Browsing by Author "Tan, T."
Now showing 1 - 13 of 13
- Results Per Page
- Sort Options
Item Open Access Anayasa Mahkemesi kararlarında kamu hizmeti yaklaşımı(Doğan Burda Rizzoli Dergi Yayıncılık, 2010) Tan, T.Item Open Access Anayasa Mahkemesi uygulamalarına ilişkin bazı gözlemler: Prof. Dr. Köksal Bayraktar'a armağan(Galatasaray Üniversitesi, 2010) Tan, T.Anayasa Mahkemesi’nin bugüne dek uygulamalarına baktığımızda, özellikle mahkemelerden itiraz yolu ile gelen Anayasa’ya aykırılık savlarını içeren dosyaları esastan incelemeye geçmeden önce, başvuranın “bir davaya bakmakta olan mahkeme” niteliğinde olup olmadığını incelemektedir. Bu incelemesini yaparken mahkemenin olup olmadığını araştırdığı gibi; davacının dava ehliyetine sahip olup olmadığını da incelemektedir. Bu yazıda ilk olarak bu konuyu ele alacağız. İkinci olarak da, Anayasa’nın (m.153) iptal kararlarının gerekçesi yazılmadan açıklanamayacağını, kararların Resmi Gazete’de hemen yayımlanacağını ve iptal edilen yasa, KHK ve İçtüzük hükümlerinin kararın Resmi Gazete’de yayımlandığı tarihte yürürlükten kalkacağını öngörmesine karşın, uygulamada iptal kararlarının gerekçeleri yazılmadan ve Resmi Gazete’de yayımlanmadan açıklanması ve bu uygulamanın söz konusu yasa maddelerinin uygulandığı davalara bakmakta olan mahkemelerde yarattığı duraksama üzerinde duracağız.Item Open Access Anayasa Mahkemesi'nin yerel idarelere bakışı(D B R - Dogan Burda Rizzoli, 2010) Tan, T.Item Open Access Bağımsız idari otoriteler veya düzenleyici kurullar(Türkiye ve Orta Doğu Amme İdaresi Enstitüsü, 2002) Tan, T."Bağımsız idari otorite" veya "düzenleyici kurul" kavramları Türk kamu yönetiminde yeni bir yapılanmayı simgelemektedir. Bu yeni yapılanma yalnız idare hukuku ve yönetim bilimi öğretisinde değil, özellikle yasama-yürütme-yargı erklerinin ilişkisi açısından, siyaset bilimi ve anayasa hukuku öğretisinde de inceleme konusudur. Bu kuruluşların ilk örnekleri anglo-sakson sisteminde görülmektedir. Ancak, Kara Avrupası ülkelerinde bu yeni yapılanmanın benimsenmesi, anayasal düzenlemelerden kaynaklanan ciddi bir muhalefetle karşılaşmaktadır. Duzenleyici kurulların Türk kamu yönetimi içindeki yerinin belirlenmesi onların yapısal ve işlevsel özelliklerinin açıklığa kavuşturulmasını ve klasik kamu kurumlarındanfarklarının ortaya konulmasını gerektirmektedir. Bunun için de bu kuruluşların kurumsal özerlikleri yanında düzenleme, denetleme, yaptırım uygulama ve uyuşmazlık çözme işlevleri incelenmektedir.Item Open Access An integrated approach to inventory and flexible capacity management subject to fixed costs and non-stationary stochastic demand(Springer, 2009) Tan, T.; Alp O.In a manufacturing system with flexible capacity, inventory management can be coupled with capacity management in order to handle fluctuations in demand more effectively. Typical examples include the effective use of temporary workforce and overtime production. In this paper, we discuss an integrated model for inventory and flexible capacity management under non-stationary stochastic demand with the possibility of positive fixed costs, both for initiating production and for using contingent capacity. We analyze the characteristics of the optimal policies for the integrated problem. We also evaluate the value of utilizing flexible capacity under different settings, which enable us to develop managerial insights. © 2008 The Author(s).Item Open Access Integrated capacity and inventory management with capacity acquisition lead times(Elsevier, 2009-08-01) Mincsovicz, G.; Tan, T.; Alp, O.We model a make-to-stock production system that utilizes permanent and contingent capacity to meet non-stationary stochastic demand, where a constant lead time is associated with the acquisition of contingent capacity. We determine the structure of the optimal solution concerning both the operational decisions of integrated inventory and flexible capacity management, and the tactical decision of determining the optimal permanent capacity level. Furthermore, we show that the inventory (either before or after production), the pipeline contingent capacity, the contingent capacity to be ordered, and the permanent capacity are economic substitutes. We also show that the stochastic demand variable and the optimal contingent capacity acquisition decisions are economic complements. Finally, we perform numerical experiments to evaluate the value of utilizing contingent capacity and to study the effects of capacity acquisition lead time, providing useful managerial insights.Item Open Access Integrated workforce capacity and inventory management under labour supply uncertainty(Taylor & Francis, 2009) Pac, M. F.; Alp, O.; Tan, T.In a manufacturing environment with volatile demand, inventory management can be coupled with dynamic capacity adjustments for handling the fluctuations more effectively. In this study, we consider the problem of integrated capacity and inventory management under non-stationary stochastic demand and capacity uncertainty. The capacity planning problem is investigated from the workforce planning perspective where the capacity can be temporarily increased by utilising contingent workers from an external labour supply agency. The contingent capacity received from the agency is subject to an uncertainty, but the supply of a certain number of workers can be guaranteed through contracts. There may also be uncertainty in the availability of the permanent and contracted workers due to factors such as absenteeism and fatigue. We formulate a dynamic programming model to make the optimal capacity decisions at a tactical level (permanent workforce size and contracted number of workers) as well as the operational level (number of workers to be requested from the external labour supply agency in each period), integrated with the optimal operational decision of how much to produce in each period. We analyse the characteristics of the optimal policies and we conduct an extensive numerical analysis that helps us provide several managerial insights.Item Open Access Modelling imperfect advance demand information and analysis of optimal inventory policies(Elsevier, 2006) Tan, T.; Güllü, R.; Erkip, N.We consider an inventory control problem where it is possible to collect some imperfect information on future demand. We refer to such information as imperfect Advance Demand Information (ADI), which may occur in different forms of applications. A simple example is a company that uses sales representatives to market its products, in which case the collection of sales representatives' information as to the number of customers interested in a product can generate an indication about the future sales of that product, hence it constitutes imperfect ADI. Other applications include internet retailing, Vendor Managed Inventory (VMI) applications and Collaborative Planning, Forecasting, and Replenishment (CPFR) environments. We develop a model that incorporates imperfect ADI with ordering decisions. Under our system settings, we show that the optimal policy is of order-up-to type, where the order level is a function of imperfect ADI. We also provide some characterizations of the optimal solution. We develop an expression for the expected cost benefits of imperfect ADI for the myopic problem. Our analytical and empirical findings reveal the conditions under which imperfect ADI is more valuable.Item Open Access Rekabetin korunmasında Rekabet Kurulu ile yargı organlarının rolü: işlevsel işbirliği üzerine bazı gözlemler(Galatasaray Üniversitesi, 2004) Tan, T.Item Open Access Sağlık hizmeti ihale yoluyla satın alınabilir mi?: kamu hizmetinin özelleştirilmesi konusunda bir örnek olay(İstanbul Üniversitesi, 2011) Tan, T.Item Open Access Tactical capacity management under capacity flexibility(Institute of Industrial Engineers, 2008) Alp, Osman; Tan, T.In many production systems a certain level of flexibility in the production capacity is either inherent or can be acquired. In that case, system costs may be decreased by managing the capacity and inventory in a joint fashion. In this paper we consider such a make-to-stock production environment with flexible capacity subject to periodic review under non-stationary stochastic demand, where we allow for positive fixed costs both for initiating production and for acquiring external capacity. Our focus is on tactical-level capacity management which refers to the determination of in-house production capacity while the operational-level integrated capacity and inventory management is executed in an optimal manner. We first develop a simple model to represent this relatively complicated problem. Then we elaborate on the characteristics of the general problem and provide the solution to some special cases. Finally, we develop several useful managerial insights as to the optimal capacity level, the effect of operating at a suboptimal capacity level and the value of utilizing flexible capacity.Item Open Access Using imperfect advance demand information in ordering and rationing decisions(Elsevier, 2009) Tan, T.; Güllü, R.; Erkip, N.In this paper, we consider an inventory problem with two demand classes having different priorities. The appropriate policy of rationing the available stock, i.e. reserving some stock for meeting prospective future demand of preferred customers at the expense of deliberately losing some of the currently materialized demand of lower demand class(es), relies on the estimation of the future demand. Utilizing current signals on future demand, which we refer to as imperfect advance demand information (ADI), decreases uncertainty on future demand and may help to make better decisions on when to start rejecting lower class demand. We develop a model that incorporates imperfect ADI with inventory ordering (replenishment) decision and rationing available stock. In a two-period setting, we show some structural properties, solve the rationing problem, and propose solution methods based on Monte Carlo simulation for the ordering problem. We conduct numerical tests to measure the impact of system parameters on the expected value of imperfect ADI, and provide useful managerial insights.Item Open Access Yasama faaliyetinden devletin sorumluluğu: (Danıştay Dava Daireleri Kurulu’nun bir kararı üzerine)(Ankara Üniversitesi, 2015) Tan, T.