Camellia tuyenquangensis (Theaceae), a new species from Vietnam

Ninh Nguyet Hai Le,Chiyomi Uematsu,Hironori Katayama,Lieu Thi Nguyen,Ninh Tran,Dung Van Luong,Son Thanh Hoang 한국식물분류학회 2017 식물 분류학회지 Vol.47 No.2

Camellia tuyenquangensis (Theaceae), a new yellow species of camellia from the Chiem Hoa district of the Tuyen Quang province in Vietnam, is described and illustrated. Camellia tuyenquangensis is similar to Camellia luongii but different from the latter species in several morphological features: leaves oblong-ovate to narrow elliptic; flowers 1–2; bracteoles glabrous on both sides; sepal margins ciliate; style cleft one half of the length. The morphological data provisionally support its placement in Camellia sect. Chrysantha Chang.

The Acetylcholinesterase Inhibitory Activity of Alkaloids and Iridoids from Rauvolfia cambodiana Pierre ex Pit

Ninh Khac Thanh Tung,Nguen Chi Mai,Ninh Khac Ban,Duong Thi Hai Yen,Bui Huu Tai,Phan Van Kiem,Jong Seong Kang 한국분석과학회 2023 학술대회논문집 Vol.2023 No.5

A Highly Efficient Broadband Class-E Power Amplifier with Nonlinear Shunt Capacitance

Ninh Dang-Duy,Nam Ha-Van,Daesik Jeong,Dong Hwan Kim,Chulhun Seo 한국전자파학회JEES 2017 Journal of Electromagnetic Engineering and Science Vol.17 No.4

A new approach to designing a broadband and highly efficient class-E power amplifier based on nonlinear shunt capacitance analysis is proposed. The nonlinear shunt capacitance method accurately extracts optimum class-E power amplifier parameters, including an external shunt capacitance and an output impedance, at different frequencies. The dependence of the former parameter on the frequency is considered to select an optimal value of external shunt capacitor. Then, upon determining the latter parameter, an output matching network is optimized to obtain the highest efficiency across the bandwidth of interest. An analytical approach is presented to design the broadband class-E power amplifier of a MOSFET transistor. The proposed method is experimentally verified by a 140–170 MHz class-E power amplifier design with maximum added power efficiency of 82% and output power of 34 dBm.

Fostering Franchising Intention of SMEs in Vietnam: A Motivation-Opportunity-Ability Perspective

Ninh Thuy TRUONG-THI 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.4

Franchising is one of the most interesting areas of management research, attracting researchers and practitioners from all over the world. Many factors that drive franchising intention have been identified by previous researchers. They also demonstrated that there are numerous research gaps in this subject that must be filled. The primary goal of this study is to identify and test new factors of franchising intent. Finally, to clarify the role of these components, this study used the Motivation - Opportunity - Ability paradigm. To test the hypothesis, SmartPLS software was used to evaluate a total of 252 valid questionnaires collected from small and medium businesses in Hanoi, Vietnam. The findings revealed that franchisee motivation, franchisor support, and asset specificity have a positive impact on franchising intention. In whatever case, the opportunity has the greatest impact on participation intentions. In terms of the impact level on SMEs’ intentions in the franchise system, ability comes in second. Furthermore, the moderating influence of franchisee asset specialization in the relationship between opportunity and franchising intention is confirmed by this study. This study examines the theoretical and practical contributions, as well as their limitations, and suggests some future research on the subject.

Hybrid Multipath Routing in Mobile Ad Hoc Networks

Ninh Khanhchi,정수환(Souhwan Jung) 大韓電子工學會 2011 電子工學會論文誌-TC (Telecommunications) Vol.48 No.2

VANET 응용 중 가장 중요한 한 가지는 긴급 메시지를 전송하여 적극적인 안전을 제공하는 것이다. 메시지를 받은 아무 노드나 재방송하게 되는 플러딩 기반 방송 방식의 브로드캐스트 스톰을 방지하기 위해, 기존의 프로토콜들은 중계노드의 수를 제한하기 위한 다른 방법을 사용한다. 하지만 기존의 프로토콜들은 높은 트래픽 밀도와 메시지 오버헤드를 발생시킴에도 볼구하고 낮은 전달율을 가진다. 현재, 글로벌 위치확인 시스템(GPS)을 내장하고 레이더를 갖춘 차량 수의 극적인 증가는 이전에 볼수 없던 새로운 응용 시나리오를 만들었다. 따라서 우리는 GPS위치정보와 레이더를 사용한 인근 차량 감지를 기반으로 중계노드를 선택하는 브로드캐스팅 프로토콜을 제안한다. 시뮬레이션 결과에서는 제안하는 프로토콜이 기존의 기법들보다 나은 성능을 가짐을 볼 수 있다. One of the most important VANET applications is providing active safety by broadcasting emergency messages. In order to prevent broadcast storm of flooding-based broadcasting scheme in which any node receiving message will rebroadcast, the existing protocols use the different methods to limit the number of relay nodes. Nevertheless, the existing protocols have low delivery ratio with high traffic density and cause message overhead. Currently, the dramatic increase in the number of vehicles equipped with Global Positioning System (GPS) and onboard radar created new application scenarios that were not feasible before. Consequently, we proposed a broadcasting protocol that selects relay node by using GPS-based position information and detecting neighboring vehicles with the help of onboard radar to. Simulation results show that our proposed protocol has better performance than the existing schemes.

Bank Credit, Trade Credit and Growth of Listed Agricultural Firms in Vietnam

Ninh Khuong LE,Anh Tuan BUI,Tu Anh PHAN 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

This paper investigates the relationships between bank credit and trade credit with profit of 130 agricultural firms listed on Vietnam’s stock exchanges during the period 2008-2014. Using the GMM approach, the paper reveals inverted-U shaped (∩) relationships between bank credit and trade credit with profit. Specifically, the optimal threshold of bank credit and trade credit to total assets of the firms are 0.4173 and 0.2425, respectively. The findings mean that if the ratio of bank credit to total assets exceeds the benchmark of 0.4173, firms should consider restructuring debts to get them back to the benchmark. To do so, firms should withdraw from those business fields that are not of their profession, in addition to liquiditizing unused assets to repay debts and not using short-term credit to invest in long-term projects. Firms may use trade credit wisely when other sources of finance are lacking. In concrete terms, firms can increase trade credit use if the ratio of trade credit to total assets is below 0.2425. Yet, if this ratio goes beyond this benchmark, firms should get back to this benchmark, e.g., keeping a suitable amount of inventory. The implications of this study is to boost firm growth in the proposed way.

HYPERSURFACES OF INFINITE TYPE WITH NULL TANGENTIAL HOLOMORPHIC VECTOR FIELDS

Ninh Van Thu 대한수학회 2017 대한수학회지 Vol.54 No.4

In this paper, we introduce the condition $(\mathrm{I})$ (cf. Section \ref{S5}) and prove that there is no nontrivial tangential holomorphic vector field of a certain hypersurface of infinite type in $\mathbb C^2$.

Credit Rationing and Trade Credit Use by Farmers in Vietnam

Ninh Khuong LE,Tu Anh PHAN,Hon Van CAO 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.4

The purpose of this paper is to estimate the impact of credit rationing on the amount of trade credit used by farmers in Vietnam. This study employs a survey data collected through direct interviews with heads of 1,065 rice households randomly selected out of provinces and city in the Mekong River Delta (MRD). In each province or city, the village with the largest area of land devoted to rice production from the district with the largest area of land devoted to rice production was picked up for survey. In each village, 200 rice farmers were randomly chosen for interview. Based on a probit model and a semi-parametric propensity score matching (PSM) estimator while controlling sociodemographic traits of rice farmers, the estimated results show that non-credit rationed farmers use less trade credit to finance production compared to their credit rationed counterparts. Moreover, the amount of trade credit used by farmers decreases as the degree of credit rationing drops. This paper provides evidence of the substitutive relationship between bank credit and trade credit. It also implicitly suggests that banks can drive trade creditors out of the market if they manage to solve the problem of information asymmetry and transaction cost.

Identification of sex-specific SNPS in burbot Lota lota using RAD sequencing: conservation and management applications

Ninh V. Vu,Daniel L. Eardley,Thomas A. Delomas,Matthew R. Campbell 한국수산과학회 2019 Fisheries and Aquatic Sciences Vol.22 No.3

The development of sex-specific genetic assays in a species provides both a method for identifying the system of sex determination and a valuable tool to address questions of conservation and management importance. In this study, we focused on the identification of single nucleotide polymorphisms (SNPs) that differentiate genetic sex in burbot Lota lota. Burbot are the only true freshwater representative of the cod family and a species of conservation and management importance throughout Eurasia and North America. To identify sex-specific SNPs, we utilized restriction site-associated DNA sequencing (RADseq) to interrogate thousands of SNPs in burbot samples of known phenotypic sex. We discovered 170,569 biallelic SNPs, none of which fit the pattern expected under female heterogamety. However, we identified 22 SNPs that fit the pattern expected under male heterogamety (males heterozygous XY, females fixed XX) and, from these, developed two genetic assays that robustly (~ 97% genotyping success) and accurately (> 99% correct) sexed burbot samples. These sex-specific genetic assays will benefit growing conservation aquaculture programs for this species and allow future assessments of sex-specific migration, growth, and mortality.

Analysis in phenolic contents between healthy and viroid-infected apples using HPLC-PDA-ESI-MS/MS

Ninh Khac Thanh Tung,Thi Phuong Duyen Vu,In Sook Cho,Kyung Tae Kim,Seo Young Yang,Young Ho Kim,Hyung Min Kim,Jong Seong Kang 한국분석과학회 2021 학술대회논문집 Vol.2021 No.11

Apples (Malus domestica Borkh.) are one of the most popular fruit in Korea which have played a significant economic role in the agricultural field. Recently, widespread of virus and/or viroid infection in apples had serious impact in Korea which affected the qualities of apples. This study compared healthy and viroid apples in three apple cultivars (Fuji, Gamhong and Hongro) by HPLC. Eleven compounds in apple peels were identified and quantified using HPLC-PDA-MS/MS and HPLC-UV at 280 nm. Analysis condition was optimized using mobile phase of 0.5% acetic acid in water (A) and methanol (B) with a gradual increase of 15% to 60% B for 60 minutes. Significant increases in the level of dihydrochalcones (in all three cultivars), hydroxycinnamic acid (in "Fuji"), and flavonols (in "Hongro") were detected in response to viroid infection. Additionally, the flavonol concentration of "Fuji" viroid-infected samples was significantly decreased. For the discrimination between healthy and viroid-infected samples, researchers developed an excellent linear discriminant model with 98.2% accuracy and 94.6% predictive capacity. The developed method can be used to identify viroid-infected apples and assess their quality.