• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.1-8
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• 2018

K-means algorithm is one of the most popular and widely used clustering method because it is easy to implement and very efficient. However, this method has the limitation to be used with fixed number of clusters because of only considering the intra-cluster distance to evaluate the data clustering solutions. Silhouette is useful and stable valid index to decide the data clustering solution with number of clusters to consider the intra and inter cluster distance for unsupervised data. However, this valid index has high computational burden because of considering quality measure for each data object. The objective of this paper is to propose the fast and simple speed-up method to overcome this limitation to use silhouette for the effective large-scale data clustering. In the first step, the proposed method calculates and saves the distance for each data once. In the second step, this distance matrix is used to calculate the relative distance rate ($V_j$) of each data j and this rate is used to choose the suitable number of clusters without much computation time. In the third step, the proposed efficient heuristic algorithm (Group search optimization, GSO, in this paper) can search the global optimum with saving computational capacity with good initial solutions using $V_j$ probabilistically for the data clustering. The performance of our proposed method is validated to save significantly computation time against the original silhouette only using Ruspini, Iris, Wine and Breast cancer in UCI machine learning repository datasets by experiment and analysis. Especially, the performance of our proposed method is much better than previous method for the larger size of data.

• Archives of Plastic Surgery
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• v.48 no.5
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• pp.473-482
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• 2021

Background The increasing number of bilateral breast cancer patients has been accompanied by a growing need for bilateral mastectomy with immediate reconstruction. However, little research has investigated the complications and aesthetic outcomes related to bilateral reconstruction. Therefore, we analyzed retrospective data comparing the outcomes of bilateral reconstruction using deep inferior epigastric perforator (DIEP) flaps or implants. Methods This study included 52 patients (24 DIEP group and 28 implant group) who underwent bilateral mastectomy with immediate reconstruction between 2010 and 2020. Patient demographics, surgical characteristics, and complications were recorded. The difference between the left and right position of the nipple-areolar complex with respect to the sternal notch point at the clavicle was measured, and breast symmetry was evaluated. Results The average weight of breasts reconstructed with DIEP flaps (417.43±152.50 g) was higher than that of breasts with implants. The hospitalization period and operation time were significantly longer in the DIEP group. Early complications were significantly more common in the implant group (36.53%) than in the DIEP group. The angles between the nipples and the horizontal line were 1.09°±0.71° and 1.75°±1.45° in the DIEP and implant groups, respectively. Conclusions Although the surgical burden is lower, breast reconstruction using implants requires greater attention with respect to implant positioning, asymmetry, and complications than DIEP flap reconstruction. DIEP flap reconstruction has a prolonged operation time and a high risk of flap failure, but yields excellent cosmetic results and does not require intensive follow-up. Patients should be consulted to determine the most suitable option for them.

• Archives of Craniofacial Surgery
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• v.24 no.5
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• pp.211-217
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• 2023

Background: Oral cavity cancers, the second most common type in India, are responsible for 10% of the overall cancer burden. With a recurrence rate of 30% to 40% and a 5-year survival rate of 50%, these malignancies account for substantial morbidity and mortality. Despite advances in treatment modalities, survival rates following treatment completion have not improved significantly. The present study aimed to establish specific epidemiological and pathological factors responsible for recurrence after treatment completion in buccal mucosa cancers. Methods: A retrospective analysis of the data of 116 patients treated for biopsy-proven cancers of the buccal mucosa was undertaken 1 year after treatment completion. Factors such as age, sex, education, lymphovascular invasion, extranodal extension (ENE), perineural invasion, depth of invasion, and pathological margin status were compared between patients who presented with recurrence and those who did not. Statistical significance was set at p< 0.05. Results: Of the 116 patients, 40 (34.5%) developed a recurrent disease within 1 year. The mean age of the study population was 43.3 years, and males constituted 91.4% of the included patients. Ipsilateral buccal mucosa was the commonest site of disease recurrence. Neck node metastasis, ENE, and margins of resection < 5 mm were significantly related to the recurrence of disease. However, surprisingly, lymphovascular invasion, perineural invasion, and depth of invasion > 10 mm did not show statistically significant associations. Conclusion: Neck node metastasis, ENE, and margins of resection < 5 mm were the histopathological factors associated with recurrence in cancers of the buccal mucosa.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1747-1753
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• 2013

Background: It is projected that low and middle-income countries will bear a major burden of tobacco related morbidity and mortality, yet, only limited information is available on the determinants of smoking initiation among youth in Africa. This study aimed to assess the determinants of smoking initiation and susceptibility to future smoking among a population of high school school students in Lagos, Nigeria. Materials and Methods: Baseline data from an intervention study designed to assess the effect of an anti-smoking awareness program on the knowledge, attitudes and practices of adolescents was analyzed. The survey was carried out in six randomly selected public and private secondary schools in local government areas in Lagos state, Nigeria. A total of 973 students completed self-administered questionnaires on smoking initiation, health related knowledge and attitudes towards smoking, susceptibility to future smoking and other factors associated with smoking. Results: Of the respondents, 9.7% had initiated smoking tobacco products with the predominant form being cigarettes (7.3%). Males (OR: 2.77, 95%CI: 1.65-4.66) and those with more pro-smoking attitudes (OR: 1.44, 95%CI: 1.34-1.54) were more likely to have initiated smoking. Those with parents and friends who are smokers were 3.47 (95%CI: 1.50-8.05) and 2.26 (95%CI: 1.27-4.01) times more likely to have initiated smoking. Non-smoking students, in privately owned schools (OR: 5.08), with friends who smoke (5.09), with lower knowledge (OR: 0.87) and more pro-smoking attitudes (OR 1.13) were more susceptible to future smoking. In addition, respondents who had been sent to purchase cigarettes by an older adult (OR: 3.68) were also more susceptible to future smoking. Conclusions: Being male and having parents who smoke are predictors of smoking initiation among these students. Consistent with findings in other countries, peers not only influence smoking initiation but also influence smoking susceptibility among youth in this African setting. Prevention programs designed to reduce tobacco use among in-school youth should take these factors into consideration. In line with the recommendations of article 16 of the WHO FCTC, efforts to enforce the ban on the sales of cigarettes to minors should be also emphasised.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6451-6455
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• 2015

Background: Primary bone neoplasms are rare, contributing only 0.2% of the global burden of all human malignancies. Osteosarcoma (OS) and chondrosarcoma (CS) are the most common malignancies of bone. The giant cell tumor of bone (GCTb) is a benign tumor with behavior characterized by osteolytic bone destruction. The OS, CS and GCTb affect both sexes, all races and generally have incidence peaks regarding the age of the patient which vary according to the tumor type. We analyzed the incidences of OS, CS and GCTb and their relations with gender and age in patients treated in the National Rehabilitation Institute (INR, for its acronym in Spanish) over a period of nine years. Materials and Methods: In the study period, clinic pathological data for 384 patients were obtained with clinical, radiological and histopathological diagnosis for OS, GCTb and CS. Data analysis was performed using the chi-square and Fisher's exact tests. Results: From 2006 to 2014 were recorded 384 cases of bone malignancies in the database of INR. The GCTb had the highest incidence (53.1%), followed by OS (31.3%) and finally the CS (15.6%). The overall average age was $33.6{\pm}15.8$ years and the overall frequency of gender had a ratio of 1/1.03 male/female. The states with the highest incidence were Distrito Federal and Estado de Mexico with 29.2% and 25.3% respectively. Malignant neoplasms of bone assessed in the course of nine years show three significant increases in 2008, 2011 and 2014 (p=0.14). We found association between sex and tumor type (p=0.03), GCTb and CS predominated in females (54.9% and 56.6% respectively), while for the OS males were most affected (59.1%). Age was different in relation with tumor type (p=0.0001), average age was $24.3{\pm}11.2$ years for OS, $34.5{\pm}13$ years for GCTb and $49.2{\pm}18.5$ years for CS. Furthermore, associations of tumor type with topographic location of the primary tumor (P=0.0001) were found. Conclusions: In this study we can see that incidence of musculoskeletal tumor in our population is continuously increasing and in nine years an approximately 200% increase of musculoskeletal tumor cases was observed.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3341-3355
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• 2016

Background: A recent WHO data report on mortality attributable to tobacco use including cigarette smoking indicated a very high burden of deaths in Asia and that people often initiate smoking as early as young adolescents. The objectives of this study were to systematically review peer-reviewed articles on cigarette smoking initiation among Asian adolescents and to develop a conceptual model of factors influencing smoking initiation by integrating all relevant factors based on existing data. Materials and Methods: Following a PRISMA guideline, a systematic review of articles published between 2005 and June 2015 was conducted using 5 databases on cigarette smoking initiation among adolescents (aged 10-19 years) living in Asia. We summarized the main findings of each study according to our research questions and data that emerged during the data extraction process. Analysis and categorization were based on the TTI and TPB models and classification of factors extracted from the study, were as follows: personal factors, social factors, broader environmental factors, mediators, and intention to initiate smoking and smoking behavior. Results: Of 1,227 identified studies, only 20 were included in this review. Our findings found that the mean age of cigarette smoking initiation ranged from 10 to 14 years and those who are more likely to initiate smoking are male, older adolescents, adolescents with low parental SES, individuals with low parental monitoring, low parental education level and having no discussion on smoking at home, those living in public housing and those exhibiting health-risk behavior. Our study also revealed that the risk of smoking initiation increased when they are exposed to smokers, influenced by peers, exposed to tobacco advertisements, receive pocket money, have lack of knowledge about smoking, have poor school performance, have a family conflict and have psychological problems. The conceptual model developed demonstrated complex networks of factors influencing initiation. Conclusions: This systematic review presents various factors influencing smoking initiation of the Asian adolescents and provides a conceptual framework to further analyze factors. Future studies should have a standard measure of smoking initiation, should analyze interactions and the intensity of relationships between different factors or variables in the conceptual model. This will in turn consolidate the understanding of the different factors affecting smoking initiation and will help to improve interventions in this area.

• Journal of Science and Technology Studies
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• v.15 no.2
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• pp.229-262
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• 2015

Toxic tort cases have increased dramatically since the 1970s, as large technological systems, such as nuclear power plants and chemical factories, or mass-produced, high-tech products, had exposed citizens and consumers to dangerous substances. It was, however, difficult to establish causal connection between exposure and the alleged harms in many of the environmental, pollution, and product liability cases under the framework of tort law conception of causation and responsibility. Science and law was called upon to resolve such 'late modern' legal cases where true causes are hard to find, where no single explanatory factor is sufficient for explaining diseases like cancer. This article examines how plaintiffs in the Korean tobacco litigation mobilized such late modern tools in science and law, such as epidemiology and the allocation of the burden of proof, in the context of the global circulation of science and law. It further shows how a set of the scientific theories and legal arguments developed in order to cope with late modern risk played a central role in establishing a causation between smoking and cancer in 2011. This article suggests that STS scholars can fruitfully examine the interaction between science and law as a way to understand and engage with social and legal issues engendered by late modern risk.

• Journal of Preventive Medicine and Public Health
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• v.57 no.4
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• pp.327-338
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• 2024

Objectives: Estimating the number of deaths caused by smoking is crucial for developing and evaluating tobacco control and smoking cessation policies. This study aimed to determine smoking-attributable mortality (SAM) in Korea in 2020. Methods: Four large-scale cohorts from Korea were analyzed. A Cox proportional-hazards model was used to determine the hazard ratios (HRs) of smoking-related death. By conducting a meta-analysis of these HRs, the pooled HRs of smoking-related death for 41 diseases were estimated. Population-attributable fractions (PAFs) were calculated based on the smoking prevalence for 1995 in conjunction with the pooled HRs. Subsequently, SAM was derived using the PAF and the number of deaths recorded for each disease in 2020. Results: The pooled HR for all-cause mortality attributable to smoking was 1.73 for current men smokers (95% confidence interval [CI], 1.53 to 1.95) and 1.63 for current women smokers (95% CI, 1.37 to 1.94). Smoking accounted for 33.2% of all-cause deaths in men and 4.6% in women. Additionally, it was a factor in 71.8% of men lung cancer deaths and 11.9% of women lung cancer deaths. In 2020, smoking was responsible for 53 930 men deaths and 6283 women deaths, totaling 60 213 deaths. Conclusions: Cigarette smoking was responsible for a significant number of deaths in Korea in 2020. Monitoring the impact and societal burden of smoking is essential for effective tobacco control and harm prevention policies.

• The Journal of Korean Society for Radiation Therapy
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• v.23 no.1
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• pp.21-29
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• 2011

Purpose: The purpose of this master's thesis is to utilize basic data in order to improve the quality of life of cancer patients who received radiation therapy after analysing related factors that influence patient's quality of life and obtaining information about physical, mental problems of patients. Materials and Methods: By using a structured questionnaire about various characteristics and forms of support, I carried out a survey targeting 107 patients that experienced radiation therapy at a university hospital in the Daejeon metropolitan area from July 15 to August 15, 2010 and analysed the factors influencing quality of life. Results: In case of pain due to disease, 65.15 and painless 81.87 showed a high grade quality of life. As body weight decreases, the quality of life become lower. When the grade of quality of life according to economic characteristics was compared, all items except treatment period showed a difference (P=0.000). When the score of social support, family support, medical support and self-esteem was low, the mark of quality of life showed respectively 61.71, 68.77, 71.31, and 69.39 on the basis of 128 points. When the score of support form was high, the mark of quality of life showed 90.47, 83.29, 90.40, and 90.36 (P<0.05). When analyzing the correlation between social support, family support, medical support and self-esteem and the degree of quality of life, social support was 0.768, family support 0.596, medical support 0.434, self-esteem 0.516. They indicated the correlation of meaningful quantity statistically (P<0.01). The factors that improved the quality of life were married state, having a job and painless status. As monthly income increases, the quality of life was also much improved (P<0.05). Among the factors related to quality of life, social support and medical support and higher self-esteem scores of the quality of life score increased 0.979 point, 0.508 points and 1.667 point, respectively. Conclusion: In conclusion, the quality of life of cancer patients that received radiation treatment is related to social support, medical support and self esteem. Self-esteem is an important factor that influenced quality of life, so if government offers works that doesn't affect patient's health, they are a useful method that maximize self-esteem and lessen their financial burden at the same time. Along with these policies, the developments of the attention of medical and the program for cancer patient's family are needed for the purpose of improving quality of life of cancer patients. Lastly, medical team, patients and family have to cooperate in harmony to overcome difficulties of cancer patients.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.34-40
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• 2021

Purpose If a new test is introduced or reagents are changed in the laboratory of a medical institution, the characteristics of the test should be analyzed according to the procedure and the assessment of reagents should be made. However, several necessary conditions must be met to perform all required comparative evaluations, first enough samples should be prepared for each test, and secondly, various reagents applicable to the comparative evaluations must be supplied. Even if enough comparative evaluations have been done, there is a limit to the fact that the data variation for the new reagent represents the overall patient data variation, The fact puts a burden on the laboratory to the change the reagent. Due to these various difficulties, reagent changes in the laboratory are limited. In order to introduce a competitive bid, the institute conducted a full investigation of Radioimmunoassay(RIA) reagents for each test and established the range of reagents available in the laboratory through comparative evaluations. We wanted to share this process. Materials and Methods There are 20 items of tests conducted in our laboratory except for consignment tests. For each test, RIA reagents that can be used were fully investigated with the reference to external quality control report. and the manuals for each reagent were obtained. Each reagent was checked for the manual to check the test method, Incubation time, sample volume needed for the test. After that, the primary selection was made according to whether it was available in this laboratory. The primary selected reagents were supplied with 2kits based on 100tests, and the data correlation test, sensitivity measurement, recovery rate measurement, and dilution test were conducted. The secondary selection was performed according to the results of the comparative evaluation. The reagents that passed the primary and secondary selections were submitted to the competitive bidding list. In the case of reagent is designated as a singular, we submitted a explanatory statement with the data obtained during the primary and secondary selection processes. Results Excluded from the primary selection was the case where TAT was expected to be delayed at the moment, and it was impossible to apply to our equipment due to the large volume of reagents used during the test. In the primary selection, there were five items which only one reagent was available.(squamous cell carcinoma Ag(SCC Ag), β-human chorionic gonadotropin(β-HCG), vitamin B12, folate, free testosterone), two reagents were available(CA19-9, CA125, CA72-4, ferritin, thyroglobulin antibody(TG Ab), microsomal antibody(Mic Ab), thyroid stimulating hormone-receptor-antibody(TSH-R-Ab), calcitonin), three reagents were available (triiodothyronine(T3), Tree T3, Free T4, TSH, intact parathyroid hormone(intact PTH)) and four reagents were available are carcinoembryonic antigen(CEA), TG. In the secondary selection, there were eight items which only one reagent was available.(ferritin, TG, CA19-9, SCC, β-HCG, vitaminB12, folate, free testosterone), two reagents were available(TG Ab, Mic Ab, TSH-R-Ab, CA125, CA72-4, intact PTH, calcitonin), three reagents were available(T3, Tree T3, Free T4, TSH, CEA). Reasons excluded from the secondary selection were the lack of reagent supply for comparative evaluations, the problems with data reproducibility, and the inability to accept data variations. The most problematic part of comparative evaluations was sample collection. It didn't matter if the number of samples requested was large and the capacity needed for the test was small. It was difficult to collect various concentration samples in the case of a small number of tests(100 cases per month or less), and it was difficult to conduct a recovery rate test in the case of a relatively large volume of samples required for a single test(more than 100 uL). In addition, the lack of dilution solution or standard zero material for sensitivity measurement or dilution tests was one of the problems. Conclusion Comparative evaluation for changing test reagents require appropriate preparation time to collect diverse and sufficient samples. In addition, setting the total sample volume and reagent volume range required for comparative evaluations, depending on the sample volume and reagent volume required for one test, will reduce the burden of sample collection and planning for each comparative evaluation.