Discussion of “clustering on dissimilarity Representations for detecting mislabelled Seismic signals at Nevado del Ruiz Volcano” by Mauricio Orozco-Alzate, and César Germán Castellanos-Domínguez

The authors are to be congratulated for a systematic investigationof the accurate and non subjective classifying approach in seismic research. The authors have conducted several clustering algorithms to the seismic event records from Volcanological and SeismologicalObservatory at Manizales. Their objective was to improve the grouping of seismic data (i.e., volcano-tectonic earthquakes, long-period earthquakes and icequakes) digitized at 100.16 Hz sampling frequency.Their study seems adding new approach to their previous work of Langer et al. (2006) who applied different classification techniques to seismic data

A look ahead approach to secure multi-party protocols

Secure multi-party protocols have been proposed to enable non-colluding parties to cooperate without a trusted server. Even though such protocols prevent information disclosure other than the objective function, they are quite costly in computation and communication. Therefore, the high overhead makes it necessary for parties to estimate the utility that can be achieved as a result of the protocol beforehand. In this paper, we propose a look ahead approach, specifically for secure multi-party protocols to achieve distributed k-anonymity, which helps parties to decide if the utility benefit from the protocol is within an acceptable range before initiating the protocol. Look ahead operation is highly localized and its accuracy depends on the amount of information the parties are willing to share. Experimental results show the effectiveness of the proposed methods

Hydrologic homogeneous regions using monthly Streamflow in Turkey

Cluster analysis of gauged streamflow records into homogeneous and robust regions is an important tool for the characterization of hydrologic systems. In this paper we applied the hierarchical cluster analysis to the task of objectively classifying streamflow data into regions encompassing similar streamflow patterns over Turkey. The performance of three standardization techniques was also tested, and standardizing by range was found better than standardizing with zero mean and unit variance. Clustering was carried out using Ward’s minimum variance method which became prominent in managing water resources with squared Euclidean dissimilarity measures on 80 streamflow stations. The stations have natural flow regimes where no intensive river regulation had occurred. A general conclusion drawn is that the zones having similar streamflow pattern were not be overlapped well with the conventional climate zones of Turkey; however, they are coherent with the climate zones of Turkey recently redefined by the cluster analysis to total precipitation data as well as homogenous streamflow zones of Turkey determined by the rotated principal component analysis. The regional streamflow information in this study can significantly improve the accuracy of flow predictions in ungauged watersheds

Variables Affecting Student Motivation Based on Academic Publications

In this study, the variables having impact on the student motivation have been analyzed based on the articles, conference papers, master's theses and doctoral dissertations published in the years 2000-2017. A total of 165 research papers were selected for the research material and the data were collected through qualitative research techniques through document review and content analysis. According to the research results, the most important factors affecting student motivation are the fields of teacher, teachers’ classroom management skills and their teaching methods. In this research, factors having less influence on the student motivation are parental communication, student characteristics and study fields. In addition, relational search type was used more than others, mostly students were selected as the study group and most researches were conducted in USA and Turkey. Keywords: Motivation, classroom management, teaching method, publications   

Spontaneous arachnoid cyst rupture with subdural hygroma in a previously asymptomatic man: Case report

Aim: Spontaneous rupture of an arachnoid cyst resulting in a subdural hygroma is an infrequent event. We report an adult patient who had no previous neuroimaging and had acute onset headache, dizziness, and nausea unrelated to trauma. Case: A 67-year-old male patient was brought to the emergency service complaints of sudden onset of dizziness, headache, and vomiting while working in the garden. He described ongoing nausea and headache localized to the frontal region. Brain CT imaging was planned for the patient whose nausea and dizziness worsened while his symptomatic treatment continued. In the brain CT, a large hypodense extracerebral collection was detected in the area starting from the middle fossa in the right cerebral hemisphere and extending to the convexity level in the frontoparietal region. The patient was consulted in the neurosurgery unit. Surgical intervention was not considered, and the patient was admitted to the neurosurgery service for treatment. Due to the asymptomatic course in the service follow-ups, he was discharged with outpatient clinic control recommendations. Conclusion: This case illustrates the importance of recognizing the possibility of spontaneous rupture of an arachnoid cyst. This phenomenon should be considered as a differential diagnosis in patients without head trauma. Although it is rare, being aware of such a case is helpful in preventing possible bad outcomes.Amaç: Araknoid kistin subdural higroma ile sonuçlanan spontan rüptürü nadir görülen bir olaydır. Daha önce nörogörüntüleme yapılmamış ve travmaya bağlı olmayan akut başlangıçlı baş ağrısı, baş dönmesi ve mide bulantısı olan yetişkin bir hastayı sunuyoruz. Olgu: 67 yaşında erkek hasta bahçede çalışırken aniden başlayan baş dönmesi, baş ağrısı ve kusma şikayetleriyle acil servise getirildi. Frontal bölgeye lokalize devam eden bulantı ve baş ağrısı tarif etti. Semptomatik tedavisi devam ederken bulantı ve baş dönmesi artan hastaya beyin BT görüntüleme planlandı. Beyin BT'sinde sağ serebral hemisferde orta fossadan başlayıp frontoparietal bölgede konveksite seviyesine kadar uzanan alanda geniş hipodens ekstraserebral koleksiyon saptandı. Hasta beyin cerrahisi ünitesinde konsülte edildi. Cerrahi müdahale düşünülmedi ve hasta tedavi için beyin cerrahisi servisine yatırıldı. Servis takiplerindeki asemptomatik seyir nedeniyle poliklinik kontrol önerileri ile taburcu edildi. Sonuç: Bu vaka, araknoid kistin spontan rüptürü olasılığını bilmenin önemini göstermektedir. Bu fenomen kafa travması olmayan hastalarda ayırıcı tanı olarak düşünülmelidir. Nadir de olsa böyle bir durumun farkında olmak olası kötü sonuçların önlenmesinde yardımcı olur

The Marchenko method to solve the general system of derivative nonlinear Schr\"odinger equations

A system of linear integral equations is presented, which is the analog of the system of Marchenko integral equations, to solve the inverse scattering problem for the linear system associated with the derivative NLS equations. The corresponding direct and inverse scattering problems are analyzed, and the recovery of the potentials and the Jost solutions from the solution to the Marchenko system is described. When the reflection coefficients are zero, some explicit solution formulas are provided for the potentials and the Jost solutions in terms of a pair of constant matrix triplets representing the bound-state information for any number of bound states and any multiplicities. In the reduced case, when the two potentials in the linear system are related to each other through complex conjugation, the corresponding reduced Marchenko integral equation is obtained. The solution to the derivative NLS equation is obtained from the solution to the reduced Marchenko integral equation. The theory presented is illustrated with some explicit examples.Comment: 50 pages, 6 figure