Practical Integrated Design Strategies for Opaque and All-Optical DWDM Networks: Optimization Models and Solution Procedures

Dense wavelength division multiplexing (DWDM) opaque networks use expensive optical/electrical/optical (O/E/O) conversion at each end of a fiber link. Several technological advances have been used in an attempt to reduce the O/E/O conversion cost component: improved optical amplifiers using distributed Raman amplification allow signals to traverse longer distances without amplification and/or regeneration; optical switches allow the signal to remain in the optical domain most of the time. Networks that use this equipment to eliminate some of the O/E/O conversions are called transparent or all-optical networks and benefit from reduced capital costs at the expense of operational costs and complexity in order to handle potential adjustments in traffic demand. In this investigation, we develop optimization-based algorithms for DWDM network design and traffic routing for both opaque and all-optical networks. This study compares the performance of AMPL/CPLEX implementations of both algorithms on realistically sized networks with up to 36 nodes and 67 links. In all test cases considered the all-optical network design is substantially less expensive than the traditional opaque network design with cost reductions in the range of 12% to 26%.     

The development, validity and reliability of TPACK-deep: A technological pedagogical content knowledge scale

The purpose of this study is to develop a TPACK (technological pedagogical content knowledge) scale based on the centered component of TPACK framework in order to measure preservice teachers’ TPACK. A systematic and step-by-step approach was followed for the development of the scale. The validity and reliability studies of the scale were carried out with 995 Turkish preservice teachers. The sample was split into two subsamples on random basis (n1 = 498, n2 = 497). The first sample was used for Exploratory Factor Analysis (EFA) and the second sample for Confirmatory Factor Analysis (CFA). After the EFA, the TPACK-deep scale included 33 items and had four factors. These factors were design, exertion, ethics and proficiency. The Cronbach’s alpha coefficient for the whole scale was found to be .95, whereas the values of Cronbach’s alpha coefficient for individual factors of the scale ranged between .85 and .92. The CFA was conducted within the scope of the validity study of the scale. In this way, this structure of the 4-factor scale was confirmed. In addition, the test-retest reliability coefficient of the scale was calculated as .80. The findings revealed that the TPACK-deep scale was a valid and reliable instrument for measuring TPACK. Consequently, various suggestions were put forward regarding the use the TPACK-deep scale for applied research and for future studies.     

Measuring cognitive load in test items: static graphics versus animated graphics

The majority of multimedia learning studies focus on the use of graphics in learning process but very few of them examine the role of graphics in testing students' knowledge. This study investigates the use of static graphics versus animated graphics in a computer‐based English achievement test from a cognitive load theory perspective. Three hundred and three 7th‐grade students were randomly split into two groups and given the test questions either with static graphics or with animated graphics accompanied with text. Students' response time, response accuracy, self‐reported ratings on cognitive load and secondary task approach were used to measure their cognitive load. Findings revealed that animating graphics increased the response time and secondary task scores of the students but did not have any significant effect on their test success. Furthermore, no difference was observed in self‐reported cognitive loads. The relationship between the four different cognitive load measures was also examined in the study. No direct relation was found between self‐reported ratings and secondary task scores. On the other hand, self‐ratings and response accuracy were found to be more sensitive to intrinsic cognitive load, whereas response time and secondary task measures were found to be more sensitive to extraneous cognitive load in our testing environment.     

Selection of computer-integrated manufacturing technologies using a combined analytic hierarchy process and goal programming model

Investment in computer-integrated manufacturing (CIM) is a multi-attribute problem, which includes both qualitative and quantitative factors. In order to select the best set of CIM alternatives among the competing ones it is necessary to make a trade off between the quantative and qualitative factors some of which may conflict. Selection of appropriate CIM alternatives is vital in manufacturing companies’ long-term competitiveness, and it requires development of selection models. The selection model must consider various quantative and qualitative objectives and constraints simultaneously. For example, companies have generally limited funds to invest in new advanced technology. The size of the allocated fund limits the types and number of CIM alternatives a company can select in a given time period. In this article, a combined model of the analytical hierarchy process and goal programming is proposed to consider multiple objectives and constraints simultaneously. A real-world example is provided to illustrate the application of the combined approach.     

The alteration degree of the metacrystalline rocks based on UAI,Bolu (Turkey)

The geomechanical properties of the metacrystalline rock masses vary due to alteration. The Devonian aged Yedigoller formation crops out in the Asarsuyu valley (Bolu, Turkey). The aim of this study is to investigate the alteration degree of the amphibolite and metagranodiorites based on their geomechanical and petrographical properties. The P-wave velocity is 1,613–5,588 m/s and the unconfined compressive strength varies between 12.75 and 99.86 MPa. Several weathering products occurred due to carbonisation, oxidation and sericitation. These rocks, subjected to hydrothermal effects, are classified as “fresh” to “completely altered” according to the unified alteration index (UAI). In addition, the values of the loss on ignition, modified weathering potential index and chemical index of alteration were taken into account for supporting the alteration process. Since the main process is hydrothermal alteration, the rocks which were exposed to alteration are weathered on the slopes after excavation. Weathering classification and the chemical indices indicate this process. Thus, UAI is concluded to be more suitable and credible in order to evaluate the hydrothermal alteration process of such crystalline rocks numerically.     

Epididymo-orchitis as a complication of brucellosis

A study of 84 patients who were diagnosed with epididymo-orchitis between July 1987 and September 1993 is presented. Brucellosis was a complication in 14 cases (17%). All 14 cases had elevated agglutination titers. Brucella blood culture was found to be positive in 4 of 14 cases (28.5%). Standard therapy regime (streptomycin plus tetracycline) was effective in 13 of 14 (93%) cases.     

Inhalation of foreign bodies in children. Report of 500 cases

Inhalation of foreign bodies is a major cause of accidental death during childhood. Aspiration of foreign bodies is common in children aged 1 to 3 years, especially in boys. A past history of foreign body aspiration is itself an indication for bronchoscopic examination of the airways, because some children with aspirated foreign bodies are without symptoms and chest x-ray films may not show abnormalities. Bronchoscopic removal of the foreign bodies requires close communication between the anesthesiologist and the endoscopist. Forgotten foreign bodies in the airways cause chronic pulmonary infections, allergic asthma, bronchiectatic changes, and lung abscess. Foreign bodies that cannot be grasped by bronchoscopic forceps should be removed by thoracotomy and bronchotomy. This report describes our experience in 500 children with suspected foreign body inhalation. We routinely use prednisolone, 1 to 2 mg. per kilogram, and nebulization just after bronchoscopic examination of the airways. This medication greatly diminishes the rate of postbronchoscopic complications such as laryngeal edema, which require tracheostomy. In our series of 500 case, the incidence of postbronchoscopic tracheostomy is 1.4 per cent and the total mortality rate is 1.8 per cent.     

Manifold learning for face recognition under changing illumination

Appearance-based methods have been proven to be useful for face recognition tasks. The main problem with appearance-based methods originates from the multimodality of face images. It is known that images of different people in the original data space are more closely located to each other than those of the same person under different imaging conditions. In this paper, we propose a novel approach based on the nonlinear manifold embedding to define a linear subspace for illumination variations. This embedding based framework utilizes an optimization scheme to calculate the bases of the subspace. Since the optimization problem does not rely on the physical properties of the factor, the framework can also be used for other types of factors such as pose and expression. We obtained some promising recognition results under changing illumination conditions. Our error rates are comparable with state of art methods.