Le contentieux gréco-turc en mer Egée

A l'origine du contentieux gréco-turc en mer Égée se trouve la condition politico-géographique des îles égéennes. Ces conflits ouverts ou latents, comprennent à l'époque où l'article a été rédigé l'espace marin, l'espace aérien ainsi que la question de la démilitarisation des îles égéennes orientales. Les conflits relatifs à l'espace marin portent essentiellement sur le plateau continental et sur la divergence de vue sur l'étendue de la mer territoriale. Les conflits relatifs à l'espace aérien portent essentiellement sur l'étendue de l'espace aérien, sur l'aire du contrôle de sécurité de l'aviation civile et sur les zones de commandement dans le cadre de l'OTAN. Quant à la question de la démilitarisation des îles égéennes orientales l'article fournit les données de la question et les thèses respectives des deux parties la concernant. La conclusion de l'article est que la seule solution réellement possible serait un “ package deal ” sur l'ensemble des problèmes

Picture scrambler for digital video

Bu çalışmada, sayısal şifreli yayıncılık ortamında kullanılan “bit dizilerinin şifrelenmesi” yöntemine alternatif olarak resimde görsel bozukluk oluşturan bir yöntem önerilmektedir. Böylece izleyicinin içeriğe kısıtlı erişimi ve mevcut sistemlerde ek güvenlik sağlanmış olmaktadır. Algoritma resim içeriğini altbloklara bölerek, beneklerin RGB bileşenlerini  değiştirmekte ve şifrenin çözümü için gerekli tüm veriyi resim içinde saklamaktadır. Böylece yöntem var olan tüm sistemlerle kullanılabilir, tüm standartlarla uyumludur. Bunun tek önkoşulu MPEG ile uyumluluktur. Görsel bozulmaya dayalı klasik şifreli yayın yöntemleri MPEG ile verimli kodlanamaz.Bu çalışmada önerilen yöntem, bu probleme özgün bir çözüm içermektedir. Resim içinde veri taşınması önemli bir güvenlik avantajı sunar.Anahtar Kelimeler: MPEG, sayısal televizyon, şifreli yayıncılık, telif hakları.The current conditional access  techniques for digital TV systems depend on encrypting MPEG-2 data packets at the bitstream level. Known methods, using visual distortion, can not be used in digital systems because they produce video sequences which can not be encoded with MPEG-2 efficiently. This paper examines the conditions of scrambling systems using visual distortion for MPEG-2 compliance and then proposes a solution which fulfills them. In order to obtain usability with existing systems, the proposed method must be independent of all the parameters in digital broadcasting systems such as channel, bit-rate, modulation etc. This is possible if the method is MPEG-2 transparent. The algoritm works in any case where an MPEG-2 video can be transmitted and displayed.The main condition of this is to carry the related information within the video sequence. This is realised by using the subblock boundaries which are created by the scrambling and the TV logo which exists in all broadcasts. Transmission of scrambling parameters in images enables a high degree of security and flexibility.The main concept to modify the pixel values of the original content enables also various applications for copyright protection in other digital distribution channels like VoD, DVD, PVR etc.Keywords: MPEG-2, digital TV, scrambled broadcast, copyright protection

Hamiltonian formalism for nonlinear Schr\"{o}dinger equations

We study the Hamiltonian formalism for second order and fourth order nonlinear Schr\"{o}dinger equations. In the case of second order equation, we consider cubic and logarithmic nonlinearities. Since the Lagrangians generating these nonlinear equations are degenerate, we follow the Dirac-Bergmann formalism to construct their corresponding Hamiltonians. In order to obtain consistent equations of motion, the Dirac-Bergmann formalism imposes some set of constraints which contribute to the total Hamiltonian along with their Lagrange multipliers. The order of the Lagrangian degeneracy determines the number of the primary constraints. Multipliers are determined by the time consistency of constraints. If a constraint is not a constant of motion, a secondary constraint is introduced to force the consistency. We show that for both second order nonlinear Schr\"{o}dinger equations we only have primary constraints, and the form of nonlinearity does not change the constraint dynamics of the system. However, introducing a higher order dispersion changes the constraint dynamics and secondary constraints are needed to construct a consistent Hamilton equations of motion.Comment: 8 page

Hamiltonian formalism for nonlinear Schrödinger equations

We study the Hamiltonian formalism for second and fourth order nonlinear Schrödinger equations. In the case of the second order equation, we consider cubic and logarithmic nonlinearities. Since the Lagrangians generating these nonlinear equations are degenerate, we follow the Dirac–Bergmann formalism to construct their corresponding Hamiltonians. In order to obtain consistent equations of motion, the Dirac–Bergmann formalism imposes some set of constraints that contribute to the total Hamiltonian along with their Lagrange multipliers. The order of the Lagrangian degeneracy determines the number of primary constraints. If a constraint is not a constant of motion, a secondary constraint is introduced to force the consistency condition. We show that for second order and fourth order nonlinear Schrödinger equations we only have primary constraints, and the form of nonlinearity or the order of derivatives does not change the constraint dynamics of the system. However, we observe that introducing new fields to treat higher derivatives in the Lagrangians of these equations changes the constraint dynamics, and secondary constraints are needed to construct a consistent set of Hamilton equations

The effects of daylight exposure on melatonin levels, Kiss1 expression, and melanoma formation in mice

Aim To determine how daylight exposure in mice affects melatonin protein expression in blood and Kiss1 gene expression in the hypothalamus. The second aim was to assess the relationship between skin cancer formation, daylight exposure, melatonin blood level, and kisspeptin gene expression level. Methods New-born mice (n = 96) were assigned into the blind group or daylight group. The blind group was raised in the dark and the daylight group was raised under 12 hours light/12 hours dark cycle for 17 weeks. At the end of the 11th week, melanoma cell line was inoculated to mice, and tumor growth was observed for 6 weeks. At the end of the experiment, melatonin level was measured from blood serum and Kiss1 expression from the hypothalamus. Results The blind group had significantly higher melatonin and lower Kiss1 expression levels than the daylight group. Tumor volume was inversely proportional to melatonin levels and directly proportional to Kiss1 expression levels. Tumor growth speed was lower in the blind than in the daylight group. Conclusion Melatonin and Kiss1 were shown to be nvolved in tumor suppression. They were affected by daylight and were mutually affected by each other

Le contentieux gréco-turc en Mer Egée

Pazarci Hüseyin. Le contentieux gréco-turc en Mer Egée. In: CEMOTI, n°2-3, 1986. Le différend gréco-turc. pp. 67-85