologic grading of oral precancer and cancer cases were transcribed from the files. Results: 303 (42.7%) oral pre-malignant and malignant cases were found out of 714 oral biopsy lesions. A pathology diagnosis of squamous cell carcinoma (85.1%) was most frequent, followed by premalignant lesions/epithelial dysplasia (8.6%), verrucous carcinoma (3.3%) and malignancy of other histological types (3%) such as ameloblastic carcinoma, salivary gland malignancy and sarcomas. Oral squamous cell carcinoma was predominant in females with a male to female ratio of 1:1.9. Patient age ranged from 22 to 100 years with a mean of $65{\pm}13.9$. Almost 44.6% of oral cancer had occurred after 65 years of age. Only 16.3% cases were reported in patients younger than 50 years, predominantly females. The majority of female patients had the habit of using shammah with a long duration of usage for more than 45 years. Buccoalveolar mucosa (52.3%) was the common site of involvement followed by tongue/floor of the mouth (47.7%) and clinically presented mostly as ulceration/swelling clinically. Moderately differentiated tumours (53.9%) were common followed by well differentiated (32.2%) and poorly differentiated tumours (5.8%). The prevalence of oral verrucous carcinoma (3.3%) was comparatively low with an equal distribution in both males and females. Both bucco-alveolar mucosa and tongue were predominantly affected. Oral precancer/epithelial dysplasia (8.6%) was common in females with a shammah habit. Bucco-alveolar mucosa was commonly involved and clinically presented mostly as white/red patches. Most cases were mild followed by moderate and severe dysplasia. Tumours of other histological types (3%) include 1 ameloblastic carcinoma, 3 malignant salivary gland tumours and 5 sarcomas. Conclusions: In this study, it was found that oral cancers reported in the pathology service to be a common occurrence. This study reconfirms previous reports of the high burden of oral cancer in this population This indicates that conventional preventive programs focused on oral cancer are in need of revision. In addition, further research into identifying new risk factors and molecular markers for oral cancer are needed for screening high risk individuals.

A Retrospective Multicenter Evaluation of Cutaneous Melanomas in Turkey

  • Gamsizkan, Mehmet;Yilmaz, Ismail;Buyukbabani, Nesimi;Demirkesen, Cuyan;Demiriz, Murat;Cetin, Emel Dikicioglu;Ince, Umit;Akalin, Taner;Demirkan, Nese Calli;Lebe, Banu;Erdem, Ozlem;Gokoz, Ozay;Sakiz, Damlanur;Demireli, Peyker Temiz;Astarci, Hesna Muzeyyen;Adim, Saduman Balaban;Zemheri, Itir Ebru;Acikalin, Arbil;Yaman, Banu;Aydin, Ovgu;Bassorgun, Cumhur Ibrahim
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10451-10456
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    • 2015
  • Background: We defined melanoma distribution in a large series of Turkish patients and evaluated the prognostic parameters of melanomas. Materials and Methods: A total of 1574 patients' data was retrospectively collected at 18 centers in Turkey. Demographic characteristics were questioned and noted. Prognostic parametres were evaluated based on sentinel lymph node involvement. Results: Mean age was 56.7 (4-99) years. While 844 (53.6%) cases were male, 730 (46.4%) cases were female. One thousand four hundred forty-seven (92%) cases were invasive melanoma and 127 (8%) cases were in-situ melanoma. The most common histopathological form was the superficial spreading melanoma (SSM) which was found in 549 patients (37.9%). It was followed by nodular melanoma in 379 (26.2%), acral lentiginous melanoma (ALM) in 191 (13.2%) and lentigo maligna melanoma in 132 (9.1%), respectively. On univariate analysis, lymphovascular invasion (p<0.001), tumor thickness (p<0.001), histopathological subtype (p<0.001), Clark level (p=0.001), ulceration (p<0.001), ${\geq}6/mm^2$ mitosis (p=0.005), satellite formation (p=0.001) and gender (p=0.03) were found to be associated with sentinel lymph node positivity. Regression was associated with sentinel lymph node negativity (p=0.017). According to multivariate analysis, lymphovascular invasion and tumor thickness were significant independent predictive factors of SLN positivity. Patient age, tumor localization, precursor lesions, lymphocytic infiltration and neurotropism were not related with sentinel lymph node involvement. Conclusions: In this retrospective analysis, it was found that the prevalence of SSM is at a lower rate while the prevalence of ALM is at a higher rate when compared to western countries. According to Breslow index; most of the melanoma lesions' thickness were greater than 2 mm, corresponding Clark IV. Vascular invasion and tumor thickness are the most important factors for sentinel lymph node involvement.

Gene Silencing of β-catenin by RNAi Inhibits Proliferation of Human Esophageal Cancer Cells by Inducing G0/G1 Cell Cycle Arrest

  • Wang, Jin-Sheng;Ji, Ai-Fang;Wan, Hong-Jun;Lu, Ya-Li;Yang, Jian-Zhou;Ma, Li-Li;Wang, Yong-Jin;Wei, Wu
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2527-2532
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    • 2012
  • Objectives: The aim of the present study was to explore mechanisms underlying the effects of down-regulating ${\beta}$-catenin expression on esophageal carcinoma (EC) cells. Methods: Cell cycle distribution and apoptosis were determined using flow cytometry and annexin V apoptosis assay, respectively. Transmission electron microscopy (TEM) was used to examine changes in ultrastructure, while expression of cyclin D1 protein and mRNA was detected by western blot and real-time PCR. Proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated kinase (ERK) 1-2 were evaluated by Western blot analysis. PCNA labeling index (LI) was determined by immunocytochemistry. Results: Compared with pGen-3-con transfected and Eca-109 cells, the percentage of G0/G1-phase pGen-3-CTNNB1 transfected cells was obviously increased (P<0.05), with no significant difference among the three groups with regard to apoptosis (P>0.05). pGen-3-CTNNB1 transfected cells exhibited obvious decrease in cyclin D1 mRNA and protein expression (P<0.05) and the ultrastructure of Eca-109 cells underwent a significant change after being transfected with pGen-3-CTNNB1, suggesting that down-regulating ${\beta}$-catenin expression can promote the differentiation and maturation. The expression of PCNA and the ERKI/2 phosphorylation state were also down-regulated in pGen-3-CTNNB1 transfected cells (P<0.05). At the same time, the PCNA labeling index was decreased accordingly (P<0.05). Conclusion: Inhibition of EC Eca-109 cellproliferation by down-regulating ${\beta}$-catenin expression could improve cell ultrastructure by mediating blockade in G0/G1 through inhibiting cyclin D1, PCNA and the MAPK pathway (p-ERK1/2).

The Vegetational History of korea During the Holocene Period (홀로세 중 한국의 식생사)

  • 강우석
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.9-22
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    • 1994
  • The vegetational and environmental history of Korea during the Holocene period has reconstructed by the use of folral, palaeoclimatogical, archaeological data and written records. From 10,000 to 6,700 yeat B.P. in mid-eastern Korea, deciduous broadieaved trees gradually increased trees, notably at c.8,000 years B.P. From 6,700 to 4,500 years B.P., the vegetation remained dominated by Quercus and pinus(Diploxylon). Vegetational informations suggest the postglacial hypsithermal from c.8,000 to 4,500 years b.p. After 4,500 until 1,400 years B.P., the admixture of cryophilous trees in midland and thermophilous trees in south seems to imply the latitudinal divisions of vegetation and climate. The presence of cultivated rice pollen as well as non-arboreal pollen and spores indicates an increased rate of deforestation. From 1,400 years B.P., there was a sharp decrease in the representation of temperate trees, but the presence of the cryophilous genera Abies and pinus (Haploxylon) is noticea-ble and might be related to the occurrence of Little Ice Age. Fossil pollen diagram from western Korea and eastern Korea since 6,250 and 10,000 yeats B.P., respectively have enabled to compare vegetational dis-tribution patterns and changes in the Holocene period. In western Korea, Alnus- dominated vegetation continued from 6,250 to 1,500 years B.P., but pinus took over Alnus from 1,500 years B.P. In eastern Korea, however, Quercus and pinus dominated from 10,000 to 2,000 years B.P., but pinus be-came predominant from 2,000 years B.P. On a time- spatial basis, different vegetational distribution pattern can be recognised between western and east-ern Korea. The use of seven historical records which is unique to Korea also enabled to reconstruct the distributional pattern and temporal change of vegetation from 1425 to 1928.

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Quality of Dry Noodle Prepared with Wheat Flour and Immature Rubus coreanus (Bogbunja) Powder Composites (미숙복분자 분말을 첨가한 건면의 품질특성)

  • Lee, Yong-Nim;Song, Guen-Seoup;Kim, Young-Soo
    • Applied Biological Chemistry
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    • v.43 no.4
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    • pp.271-276
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    • 2000
  • Dry noodles were prepared with wheat flour and immature Rubes coreanus (Bogbunja) powder, and the effects of added immature bogbunja powders on dough rheology and noodle quality were examined. Particle size distribution of immature bogbunja powder ranged from 0.04 to $500\;{\um}m$, which was different from that of wheat flour. The initial pasting temperature, peak and final viscosities as well as setback increased in amylograph with the increase of immature bogbunja powder. The water absorption and dough development time increased, but the dough stability decreased in farinograph with the increase of immature bogbunja powder. Decrease of L and b values and increase of a value were shown with the increase of immature bogbunja powder in wheat flour-immature bogbunja powder composite as well as dry noodles. The cooked weight and volume of noodles decreased, but the cooking loss increased with the addition of immature bogbunja powder. Most of texture parameters (hardness, cohesiveness, chewiness, gumminess and tension) of cooked noodles decreased with the addition of immature bogbunja powder. From the result of sensory evaluation, dry noodles containing 1 and 2% immature bogbunja powder were rated as higher quality dry noodles than the others.

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Seasonal Variation of Picoplankton Community in Lake Juam (주암호에서 미세조류의 계절적 군집 변화)

  • Cheong, Cheong-Jo
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.3
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    • pp.271-277
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    • 2010
  • The purpose of this study is to investigate the seasonal variation of picoplankton community in Lake Juam depending on the change of physico-chemical factors such as rainfall, water depth, DO and pH. The concentration of chlorophyll-a was most high as 18.03 mg/$m^3$ in July when the rainfall and water temperature were highest. The concentration was gradually decreased in October, April and that of January was decreased most low as 1.86 mg/$m^3$. The highest concentration of the Chl-a was shown at 2 and 5 m of water depth than surface, and the concentration was gradually decreased when the water depth becomes deep. Overall, microplankton was the highest rate as 33.9~54.2%, nanoplankton was 24.3~30.5% and picoplankton was 21.6~41.2%. Picoplankton was included as considerable concentration in the water of Juam lake. Therefore it is necessary to remove thoroughly the picoplankton in the water treatment processes such coagulation·sedimentation and sand filtration. The protoplasm released from destruction of picoplankton by chlorine has high possibility to cause regrowth of bacteria and pathogenic microorganism in the distribution system by playing the role of the assimilable organic carbon.

Seasonal Variations of Water Quality in the Coastal Sea of Jungmun Resort Complex in Jeiu Island (제주도 중문관광단지 연안해역 수질의 계절변동)

  • Jang Seung-Min;Choi Young-Chan
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.5 no.2
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    • pp.3-18
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    • 2002
  • This study has been carried out to find the water Quality in coastal sea of fungmun area, southern Jeju Island. In-situ observations and water sampling had been made every month from July 1997 to June 2000. The distributions of water temperature and salinity over the study area have been 13.8~27.0℃ and 30.0~34.7‰, respectively. Salinity is showed low salinity from June to September (rainy season) because of rain. Tsushima Warm Waters (TWW) as ≥15℃ and ≥34‰ influence the adjacent sea around Jeju Island all year round. Yangtse Coastal Waters (YCW) influence the surface layer around Jeju from June to September and so strong stratification (termocline, halocline) resulted at the depth of between 20~30m at outer-sea. However the stratification does not happen even in summer at inner-sea, which seem to be caused due to vertical mixing by wind, waves and tides. A water mass of high value of water temperature and salinity (respectively 14.1~17.7℃, 33.9~34.1‰) stayed at the lower layer in outer-sea all the year round. It is probably formed by mixing between TWW and YSBCW(Yellow Sea Bottom Cold Water). The mean value of DO was the lowest in summer and the highest in winter. COD and TH were the highest in summer and the lowest in winter. However, TP showed the lowest value in summer season, because the mean value of N/P ratio was over 16. The mean of N/P ratio was under 16 in other seasons. The phosphate would be a limiting factor in the growth of phytoplanHon in summer. Nitrate would be a limiting factor in other seasons. Distribution of chlorophyll a did not show any seasonal change in the study period, but especially increased during April and May in the first year(1998) and the second year(1999) all over the study area, which suggested that phytoplankton inhabitation distributed widely in the study area. The space averaged values were the highest for TIN in rainy season and lower for TP in rainy season than in other seasons. It suggests that river runoff influences the inner-sea.

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The Dynamic Research of Mobile and PC Online Media Visit Activities Effects on The E-Commerce Site Visit (모바일, PC온라인 매체 방문 행동이 쇼핑 사이트 방문에 미치는 영향에 대한 동태적 연구)

  • Lee, Dong Il;Kim, Hyun Gyo
    • Journal of the Korean Operations Research and Management Science Society
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    • v.39 no.4
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    • pp.85-95
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    • 2014
  • In the e-commerce, the conversion into the multi-media is the important issue. According to the research by Nielsen Korea, the 83% of customers who purchase the products in the e-commerce utilize multi-channel to buy the products such as mobile and online [3]. Thus, to effectively implement online advertising, marketers should understand the customers' path [15] in the multi-channel. The study of the multi-site activities plays an important role to predict customers' purchase [28]. To explain the e-commerce site visit activities of customers, we have developed research model in terms of the online advertising. This research model is based on the study of Moe and Fader [23]. There are two types of composition in the research model. First, general site visit as an exploratory search have net effect on the shopping site visit because customers could acquire or develop information on the e-commerce site via online advertising. Secondly, the e-commerce site visit as a goal-directed search cause threshold of the e-commerce site visit because customers could achieve their goal. When the threshold is increased, the probability of a shopping site visit is decreased and vice versa. Thus, we have investigated the impact of customers' previous visit activities (general site visit and shopping site visit) on the next e-commerce site visit in terms of dynamic view. Research data was provided by Cheil World Wide. This panel data include mobile and online log data of panelists from Jan. 2013 to March 2013. As the results, the customers' e-commerce site visit on the online media would decrease the probability of e-commerce site visit because these visit activities increase the threshold of e-commerce site visit. This result is similar with the previous study [23]. Otherwise, since e-commerce site visit on the mobile media decrease the threshold, the customers' probability of e-commerce site visit would increase In summary, the site visit activities on the mobile could improve the probability of e-commerce site visits.