A simulation-based decision support tool for economical materials management system in the construction industry

Bir yüklenici inşaat firması, projenin en başında, bolluk miktarı (büyük, orta veya küçük), planlama yaklaşımı (iyimser, nötr veya kötümser) ve parti hacmine (büyük veya küçük) bağlı olarak değişen 18 değişik malzeme yönetim alternatifinden birini seçebilir. Bu araştırmada, yüklenici inşaat firmalarına, en düşük toplam envanter maliyetini oluşturacak olan bolluk miktarını, planlama yaklaşımını ve parti hacmini tavsiye edecek simulasyon tabanlı karar destek modeli geliştirilmiş ve bu model yardımı ile tamamlanmış olan üç ticaret merkezi projesinden elde edilen veriler kullanılarak sözkonusu malzeme yönetim sistem alternatifleri için toplam envanter maliyeti hesaplanmıştır. İncelenen projelerde, geliştirilen modelin uygulanması, yüklenici inşaat firmalarına %4.2-7.3’lük bir maliyet kazancı sağlamıştır.  Anahtar Kelimeler: Malzeme yönetimi, tam zamanında yönetim, simulasyon modeli.   Materials constitute a large proportion of the total cost of construction. Proper management of the material flow may play a significant role in enhancing the effectiveness of a contractor. The generally acknowledged rules of materials management are small orders, frequent deliveries, and reduced inventory. A contractor should be familiar with the impacts of lot size (large or small) and buffer size (large, medium or small) as governed by contractor's scheduling practice (optimistic, neutral or pessimistic) in handling uncertainty and variability on the economics of the each material management alternative at the beginning of the project in order to make a decision on the most economical alternative that will be used throughout the project. The main objective of this study is to provide contractors with an objective and dynamic tool, namely a discrete event simulation model, to assist them in selecting the most economical materials management system by recommending buffer sizes, a scheduling practice, and lot sizes given the special conditions of the project at the beginning of the project. After the simulation-based decision support tool was completed, it was time to plug the actual data obtained from the completed three trade center projects into the simulation model and run the model. The case studies revealed that using the simulation-based decision support tool provided the contractor with a cost saving of 4.2-7.3% in the studied projects. Keywords: Materials management, just-in-time management, simulation modeling. 

Kriminoloji araştırmalarında mağdur anketlerinin yeri ve önemi

Due to increasing crime rates, insufficient policies and the limitations of the official statistics, victim surveys are being used as an alternative crime measurement technique. These types of surveys are inspired most of the criminological theories and regarded as a data source especially in shaping the crime policies of the Anglo-Saxon countries. Even though they have developed over time, victim surveys have limitations which create an obstacle in measuring crime. However, these surveys could be used as a useful data source in analyzing victims, their needs and behaviors. The recent victim surveys, which were conducted in Turkey, revealed significant findings. In the future, it is inevitable to use victim surveys as a management instrument in the field of security policies in Turkey. This study first examines the birth and development of the victim surveys, then it discusses the theoretical and methodological problems and the victim surveys conducted in Turkey. In conclusion section, this article provides recommendations related to the topic.Suç oranlarındaki artış, suç politikalarının yetersizliği ve resmi istatistiklerin sınırlılıkları alternatif bir suç ölçme tekniği olan mağdur anketlerinin doğmasına neden olmuştur. Bu tür anketler, birçok suç teorisine ilham vermiş ve özellikle Anglo-Sakson ülkelerinde suç politikalarında başvurulan bir veri kaynağı haline gelmiştir. Fakat zaman içerisinde gelişim göstermiş olsalar da, mağdur anketleri bünyesinde birçok metodolojik sınırlılığı barındırmakta ve bu sınırlılıklar, anketlerin suçun ölçümünde kullanılmasını engellemektedir. Buna karşılık bu anketler, mağdurlar, mağdurların beklentileri ve mağdurların davranışlarının etüdü konusunda faydalı bir veri kaynağı olabilir. Son yıllarda Türkiye’de yapılan mağdur anketleri çarpıcı sonuçlar ortaya çıkarmıştır. Mağdur anketlerinin, önümüzdeki yıllarda Türk kamu güvenlik politikalarında bir yönetim enstrümanı olarak kullanılması kaçınılmazdır. Bu çalışmada, ilk olarak, mağdur anketlerinin ortaya çıkışı ve gelişimi, ardından karşılaşılan teorik ve metodolojik problemler ve Türkiye’de yapılan mağdur anketleri ele alınmış, sonuç bölümünde ise konuya ilişkin bazı önerilerde bulunulmuştur

Effect of disease acceptance in geriatric individuals on life satisfaction

Introduction: Elderly must maintain regular care and complex treatment of several chronic diseases that develop with age or that pre-exist. Having a chronic disease entail both a feeling of loss and the need to keep the disease and one’s life under control. It is important for these individuals to accept their illness while maintaining treatment and care. Life satisfaction, on the other hand, is the result of comparing what a person has with his or her expectations. This analytical cross-sectional study was conducted to examine the effect of disease acceptance on the life satisfaction of geriatric individuals. Methods: The research type is analytical cross-sectional study. The research was conducted between February 1-July 31, 2019 in a hospital in Izmir, in Türkiye. A total of 140 individuals over the age of 65 were included. A sociodemographic questionnaire, the Disease Acceptance Scale, and the Life Satisfaction Scale were used as data collection tools. Results: The mean disease acceptance score of the elderly individuals was 25.95 ± 5.25, and the life satisfaction score was 20.39 ± 5.94. Cardiology, endocrinology, dermatology, and gastroenterology patients evaluated their health as good, while individuals with respiratory system diseases evaluated their health as bad. A significant relationship was also found between marital status, disease type, health assessment status, and life satisfaction. While the life satisfaction of married individuals was borderline significant, it was determined that the life satisfaction of individuals with respiratory problems and poor health status was low. When the scores of the two scales were compared, a moderate positive correlation was found. Conclusion: There is a strong correlation between the acceptance of illness and life satisfaction of elderly individuals. When older individuals accept their illness, their life satisfaction also increases. When older individuals accept their illness, their life satisfaction also increases. Socioeconomic status of elderly individuals and having more than one disease play an active role in accepting the disease and life satisfaction. The importance of accepting the disease should be considered in order to increase life satisfaction. Keywords: Aging, elderly, satisfactio

The effect of 3-methylcholanthrene and butylated hydroxytoluene on glycogen levels of liver, muscle, testis, and tumor tissues of rats

This study examined the effects of separate and combined applications of 3-methylcholanthrene, a polycyclic aromatic hydrocarbon and potent carcinogenic agent, and butylated hydroxytoluene, the antioxidant food additive, on the glycogen levels of liver, muscle, testis, and tumor tissues in rats. Adult male Wistar albino rats weighing 100-110 g at 8 weeks of age were used in this study. This study consisted of a control group (n = 9) and 3 different experiment groups in which rats were chronically treated with 3-methylcholanthrene (n = 9) or butylated hydroxytoluene (n = 11) or a combination of these agents (n = 14). Rats were intraperitoneally injected with a 200 mg kg(-1) dose of butylated hydroxytoluene and a 40 mg kg-1 dose of 3-methylcholanthrene. At the end of the 26-week experimental period, tissues of rats killed via cervical dislocation were placed in 10% trichloroacetic acid for glycogen determination. Our results showed that the administration of 3-methylcholanthrene, butylated hydroxytoluene, and 3-methylcholanthrene + butylated hydroxytoluene caused statistically significant changes in the glycogen levels of liver, muscle, and testis tissues, and glycogen was stored in tumor tissue

Kikuchi fujimoto disease: a case report

Kikuchi-Fujimoto hastalığı veya histiyositik nekrotizan lenfadenit (HNL) özellikle ortalama 30 yas civarındaki bayanlarda görülen kendiliğinden sınırlanan, nekrotizan servikal lenfadenopati ile karakterize bir hastalıktır. Ates, titreme, kas ve eklem ağrısı, splenomegali ve deride döküntüleri kliniğe eşlik edebilir. Hastalık bir-üç ay içinde kendiliğinden düzelir.Asya'da daha yaygın olmakla beraber bütün dünyada görülebilir. Yirmi yasında, servikal lenfadenopati ve ateş şikayeti olan, eksizyonel lenf nodu biyopsisinde ve patolojik Değerlendirilmesinde HNL tanısı konulan bir erkek hasta sunuldu. HNL hastalığı benin lenfadenopatinin nadir nedenlerinden biridir. Benign, etyolojisi bilinmeyen bu hastalık yaygın olarak lenfoma yanlış tanısını alır. Kendiliğinden sınırlanan bu klinik tablo benign lenfadenopatilerin ayırıcı tanısında gözardı edilmemelidir.Kikuchi-Fujimoto disease or Histiocytic necrotizing lymphadenitis (HNL) is a self-limited disorder characterized by necrotizing cervical lymphadenopathy in especially women (with a mean age of 30 years). It presents with fever, chills, myalgias, arthralgias, splenomegaly, and skin rashes. The disease usually resolves within 1-3 months. It is most common inAsia but has been described worldwide. We present a 20 years old man with complaints of cervical lymphadenopathy and fever, whom diagnosed as Kikuchi-Fujimoto disease with excisional lymph node biopsy and pathological inspection. HNLdisease is one of the rarest causes of benign lymphadenopathy. This disease, whose etiology is not known, is commonly misdiagnosed as lymphoma. This self-limiting disease should be kept in mind in differential diagnosis of benign lymphadenopathies

Turner syndrome and associated problems in turkish children: A multicenter study

Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology

Ecological investigations on Hydrophilidae and Helophoridae (Coleoptera) specimens gathered from several water bodies of Western Turkey

The aim of this study is to present environmental variables which were effective on habitat preferences of Hydrophilidae and Helophoridae species found in western region of Turkey. The surveys were conducted in İzmir, Manisa and Aydın provinces and specimens were collected regularly during the years 2013 and 2014. Totally, 30 species classified in 8 genera of the two families were recorded. Physicochemical parameters including temperature, dissolved oxygen, pH, electrical conductivity and salinity were measured from 99 different aquatic sites. The relationships between the species and the effect(s) of the mentioned parameters on the presence or absence of the beetles were evaluated by various statistical tests. According to the results; electrical conductivity, salinity and temperature are the main water parameters associated with aquatic beetle distribution. Pearson's correlation analysis coefficient between the salinity and electrical conductivity parameters was calculated as 0.965 which is statistically significant (p < 0.01). The relationships between environmental variables and the determined species were also evaluated with canonical correspondence analysis (CCA), and the distributions of species according to these variables were presented by using a CCA plot

Evaluation Of Contractor Firms’ Bidding And Cost Management Systems

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1999Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 1999Bu çalışmada, Türk inşaat sektöründe faaliyet gösteren yüklenici firmalarda uygulanmakta olan teklif hazırlama ve maliyet yönetimi sistemleri irdelenerek konuyla ilgili olarak yapılan kapsamlı literatür çalışmasından elde edilen bilgilere göre değerlendirilmiş ve karşılaşılan sorunlar saptanarak bunları iyilemeye yönelik çözüm önerileri getirilmiştir. Yüklenici inşaat firmalarının teklif hazırlama ve maliyet yönetimi sistemleri değerlendirilirken, uygulamada karşılaşılaşılan sorunlar da gözönüne alınmış olup bunlar; inşaat sektörünün özelliklerinden, ihale sisteminden kaynaklanan, finansal, firma bazında karşılaşılan sorunlar olmak üzere sınıflandırılmıştır. Planlama kavramı; maliyet, süre ve kaynak planlamasından oluşan bir bütündür. Planlama, büyük bir düzensizlik ve belirsizlik içinde bulunan ülkemiz ve inşaat sektörümüz için henüz çok yeni olan ve önemi yavaş yavaş anlaşılmaya başlanan bir kavramdır. Bazı firmalar, bu konuda oldukça duyarlı ve yenilikçi yaklaşımlar sergileyerek, kendilerini geliştirme ve değiştirme sürecine girmişlerdir. Zaman içinde, bu kavramın ve bu kavramla beraber gelen düzen ve sistemin, artan rekabet koşulları karşısında, sektörde faaliyet gösteren tüm firmalarda yaygınlaşacağı ve oturacağı kesindir.In this study, the bidding and cost management systems performed in the Turkish contractor construction firms are examined and these systems are evaluated on the basis of the literature study upon the subject. From these findings the problems encountered are detected and solutions to optimise these problems are suggested. In evaluation process of the bidding and cost management systems of the construction contractor firms, problems encountered in real life are considered; these problems are classified as the problems emanates from the awarding system in Turkey, peculiarity of the construction sector and financial, firm scaled problems. Planning is a concept that is very new and which importance has just understood in our country and construction industry in disorder and instability. Some firms, about this subject, exhibits very sensitive and innovative approach and have begun to an era of developing and changing themselves. As time goes, under the conditions of hard competition, it is certain that this concept and the order and system coming from the concept will spread in the firms in construction industry.Yüksek LisansM.Sc