Trapping Center Parameters and Optical Absorption in Quaternary Tl4In3GaS8, Tl4InGa3Se8, and Tl2InGaS4 Semiconductors

Nizami Gasanly 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.4

We have carried out thermally stimulated current measurements on as-grown Tl4In3GaS8, Tl4InGa3Se8, and Tl2InGaS4 crystals in the low-temperature ranges of 10 . 90, 10 . 160, and 10 . 60 K, respectively. Using the different heating rates method, we revealed experimental evidence for trapping centers with activation energies of 12 meV (Tl4In3GaS8), 17 meV (Tl4InGa3Se8), and 10 meV (Tl2InGaS4). The capture cross sections of the traps were found to be 3.0 × 10.25, 2.0 × 10.26, and 1.3 × 10.24 cm2, respectively. The values of the activation energies were compared with those obtained in photoluminescence experiments. From an optical absorption study, the energies of the indirect band gaps were determined for the crystals studied.

Temperature Dependence of Raman-active Modes of TlGaS2 Layered Crystals: an Anharmonicity Study

Nizami Gasanly,A. Aydinli,H. Ozkan,N. S. Yuksek 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.2

The temperature dependence (16 - 300 K) of unpolarized Raman spectra from TlGaS2 layered crystals was measured in the frequency range of 10 - 400 cmThe analysis of the experimental data showed that the temperature dependencies of the phonon frequencies and linewidths were well described by considering the contributions from thermal expansion and lattice anharmonicity. The anharmonic contribution (phonon-phonon coupling) was found to be due to three-phonon processes. The present work demonstrates that the interlayer Raman mode at 42.6 cmshifts toward high frequency as the temperature is raised from 16 to 300 K.

UPPER BOUND OF SECOND HANKEL DETERMINANT FOR A SUBCLASS OF BI-UNIVALENT FUNCTIONS OF COMPLEX ORDER

Mustafa, Nizami Korean Mathematical Society 2019 대한수학회논문집 Vol.34 No.3

In this paper, we introduce and investigate a subclass ${\Im}_{\Sigma}({\alpha},{\beta},{\gamma})$ of analytic and bi-univalent functions of complex order in the open unit disk U in complex plane. Here, we obtain an upper bound for the second Hankel determinant of the functions belonging to this class. Moreover, several interesting conclusions of the results obtained here are also discussed.

얼굴과 발걸음을 결합한 인식

Imran Fareed Nizami,안성제(Sungje An),홍성준(Sungjun Hong),이희성(Heesung Lee),김은태(Euntai Kim),박민용(Minnon Park) 한국지능시스템학회 2008 한국지능시스템학회논문지 Vol.18 No.1

개인 식별 연구는 보안, 감시 시스템에서 중요한 부분이다. 최선의 성능을 가진 시스템을 설계하기 위하여 감지기들로부터 최대 정보를 이용할 수 있도록 설계한다. 다양한 생체 인식 시스템은 등록, 확인, 또는 개인 식별을 위하여 생리 특성이나 행동 특성을 하나이상 활용한다. 발걸음 인식만을 가지고는 아직 개인별 변별적 특징을 안정적으로 나타내지 못하므로, 본 논문에서는 얼굴과 발걸음을 결합한 개인 식별 시스템을 제안한다. 본 논문에서 우리는 한 개의 카메라를 이용한다. 즉, 얼굴과 발걸음 인식 모두 하나의 카메라를 이용하여 획득된 같은 이미지 셋을 사용한다. 본 논문의 중점은 이미지들에서 이용할 수 있는 최대 정보량을 활용하는 것으로 시스템의 성능을 향상시키는 것이다. 결합은 결정 단계에서 고려된다. 제안된 알고리듬은 NLPR 데이터베이스를 사용한다. Identification of humans from multiple view points is an important task for surveillance and security purposes. For optimal performance the system should use the maximum information available from sensors. Multimodal biometric systems are capable of utilizing more than one physiological or behavioral characteristic for enrollment, verification, or identification. Since gait alone is not yet established as a very distinctive feature, this paper presents an approach to fuse face and gait for identification. In this paper we will use the single camera case i.e. both the face and gait recognition is done using the same set of images captured by a single camera. The aim of this paper is to improve the performance of the system by utilizing the maximum amount of information available in the images. Fusion in considered at decision level. The proposed algorithm is tested on the NLPR database.

Fusion algorithm for Integrated Face and Gait Identification

Imran Fareed Nizami,Sugjun Hong,Heesung Lee,Toh kar Ann,Euntai Kim,Mignon Park 한국지능시스템학회 2007 한국지능시스템학회 학술발표 논문집 Vol.17 No.2

Identification of humans from multiple view points is an important task for surveillance and security purposes. For optimal performance the system should use the maximum information available from sensors. Multimodal biometric systems are capable of utilizing more than one physiological or behavioral characteristic for enrollment, verification, or identification. Since gait alone is not yet established as a very distinctive feature, this paper presents an approach to fuse face and gait for identification. In this paper we will use the single camera case i.e. both the face and gait recognition is done using the same set of images captured by a single camera. The aim of this paper is to improve the performance of the system by utilizing the maximum amount of information available in the images. Fusion is considered at decision level. The proposed algorithm is tested on the NLPR database.

A RECURRENCE RELATION FOR THE JONES POLYNOMIAL

Berceanu, Barbu,Nizami, Abdul Rauf Korean Mathematical Society 2014 대한수학회지 Vol.51 No.3

Using a simple recurrence relation, we give a new method to compute the Jones polynomials of closed braids: we find a general expansion formula and a rational generating function for the Jones polynomials. The method is used to estimate the degree of the Jones polynomials for some families of braids and to obtain general qualitative results.

Non-Stationary Response of a Vehicle Obtained From a Series of Stationary Responses

Tuncay KARACAY,Nizami AKTURK,Mehmet EROGLU BA 대한기계학회 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.9

Ride characteristics of a vehicle moving on a rough ground with changing travel velocity are analyzed in this paper. The solution is difficult due to the non-stationary characteristics of the problem. Hence a new technique has been proposed to overcome this difficulty. This new technique is employed in the analysis of ride characteristics of a vehicle with changing velocity in the time/frequency domain. It is found that the proposed technique gives successful results in modelling non-stationary responses in terms of a series of stationary responses.

Thermally stimulated current measurements in as-grown TlGaSeS layered single crystals

Tacettin Yıldırım,Nizami M. Gasanly 한국물리학회 2009 Current Applied Physics Vol.9 No.6

Charge carrier traps in as-grown TlGaSeS layered single crystals were studied using thermally stimulated current measurements. The investigations were performed in temperatures ranging from 10 to 100 K. The experimental evidences were found for the presence of one shallow hole trapping center in TlGaSeS, located at 12 meV from the valence band. The trap parameters have been calculated using various methods of analysis, and these agree well with each other. Its capture cross-section and concentration have been found to be 8.9 × 10-26 ㎠ and 2.0 × 1014 cm-3, respectively. Analysis of the thermally stimulated current data at different light excitation temperatures leads to a value of 19 meV/decade for the shallow hole traps distribution. Charge carrier traps in as-grown TlGaSeS layered single crystals were studied using thermally stimulated current measurements. The investigations were performed in temperatures ranging from 10 to 100 K. The experimental evidences were found for the presence of one shallow hole trapping center in TlGaSeS, located at 12 meV from the valence band. The trap parameters have been calculated using various methods of analysis, and these agree well with each other. Its capture cross-section and concentration have been found to be 8.9 × 10-26 ㎠ and 2.0 × 1014 cm-3, respectively. Analysis of the thermally stimulated current data at different light excitation temperatures leads to a value of 19 meV/decade for the shallow hole traps distribution.

Characteristics of natural rubber hybrid composites based on marble sludge/carbon black and marble sludge/rice husk derived silica

Khalil Ahmed,Shaikh Sirajuddin Nizami,Nudrat Zahid Raza 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4

This paper discusses an extensive overview of characterization of marble sludge (MS) with carbon black (CB) and rice husk derived silica (RHS) in hybrid natural rubber (NR) composite. Cure characteristics,mechanical and swelling properties of MS/CB and MS/RHS hybrid NR composite were investigated. As CB and RHS content increases in weight ratio of MS/CB and MS/RHS a decrease in scorch and cure time and increase in the torque, tensile, tear, modulus, hardness, crosslink density were observed, while elongation at break and swelling coefficient decreased. The aging behavior of corresponding hybrid composite materials was also evaluated at two different temperatures.

Modern Interpretation of Giant Cell Tumor of Bone: Predominantly Osteoclastogenic Stromal Tumor

Yuhree Kim,,Saqib Nizami,Hana Goto,Francis Y. Lee 대한정형외과학회 2012 Clinics in Orthopedic Surgery Vol.4 No.2

Owing to striking features of numerous multinucleated cells and bone destruction, giant cell tumor (GCT) of bone, often calledas osteoclastoma, has drawn major attractions from orthopaedic surgeons, pathologists, and radiologists. The name GCT or osteoclastomagives a false impression of a tumor comprising of proliferating osteoclasts or osteoclast precursors. The underlyingmechanisms for excessive osteoclastogenesis are intriguing and GCT has served as an exciting disease model representing a paradigmof osteoclastogenesis for bone biologists. The modern interpretation of GCT is predominantly osteoclastogenic stromal celltumors of mesenchymal origin. A diverse array of infl ammatory cytokines and chemokines disrupts osteoblastic differentiation andpromotes the formation of excessive multi-nucleated osteoclastic cells. Pro-osteoclastogenic cytokines such as receptor activatorof nuclear factor kappa-B ligand (RANKL), interleukin (IL)-6, and tumor necrosis factor (TNF) as well as monocyte-recruiting chemokinessuch as stromal cell-derived factor-1 (SDF-1) and monocyte chemoattractant protein (MCP)-1 participate in unfavorable osteoclastogenesisand bone destruction. This model represents a self-suffi cient osteoclastogenic paracrine loop in a localized area. Consistent with this paradigm, a recombinant RANK-Fc protein and bisphosphonates are currently being tried for GCT treatment inaddition to surgical excision and conventional topical adjuvant therapies.