Türkiye’de üstyapı projelerinde zaman-maliyet ilişkileri

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Proje öncesi safhalarda henüz çok az proje değişkeni biliniyorken inşaat projelerinin sözleşme sürelerini ve nakit akışlarını tahmin etmek oldukça önemli ve bir o kadar da zor bir konudur. Diğer taraftan, projelerin ilk safhalarında gerçekleştirilen tahminler, devam eden süreçte bütçe, nakit akışı, iş programı gibi konuların belirlenmesinde referans oluşturmaktadır. Bu bağlamda, inşaat projelerinde proje öncesi safhalarda süre-maliyet ilişkisinin ortaya konulması gerek bilim insanları gerekse inşaat firmaları ve yatırımcılar açısından önemli bir çalışma alanı olmuştur. Bu çalışmada Türkiye'deki üstyapı projelerinin süre-maliyet ilişkisi araştırmıştır. Çalışma kapsamında Türkiye' de 1999-2018 yılları arasında 65 farklı inşaat firması tarafından tamamlanmış 501 adet üstyapı projesinin süre ve maliyet verileri kullanılmıştır. Veriler öncelikle yapıların kullanım amaçlarına göre gruplandırılmış (tekil bina, okul, hastane, sanayi ve TOKİ sosyal konut ve TOKİ afet Konut) ve daha sonra her grup için ayrı ayrı süre-maliyet ilişkileri belirlenmiştir. Ayrıca dış faktör olarak, döviz kurları, çalışılamayan gün sayısı, insani gelişmişlik endeksi ve gayri safi yurtiçi hasıla gibi önceki çalışmalarda araştırılmamış parametrelerin üstyapı projelerinin süre-maliyet ilişkisi üzerindeki etkileri istatiksel olarak araştırılarak bu alandaki bilimsel boşluğun doldurulması hedeflenmiştir. Çalışmanın ilk safhalarında, üstyapı projelerinin süre-maliyet ilişkileri, Bromilow zaman maliyet modeli (BTC) ve S-Eğrileri ile projeler bazında ayrı ayrı araştırılmıştır. Devam eden bölümlerde proje öncesi safhalarda üstyapı inşaat projelerinin tamamlanma sürelerinin ve nakit akışlarının tahmini için Yapay Sinir Ağları yöntemi ile bütünleşik bir karar destek sistemi oluşturulmuş ve model sonuçları, ilk aşamada elde edilen sonuçlar ile karşılaştırılmıştır. Araştırma sonuçları değerlendirildiğinde önerilen bütünleşik modelin; Türkiye'deki üstyapı projelerinin süre-maliyet ilişkisi ve nakit akışı yönetimi açısından daha anlamlı ve hassas sonuçlar verdiği tespit edilmiştir. Çalışma kapsamında gerçekleştirilen analizlerde Yapay Sinir Ağları ile önerilen modelin projelerin tamamlanma sürelerini; %13.55, S-Eğrilerini %10,83 hata (RMSE) ile tahmin edebildiği tespit edilmiştir. Diğer taraftan, YSA modelinin doğrulama testleri sonucunda; BTC modeline göre %11,57 oranında gerçek değerlere daha yakın tahminlerde bulunduğu, YSA nakit akışı eğrilerinin de polinomial regresyon ile oluşturulan eğrilere kıyasla gerçek S-Eğrilerine daha iyi uyum sağladığı ve nakit akışlarında gerçekleşebilecek dalgalanmaları hassas bir şekilde tahmin edebildiği tespit edilmiştir. Çalışma sonucunda Türk inşaat sektöründe faaliyet gösteren yatırımcı, yüklenici firmalar ile proje yönetim ekiplerinin ihale öncesi safhalarda ve proje süresince ek bir çaba sarf etmeden istifade edebileceği; projelerin tamamlanma sürelerini ve nakit akışlarını tahmin edebilen alternatif bir karar destek sistemi önerilmiştir.Estimating the duration and cash flows of construction projects is an extremely important and challenging issue in the pre-project phases when there are still unknown many variables. On the other hand, estimates carried out in the early stages of the projects, create references for budget planning, cash flow, and work Schedule in the on-going phases of the projects. In this context, estimating the time-cost relationship in the pre-project phases of construction projects is a significant research area for both academicians, construction companies and investors. In this study, the time-cost relationship of the superstructure projects in Turkey was investigated. Time and cost data of 501 superstructure projects, completed by 65 construction companies between 1999-2018 in Turkey. Firstly, gathered data grouped into type of projects (singular building, school, hospital, industry and TOKI, social housing and TOKI disaster housing), then for every group seperate time-cost relationship was determined. It was aimed to fill the gap in the literature with investigating the effect of external factor such as exchange rates, non-working days, human development index and gross domestic product, on time and cost relationship superstructure projects statistically. In the first stages of the study, the time-cost relationships of the superstructure projects were investigated with Bromilow time cost model (BTC) and S-Curves separately on the project basis. In the following sections, an integrated decision support system with Artificial Neural Networks (ANN) method has been established to estimate the realization time and cash flow in the pre-project phases and the model results have been compared with the results obtained in the first stage. When the results of the research are evaluated, it has been determined that the proposed integrated model has been found to give a more meaningful and accurate results for time-cost relationship of the superstructure projects in Turkey. As a result of the analyzes, it was found that the proposed model with ANN can estimate the completion times of the projects with 13.55% error and S-Curves with 10.83% error (RMSE). On the other hand, as a result of validation tests, it has been determined that ANN model predicts closer to real values by 11.57% compared to BTC model, and ANN cash flow curves provide better adaptation to real S-Curves than polynomial regression curves and the ANN model can estimate possible fluctuations that may occur in cash flows more sensitively. As a result of the study, it has been proposed an alternative decision support system model, which can estimate the completion times and cash flows of projects, for the use of investors, contractors and project management teams operating in the Turkish construction sector during pre-tender stages without any additional effort

Which Micro-Organisms are Transferred by Healthcare Personnel Between Hospital and Home?

Introduction: The most important factor in the spread of hospital infections is the hands of healthcare personnel. The aim of ths study was to determine which micro-organisms are transferred from home to hospital, and which from hospital to home, by the hands of healthcare personnel. Material and Methods: The sample universe of this research was the healthcare personnel in a tertiary level public hospital. A total of 10 doctors and 53 nurses, selected at random according to the clinics where they worked, were included. The study data were collected in two stages. In the first stage, the study participants completed a personal information form. In the second stage, samples were taken from the right and left hands of the healthcare personnel on entering and leaving the hospital. The samples were isolated and seeded in culture media. Bacteria identification and antibiotic sensitivity were determined using a BD Phoenix 100 automated system. Results: According to the samples taken, there was determined to be greater bacteria production on the hands of the healthcare personnel when entering the hospital. The greatest production was in the least washed area of the right hand (93.7% on entry, 74.6% on exit). Nurses and those working in surgical clinics were seen to have greater bacteria production on both entry to and exit from the hospital compared to other healthcare workers. The bacteria most produced were MSSE, Micrococcus, Staphylococcus strains, Streptococcus strains and MRSE. In the examination of antibiotic sensitivity, the antibiotics to which the produced bacteria were most sensitive were amikacin, ciprofloxacin, daptomycin, gentamicin levoflaxocin, teicoplanin, linezolid teicoplanin, trimetoprim/sulfamethoxazole and vancomycin. Conclusion: The study results showed that just as healthcare personnel transferred some micro-organisms from home to hospital on their hands, they also transferred some bacteria to home on leaving the hospital. This is of great importance in respect of the spread of hospital infections. With the necessary precautions taken to prevent the transfer of micro-organisms to or from hospital, the prevalence of hospital infections will decrease. Keywords: Healthcare personnel, Micro-organisms, Antibiotic resistance, Hand DOI: 10.7176/JHMN/110-04 Publication date:August 31st 202

CICMalDroid2020 Veri Kümesi Kullanılarak Kötü Amaçlı Yazılım Tespiti için Makine Öğrenimi Algoritmalarının Performans Analizi

Teknolojideki gelişmelere paralel olarak bilgiye erişim kolaylaşmıştır. Bu durumun hayatımıza pozitif etkisi olsa da bilginin hedef haline geldiği kaçınılmaz bir gerçektir. Kötü amaçlı kişiler tarafından bilgilerin çalınması, tehdit unsuru olarak kullanılması bilgi güvenliği konusunda endişelere sebep olmuştur. Bu amaçlarla geliştirilen kötücül yazılımlar, bilginin güvenliği açısından büyük bir tehlike oluşturmaktadır. Bilgiye erişim kolaylaştıkça artan bu durum karşısında araştırmacılar, kötücül yazılımların tespiti, engellenmesi ve bilgi güvenliğinin sağlanması konusunda çalışmalarına hız kazandırmışlardır. Literatürde, farklı çalışmalar ile kötücül yazılımların tespiti gerçekleştirildiği görülmektedir. Bu çalışmada ise, kötücül yazılım tespiti WEKA programı kullanarak gerçekleştirilmiştir. CICMalDroid2020 veri seti ile yapılan analizlerde, farklı makine öğrenmesi sınıflandırıcılarının, özellik çıkarımının ve en iyi sonucu veren sınıflandırmanın performansını etkileyen parametrelerin etkisi incelenmiştir. Sonuçlar, detaylı bir şekilde aktarılmıştır

The effects of taxifolin on neuropathy related with hyperglycemia and neuropathic pain in rats: A biochemical and histopathological evaluation

Background. Hyperglycemia can be considered a determining factor in the development of diabetic neuropathy as well as neuropathic pain. There is a relationship between the excessive production of reactive oxygen species (ROS) and the pathogenesis of diabetic neuropathic pain. Taxifolin, on the other hand, is a flavonoid that has been documented to inhibit ROS production. Objectives. To investigate the effects of taxifolin, which has antioxidant and neuroprotective effects, on alloxan-induced hyperglycemia-induced neuropathy and neuropathic pain, biochemically and histopathologically. Materials and methods. The albino Wistar male rats were divided into 3 groups: Healthy group (HG), only alloxan group (AXG) and alloxan+taxifolin group (ATG). Hyperglycemia in animals was caused through intraperitoneal injection of alloxan at a dose of 120 mg/kg. Paw pain thresholds of animals were measured using Basile algesimeter. Sciatic nerve tissues were examined biochemically and histopathologically in order to evaluate neuropathy. Results. Our experimental results revealed that taxifolin significantly prevented the increase of plasma glucose concentration level with alloxan administration, the decrease of the paw pain threshold related to hyperglycemia, the change of oxidant-antioxidant balance in the sciatic nerve tissue in favor of oxidants, and the deterioration of tissue morphology in animals. Conclusions. Our experimental results indicate that taxifolin alleviates alloxan-induced hyperglycemia-related neuropathy and neuropathic pain

Ultrasonographically detected hepatosteatosis independently predicts the presence and severity of coronary artery disease

Objectives: The aim of our study was to evaluate the association between the presence and severity of CAD and NAFLD. Methods: The study group consisted of 153 patients who underwent coronary angiographies. Patients were categorized into CAD and non-CAD groups. CAD severity was determined by the number of CAD-involved arteries and the vessel score multiplied by Gensini score, the latter judging CAD severity. Fatty liver was diagnosed by abdominal ultrasonography (USG), with the patients being categorized by the degree of hepatosteatosis, as Grade 0, Grade 1, and Grade 2-3. Results: Among the whole study population, 47.1% of patients (n=72) were female and 52.9% of patients (n=81) were male. Forty-three patients had normal coronary arteries; 27 patients had non-critical CAD and side branch disease; and 83 patients had clinically significant CAD (stenosis>50%). The rate of CAD and Gensini score were significantly different between Grade 0, 1 and 2-3 hepatosteatosis groups (p<0.05). Patients with CAD had a significantly higher AST level than those without (p< 0.05). Conclusion: Ultrasonographically detected hepatosteatosis independently predicts the presence and severity of CAD. Keywords: Nonalcoholic fatty liver disease; gensini score; obesity

Regional Analysis of Inner Retinal Layer Changes in Multiple Sclerosis with and without Optic Neuritis

Objectives:The study aimed to investigate inner retinal changes in multiple sclerosis (MS) patients by comparing them with healthy controls. The study also aimed to assess regional differences of inner retinal layer involvement in eyes with and without optic neuritis (ON).Materials and Methods:This retrospective, cross-sectional study consisted of 141 eyes of 74 relapsing-remitting MS patients and 80 eyes of 40 healthy controls. The study group was separated into two subgroups according to the presence of ON history. Peripapillary retinal nerve fiber layer (pRNFL) thickness, total macular thickness, and thicknesses of the macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer were compared between the MS and healthy control groups and between eyes with and without ON history.Results:Mean pRNFL, total macular, mRNFL, GCL, and IPL thicknesses were significantly thinner in the MS group than in the control group (p<0.001) and in eyes with ON compared to those without ON (p<0.05). Comparison of inner retinal layer thicknesses in the inner 3-mm ring subfields of the ETDRS grid revealed significant thinning in all subfields of the GCL and IPL of eyes with ON (p<0.05). The inferior subfield demonstrated the highest difference.Conclusion:The study demonstrated that GCL and IPL thinning is a robust and reliable biomarker in all MS patients. The thinning was significantly greater in eyes with ON than in eyes without ON. The study also documented that the inferior region showed significantly greater GCL and IPL thinning in eyes with previous ON attacks

Flow diverter as a rescue therapy for a complicated basilar angioplasty

Intracranial atherosclerotic disease is a major cause of ischemic stroke. Stenting and aggressive medical management for preventing recurrent stroke in intracranial stenosis was terminated prematurely due to a high stroke and death rate in patients randomized for intracranial stent placement. However, for some patients, angioplasty and/or stent placement remains the best approach. Flow diverters (FDs) are designed to produce a hemodynamic flow diversion by constituting a laminar flow pattern in the parent artery and are mainly used in non-ruptured complex wide-neck aneurysms as well as in ruptured aneurysms. Herein, we present a case where an FD was used in a complicated angioplasty for basilar artery atherosclerosis. A 72-year-old female patient was admitted to our hospital with left side weakness and vertigo. Her diffusion magnetic resonance imaging and magnetic resonance angiography showed right-sided pontine and left-sided occipital acute infarcts with left-sided pontine and right-sided occipital chronic infarcted areas and preocclusive mid-basilar stenosis. The patient was under supervised medical treatment. Despite chronic brain stem and occipital infarcts her modified Rankin Scale was 2. Diagnostic angiography showed no posterior communicating arteries and no pial-pial collaterals and a critical mid-basilar artery stenosis. We decided to perform intracranial angioplasty to increase the perfusion of posterior circulation and reduce the risk of additional embolic infarcts. Angioplasty was complicated with dissection and vessel perforation. We used an FD for rescue therapy to avoid rebleeding. The patient was discharged with good clinical and angiographic results

Management of priapism: Results of a nationwide survey and comparison with international guidelines

Objective: The aim of this study is to evaluate current urologic practice regarding the management of priapism in Turkey and compare with international guidelines. Methods: Urologists and urology residents were invited to an online survey consisting of 30 multiple-choice questions on priapism-related clinical practices that were considered most important and relevant to practices by using Google Forms. Results: Total number of responses was 340. Respondents reported that they recorded a detailed patient’s medical history and physical examination findings (n = 340, 100%) and laboratory testing, which includes corporal blood gas analysis (n = 323, 95%). Participants announced that they performed Doppler ultrasound for 1/4 cases (n = 106, 31%), but 22% of the participants (n = 75) replied that they performed in >75% of cases. Participants (n = 311, 91%) responded that the first-line treatment of ischemic priapism is decompression of the corpus cavernosum. Moreover, most respondents (n = 320, 94%) stated that sympathomimetic injection drugs should be applied as the second step. About three-quarters of respondents (n = 247, 73%) indicated adrenaline as their drug of choice. Phosphodiesterase type 5 inhibitors seems to be the most preferred drug for stuttering priapism (n = 141, 41%). Participants (n = 284, 84%) replied that corpora-glanular shunts should be preferred as the first. A large number of participants (n = 239, 70%) declared that magnetic resonance imaging can be performed in cases with delayed (>24 hours) priapism to diagnose corporal necrosis. Most of the participants (84%) responded that penile prosthesis should be preferred to shunts in cases with delayed (>48 hours) priapism. Conclusion: It would be appropriate to improve the training offered by professional associations and to give more training time to the management of priapism during residency

Evaluation of self-esteem and dermatological quality of life in adolescents with atopic dermatitis

Background and Design: Atopic dermatitis is a chronic, inflammatory skin disease characterized by itchy skin lesions. Since adolescents are intensely interested in their physical appearance, chronic skin diseases in this period can adversely affect the development of self esteem. Atopic dermatitis is a skin disease that affects the appearance and there is an heightened attention to the body image in adolescence which is an important period of time in the development of self-esteem. Therefore, we aimed to investigate self-esteem and dermatological quality of life in adolescents with atopic dermatitis. Materials and Methods: Thirty-three patients with atopic dermatitis and 33 healthy controls were included in the study. The Piers-Harris Children’s Self-Concept Scale and the Children’s Dermatology Life Quality Index (CDLQI) were used for determining self-esteem and quality of life. The Scoring of Atopic Dermatitis (SCORAD) Index was used to assess the severity of atopic dermatitis. Results: It was found that patient group had lower self-esteem than healthy controls according to the Piers-Harris Children’s Self-Concept Scale. A statistically significant difference was observed in happiness/satisfaction and anxiety subscale scores between the patients and healthy controls while there was no significant difference between the other sub-scale scores. Mean value of dermatological quality of life in patients with atopic dermatitis was significantly lower than in healthy controls. A moderate negative correlation was found between self-esteem and CDLQI scores among adolescents with atopic dermatitis. Discussion: This study results have shown that self-esteem and dermatological quality of life were adversely affected in adolescents with atopic dermatitis irrespective of gender. These patients should be examined psychiatrically besides dermatological examination and treatment. We suggest that improvement will be observed in self-esteem and quality of life of adolescents with atopic dermatitis by providing the necessary psychosocial support