• Archives of design research
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• v.19 no.3 s.65
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• pp.131-142
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• 2006

The purpose of this study is to develop an online community construct, which proposes an inclusive illustration of the structure of online communities, for online community designers. This study reviewed researches from psychology, sociology, management engineering, and practical reports to understand the characteristics and dynamics of online communities. The proposed online community construct visualizes the cognitive, affective, and behavioral aspects of online community. As the notion of community originates from geographical groups, and with the assumption that geographical community shares identical characteristics with online community, this study reviewed researches about geographical communities as a starting-point. Then the study went through three main perspectives (1) online community attributes, (2) sense of online community and (3) challenges of online community. Then this study proposed an online community construct that encompasses the reviewed frameworks. The online community can be seen as a congregation of members from two sources. One is from the 'Shared Goal' that meets the personal needs. Given the shared goal, members gather into the community without personal relationship and have more chances to feel the sense of belonging to their needs fulfillment or benefit. This befitting tendency leads to strengthening of membership. Public online forums fall under this classification. The other source is from the emotional connections that are already initiated by personal and casual contacts in the real world. The network of emotional connection can evolve into an online congregation of people under faint boundaries. Although there is no (or weak) shared goal, members are strongly bound to other members. Personal homepage or web log (blog) can be classified as an example of relationship-oriented community.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1239-1247
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• 2010

In this paper, we were researched decision problem called an optimal release policies after testing a software system in development phase and transferring it to the user. The applied model of release time exploited infinite failure non-homogeneous Poisson process This infinite failure non-homogeneous Poisson process is a model which reflects the possibility of introducing new faults when correcting or modifying the software. The intensity function used Gompertz, Preto and Log-logstic pattern which has the efficient various property. Thus, optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement becomes an optimal release policies. In a numerical example, after trend test applied and estimated the parameters using maximum likelihood estimation of inter-failure time data, estimated software optimal release time.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4839-4842
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• 2014

Background: Although the Cox's proportional hazard model is the popular approach for survival analysis to investigate significant risk factors of cancer patient survival, it is not appropriate in the case of log-term disease free survival. Recently, cure rate models have been introduced to distinguish between clinical determinants of cure and variables associated with the time to event of interest. The aim of this study was to use a cure rate model to determine the clinical associated factors for cure rates of patients with breast cancer (BC). Materials and Methods: This prospective cohort study covered 305 patients with BC, admitted at Shahid Faiazbakhsh Hospital, Tehran, during 2006 to 2008 and followed until April 2012. Cases of patient death were confirmed by telephone contact. For data analysis, a non-mixed cure rate model with Poisson distribution and negative binomial distribution were employed. All analyses were carried out using a developed Macro in WinBugs. Deviance information criteria (DIC) were employed to find the best model. Results: The overall 1-year, 3-year and 5-year relative survival rates were 97%, 89% and 74%. Metastasis and stage of BC were the significant factors, but age was significant only in negative binomial model. The DIC also showed that the negative binomial model had a better fit. Conclusions: This study indicated that, metastasis and stage of BC were identified as the clinical criteria for cure rates. There are limited studies on BC survival which employed these cure rate models to identify the clinical factors associated with cure. These models are better than Cox, in the case of long-term survival.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7497-7500
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• 2013

Background: This study concerns clinical characteristics and survival of renal cell carcinoma (RCC) patients in University Malaya Medical Centre (UMMC), as well as the prognostic significance of presenting symptoms. Materials and Methods: The clinical characteristics, presenting symptoms and survival of RCC patients (n=151) treated at UMMC from 2003-2012 were analysed. Symptoms evaluated were macrohaematuria, flank pain, palpable abdominal mass, fever, lethargy, loss of weight, anaemia, elevated ALP, hypoalbuminemia and thrombocytosis. Univariate and multivariate Cox regression analyses were performed to determine the prognostic significance of these presenting symptoms. Kaplan Meier and log rank tests were employed for survival analysis. Results: The 2002 TNM staging was a prognostic factor (p<0.001) but Fuhrman grading was not significantly correlated with survival (p=0.088). At presentation, 76.8% of the patients were symptomatic. Generally, symptomatic tumours had a worse survival prognosis compared to asymptomatic cases (p=0.009; HR 4.74). All symptoms significantly affect disease specific survival except frank haematuria and loin pain on univariate Cox regression analysis. On multivariate analysis adjusted for stage, only clinically palpable abdominal mass remained statistically significant (p=0.027). The mean tumour size of palpable abdominal masses, $9.5{\pm}4.3cm$, was larger than non palpable masses, $5.3{\pm}2.7cm$ (p<0.001). Conclusions: This is the first report which includes survival information of RCC patients from Malaysia. Here the TNM stage and a palpable abdominal mass were independent predictors for survival. Further investigations using a multicentre cohort to analyse mortality and survival rates may aid in improving management of these patients.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.3
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• pp.59-68
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• 2005

The rainfall-runoff potential of Jangseong reservoir watershed was studied based on SCS (Soil Conservation Service, which is now the NRCS, Natural Resources Conservation Service, USDA) runoff curve number (CN) technique. Precipitation and reservoir operation data had been collected. The rainfall-runoff pairs from the watershed for ten years was estimated using reservoir water balance analysis using reservoir operation records. The maximum retention, S, for each storm event from rainfall-runoff pair was estimated for selected storm events. The estimated S values were arranged in descending order, then its probability distribution was determined as log-normal distribution, and associated CNs were found about probability levels of Pr=0.1, 0.5, and 0.9, respectively. A subwatershed that has the similar portions of land use categories to the whole watershed of Jangseong reservoir was selected and hydrologic monitoring was conducted. CNs for subwatershed were determined using observed data. CNs determined from observed rainfall-runoff data and reservoir water balance analysis were compared to the suggested CNs by the method of SCS-NEH4. The $CN_{II}$ measured and estimated from water balance analysis in this study were 78.0 and 78.1, respectively. However, the $CN_{II}$, which was determined based on hydrologic soil group, land use, was 67.2 indicating that actual runoff potential of Jangseong reservoir watershed is higher than that evaluated by SCS-NEH4 method. The results showed that watershed runoff potential for large scale agricultural reservoirs needs to be examined for efficient management of water resources and flood prevention.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7271-7275
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• 2014

Background: The aim of the present study was to evaluate the presentation, clinical course and outcome between children and young adults with differentiated thyroid cancer (DTC) treated in our hospital. Materials and Methods: The medical records of 145 patients with DTC who underwent surgery followed by radioiodine and thyroid hormone (TSH) suppression were retrospectively reviewed. The follow up was between January 2006 and June 2012. These patients consisted of 38 children (age${\leq}18y$) and 107 young adult patients (age${\leq}30y$). The clinical characteristics and outcome were analyzed and compared, and the progression-free survival (PFS) was evaluated using the Kaplan-Meier method. Results: At initial diagnosis, a greater degree of extra thyroidal extension was found in children than adults patients (p<0.001). However, there was no significant difference between the two groups with regard to the tumor size and the presence of lymph node or distant metastasis (p=0.172, p=0.050 and p=0.068, respectively). The extent of surgery and the cumulative or mean dose of radioiodine were similar in both groups. During the follow up, the overall survival rate was 100% for both groups, and the PFS rate was similar in children and in young adults group (log rank test, ${\chi}^2$=0.126, p=0.723). Conclusions: In comparison to the young adult patients, DTC in children presents with more aggressive behavior, but outcomes are similar between the two groups after the intensive management of surgery followed by radioiodine and TSH suppression therapy.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.149-161
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• 2016

Fishing characteristics of Korean tuna purse seine fishery in the Pacific Ocean were investigated using logbook data compiled from captain onboard and the statistical data from 1980 to 2014. Changes in fishing ground and correlation between marine environmental factors and fishing patterns were investigated using Oceanographic index. The proportion of unassociated set was higher than that of associated set. The catch proportion of yellowfin was higher in the unassociated set, while that of skipjack and bigeye was higher in the associated set. Due to vessels, fishing gears and Korean captains' high-level of skills in fishing technology optimized for the unassociated set and preference of large fishes, especially large yellowfin tuna, it showed unique fishing characteristics focusing on the unassociated set. As for fishing distributions of Korean tuna purse seine fishery and impacts of oceanographic conditions on the fishery, the main fishing ground was concentrated on the area of $5^{\circ}N{\sim}10^{\circ}S$, $140^{\circ}E{\sim}180^{\circ}$ through the decades. When stronger El-nino occurred, the range of fishing ground tended to expand and main fishing ground moved to the eastern part of western and central Pacific Ocean. During this season, yellowfin tuna had high CPUE and catch proportion of yellowfin tuna in the eastern part also increased. As for the proportion of fishing effort by set type, proportion of log associated set was high during El-nino season while that of FAD associated set was high during La-nina season.

• Food Science of Animal Resources
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• v.35 no.1
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• pp.108-113
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• 2015

The purpose of this study was to develop predictive models for the growth of Listeria monocytogenes in pork Bulgogi at various storage temperatures. A two-strain mixture of L. monocytogenes (ATCC 15313 and isolated from pork Bulgogi) was inoculated on pork Bulgogi at 3 Log CFU/g. L. monocytogenes strains were enumerated using general plating method on Listeria selective medium. The inoculated samples were stored at 5, 15, and $25^{\circ}C$ for primary models. Primary models were developed using the Baranyi model equations, and the maximum specific growth rate was shown to be dependent on storage temperature. A secondary model of growth rate as a function of storage temperature was also developed. As the storage temperature increased, the lag time (LT) values decreased dramatically and the specific growth rate of L. monocytogenes increased. The mathematically predicted growth parameters were evaluated based on the modified bias factor ($B_f$), accuracy factor ($A_f$), root mean square error (RMSE), coefficient of determination ($R^2$), and relative errors (RE). These values indicated that the developed models were reliably able to predict the growth of L. monocytogenes in pork Bulgogi. Hence, the predictive models may be used to assess microbiological hygiene in the meat supply chain as a function of storage temperature.

• Archives of Craniofacial Surgery
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• v.18 no.2
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• pp.105-111
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• 2017

Background: The author analyse the impact of extracapsular lymph node spread and bone engagement in the ipsilateral neck of patients suffering squamous cell carcinoma (SCC) of the lower lip. Methods: The data of 56 neck dissections performed in patients suffering SCC of the lower lip between January 2000 and December 2008 were retrospectively analysed. Statistical analysis was performed with the Kaplan-Meier life table method, and the survival rate was investigated with the log rank statistic and significance test. The values were considered statistically significant at p<0.05. Results: Nine patients took advantage from simultaneous treatment of tumor and prophylactic neck dissection (level I-III), reaching 100% survival rate. Patients suffering metastasized disease, who received radical neck dissection at the time of tumor treatment, presented 83.3% survival rate. Patients who underwent previous surgery and radiotherapy presented worse prognosis although radical neck dissection in case of extra-capsular spread only (24.7%) and osseous engagement (22.2%). Conclusion: Prophylactic neck dissection (level I-III) is recommended in T3-T4 N0 SCC. Simultaneous treatment of tumor and cervical lymph nodes provides a better prognosis as respect to delayed nodal management. Extra-capsular spread with or without bone engagement represents independent risk factor responsible for high mortality rate of SCC of the lower lip.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.157-167
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• 2017

Millions of People die every year from diseases caused by exposure to outdoor air pollution. Especially, one of the most severe types of air pollution is fine particulate matter (PM10, PM2.5). South Korea also has been suffered from severe PM. This paper analyzes regional risks induced by PM10 and PM2.5 that have affected domestic area of Korea during 2014~2016.3Q. We investigated daily maxima of PM10 and PM2.5 data observed on 284 stations in South Korea, and found extremely high outlier. We employed extreme value distributions to fit the PM10 and PM2.5 data, but a single distribution did not fit the data well. For theses reasons, we implemented extreme mixture models such as the generalized Pareto distribution(GPD) with the normal, the gamma, the Weibull and the log-normal, respectively. Next, we divided the whole area into 16 regions and analyzed characteristics of PM risks by developing the FN-curves. Finally, we estimated 1-month, 1-quater, half year, 1-year and 3-years period return levels, respectively. The severity rankings of PM10 and PM2.5 concentration turned out to be different from region to region. The capital area revealed the worst PM risk in all seasons. The reason for high PM risk even in the yellow dust free season (Jun. ~ Sep.) can be inferred from the concentration of factories in this area. Gwangju showed the highest return level of PM2.5, even if the return level of PM10 was relatively low. This phenomenon implies that we should investigate chemical mechanisms for making PM2.5 in the vicinity of Gwangju area. On the other hand, Gyeongbuk and Ulsan exposed relatively high PM10 risk and low PM2.5 risk. This indicates that the management policy of PM risk in the west side should be different from that in the east side. The results of this research may provide insights for managing regional risks induced by PM10 and PM2.5 in South Korea.