Fabrication of Planar Waveguide Chip for Splitting or Combining an Infrared Light Beam

Nguyen Thanh Binh,Nguyen Tat Thanh,Duong Thanh Trung,Nguyen Thanh Huong,Le Quoc Minh 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

Based on hybrid materials of polymethamethyl acrylat, silica and zirconia (ASZ)/Titania (AST), some planar structures of optical power splitter/combiner type 1×N channels were designed and simulated for making masks by using computer software. Splitter chips were then fabricated by using the thin-film sol-gel technique and their structure was formed by using a direct photo-patterning method with UV light and a mask. A conformation of the waveguide was tested with an Alpha-Step IQ system. The waveguide properties of the splitter were measured with a 1550 nm laser source. The experimental results show that the light was transmitted through the chip with a total output efficiency of around 6% and was separated uniformly at the output channels. Based on hybrid materials of polymethamethyl acrylat, silica and zirconia (ASZ)/Titania (AST), some planar structures of optical power splitter/combiner type 1×N channels were designed and simulated for making masks by using computer software. Splitter chips were then fabricated by using the thin-film sol-gel technique and their structure was formed by using a direct photo-patterning method with UV light and a mask. A conformation of the waveguide was tested with an Alpha-Step IQ system. The waveguide properties of the splitter were measured with a 1550 nm laser source. The experimental results show that the light was transmitted through the chip with a total output efficiency of around 6% and was separated uniformly at the output channels.

Intelligent vision system for multi-rotor UAVs in SAR operations

Trung-Thanh Ngo,Jae-Min Lee,Dong-Seong Kim 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.1

Development of 3D CAM system for End mills manufacturing

Trung-Thanh Pham,Sung-Lim Ko,Yong-Hyun Kim 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월

The development of 3D CAM system for the manufacturing of end mills becomes a key approach to save the time and reduce cost for end mills manufacturing. This paper presents the calculation and simulation of end mill tools CNC machining bases on 5-axes CNC grinding machine tool. In this study describes the process of generation and simulation of grinding point data between the tool and the grinding wheels through the machined time. Depend on input data of end mill geometry, wheels geometry, wheel setting, machine setting the end mill configuration and NC code for machining will be generated and visualized in 3 dimension before machining. The 3D visualizations of end mill manufacturing was generated by using OpenGL in C++. The development software was designed by using Microsoft Visual C++, which has many advantages for users, saving time and reducing manufacturing cost.

Design and implementation of an automated, long-range selfie camera system using LORA

Trung-Thanh Ngo,Dong-Seong Kim 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

This paper proposes an automated, long-range selfie camera system using LORA (LORA-SELFIE). LORASELFIE addresses the FOV problem of smart phone cameras by enabling users to take selfies and landscape photos automatically from a distance. On LORA-SELFIE, a wireless sensor network is used to track users presence at designated shooting spots. If a user is not found at the designated spot, LORA-SELFIE goes to sleep mode to save energy. Moreover, the operating range of LORA-SELFIE can be extended easily by adding more relay nodes to the network. Experimental results show that LORA-SELFIE solves the FOV problem and is even better than an existing commercial system in terms of energy-consumption, and processing time.

Impact of Psychological Capital on Job Performance and Job Satisfaction: A Case Study in Vietnam

Trung Thanh NGO 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.5

Business leaders have made great efforts to increase their organizations’ competitive capability, and raising employees’ job performance is considered as one of the essential solutions. Thus, it is vital to properly identify factors that affect the job performance since this will be the basis for managers to propose recommendations to increase employees’ job performance. The study seeks to investigate the relationships between psychological capital, job satisfaction, and job performance of employees in Vietnam, a developing country in South-East Asia. In this study, psychological capital is considered as a high-order construct. The mixed research method is used in this study. Qualitative research method is used to form the official survey questionnaire. Quantitative research method is used for investigating the relationships between concepts. Research data are collected from 848 interviewees via both face-to-face and email surveys. The findings show that psychological capital has positive relationships with job satisfaction and job performance. Job satisfaction also has a positive impact on job performance. In particular, job satisfaction shows the mediating role in the impact of employees’ psychological capital on their job performance. Based on the results, the study also provides recommendations related to psychological capital and job satisfaction assisting managers to increase employees’ job performance.

A Phosphate Starvation-Inducible Ribonuclease of Bacillus licheniformis

( Thanh Trung Nguyen ),( Minh Hung Nguyen ),( Huy Thuan Nguyen ),( Hoang Anh Nguyen ),( Thi Hoi Le ),( Thomas Schweder ),( Britta Jurgen ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.8

The BLi03719 protein of Bacillus licheniformis DSM13 belongs to the most abundant extracellular proteins under phosphate starvation conditions. In this study, the function of this phosphate starvation inducible protein was determined. An amino-acid sequence analysis of the BLi03719-encoding gene showed a high similarity with genes encoding the barnase of Bacillus amyloliquefaciens FZB42 and binase-like RNase of Bacillus pumilus SARF-032. The comparison of the control strain and a BLi03719-deficient strain revealed a strongly reduced extracellular ribonuclease activity of the mutant. Furthermore, this knockout mutant exhibited delayed growth with yeast RNA as an alternative phosphate and carbon source. These results suggest that BLi03719 is an extracellular ribonuclease expressed in B. licheniformis under phosphate starvation conditions. Finally, a BLi03719 mutant showed an advantageous effect on the overexpression of the heterologous amyE gene under phosphate-limited growth conditions.

Compliance of education journals in Vietnam with the minimum criteria to be indexed in the ASEAN Citation Index and Scopus

Trung Tran,Loc Thi My Nguyen,Thanh Thi Nghiem,Hien Thi Thu Le,Cuong Huu Nguyen,Thuy Phuong La,Trung Tien Nguyen,Hang Thi-Thu Nguyen 한국과학학술지편집인협의회 2019 Science Editing Vol.6 No.2

This study aimed at elucidating the present situation of scholarly journals published in Vietnam according to the minimum criteria to be indexed in the ASEAN Citation Index (ACI) and Scopus, with the goal of suggesting development strategies for scholarly journals in Vietnam. From the 387 journals accredited by the Vietnamese State Council for Professorship, 13 education journals were arbitrarily selected, and their compliance with the five minimum criteria for the ACI (peer review, timeliness, abstracts in English, references in Roman script, and a website in English) and the six minimum criteria for Scopus (peer review, timeline, abstracts in English, references in Roman characters, Electronic International Standard Serial Number [ISSN], and publication ethics) were assessed. Two of the 13 journals were eligible to be indexed in the ACI, while none fulfilled the minimum criteria to be indexed in Scopus. An urgent task for the editors of those journals is to establish an informative journal homepage in English that provides basic information on the journal. Then, an Electronic ISSN can be obtained from the ISSN International Center. Furthermore, the following steps are suggested for journal promotion: establishment of appropriate editorial policies and publication ethics procedures, improvement of research integrity, enhancement of the journals’ reputation in the international scientific community, and improvement of the online publishing system by adopting a journal manuscript management system. To achieve those goals, financial support from the Vietnamese government will be invaluable.

Illumination-Robust Lip Detection for Smartphone Applications

Thanh Trung Pham,Min Gyu Song,Jin Young Kim,Seung You Na 한국정보기술학회 2011 한국정보기술학회논문지 Vol.9 No.2

Natural lighting condition has been the limitation of automatic lip detection in the lip reading. To cope with the problem, we present a robust lip detection algorithm applicable to lip reading in the smartphone environments. Our proposed lip detection approach utilizes the partial color based clustering, clustering with geometric feature and fuzzy confidence based verification. The partial clustering into multiple clusters based on color information can model the skin, lips and other regions sufficiently and enables to avoid the effect of illumination on the lip images. The geometry based clustering is used to efficiently separate lips from other regions and combine the discrete components of one facial feature. The lip confidence using fuzzy rules is introduced to select the best segmented lip candidate. To validate the proposed algorithm, we constructed database in standard, indoor, outdoor environment. The experimental results show that in each environment the lip detection performance of our proposed method enhanced at abut 7%, 13%, 26% than conventional approaches. Through the experiments, we have shown the robustness against illumination and lightweight performance of our proposed algorithm compared to the conventional approaches.

Analysis of tensile properties for composites with wrinkled fabric

Thanh Trung Do,이동주 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.2

During the fiber preform loading process of resin transfer moldings (RTMs), fabric layers can be wrinkled in the preform, which affects the quality of the composite. This study considers several wrinkled models with different wrinkled lengths (LW) and different numbers of wrinkled layers in the preform. To study the effects of wrinkling on tensile properties, two matrix materials with different moduli are used to enhance understanding. It is found that the tensile moduli of wrinkled models are lower than those of the normal model, for the same fiber volume fraction (Vf). The effects of wrinkling on the tensile modulus increase with the number of layers as well as Vf. In addition, the effect of wrinkling with a low-modulus matrix on the tensile modulus is larger than that with a high-modulus matrix in the composite. Based on the failure modes and the stiffness of materials, the failure mechanisms of wrinkled models can be separated into two regimes as a function of wrinkled length, LW, depending on the critical wrinkled length (LWC).

Micropropagation from root segments to improve seedling quality in Chinese foxglove crops

Thanh Loan Pham,Van Huy Nguyen,Thi Le Thu Hoang,Thi Tam Tien Ha,Trung Kien Tran,Xuan Duong Vu,Phi Bang Cao,Quang Trung Nguyen 한국식물생명공학회 2020 JOURNAL OF PLANT BIOTECHNOLOGY Vol.47 No.3

This is the first study to establish a complete protocol for micropropagation of Rehmannia glutinosa from root segments. The study involved investigating the effect of plant growth regulators on in vitro shoot regeneration and rooting and identifying substrates supporting survival and growth performance of ex vitro seedlings. A Murashige and Skoog (MS) medium containing 30 g/L sucrose for shoot induction and 0.2 mg/L indole-3-acetic acid (IAA), 1 mg/L 6-benzylaminopurine (BAP), and 1 g/L polyvinylpyrrolidone (PVP) for shoot multiplication resulted in the highest number of shoots per explant and shoot height. Applying a medium containing 0.5 mg/L IAA and 1 g/L PVP yielded optimal rooting of the shoots grown in vitro. Compost enriched with microbial inoculants and perlite enhanced seedling growth better than that with organic biofertilizer-free substrates (soil and sand). We recommend the continuous production of micropropagated R. glutinosa seedlings from root segments under the aforementioned conditions as a possible propagation technique for crops of this species.