Temperature history of very small interstellar dust particles is followed under diffuse interstellar radiation. Because of extremely small thermal capacities of these grains with sizes ranging from a few tens to hundred Angstroms in radii, they are to experience strong fluctuations in temperature whenever they are hit by interstellar ultraviolet photons. Fluctuating temperature can inhibit these smaller component of interstellar dust from growing into core-mantle particles of submicron sizes by continuously evaporating atoms and molecules adsorbed on their surface. This is interpreted as a possible physical reason for the bimodal nature in grain size distribution. A brief discussion is also given to the far infrared emission properties of such small grains in diffuse interstellar dust clouds.

A hydrostatic model atmosphere of a typical umbral core is constructed on the basis of both Na I D 2 line profile and umbral core-to disk continuum intensity ratio. The observations were obtained by Mullan and Wyller with photoelectric means over the range from 4000 |AA a n d 6500 |AA . The computed line profile of Na I D 2 and the emergent continuum intensity distribution are compared with the observations. The temperature of umbral cores is found to be lower by 300 ˚ K t o 500 ˚ K than that of their ambient umbral region. The detailed physical structure of a working model of umbral cores is proposed.

The evolutionary tracks of a protostar of one solar mass under quasi-hydrostatic equilibrium are computed with mass-accretion time scales of 10^3,10^4,10^5 and 10^6 years, and their resulting behaviors in the H-R diagram are discussed. It is found that there exists a critical time scale of mass accretion, which reverses the course of their evolutionary tracks. A value of the critical time scale appears to lie between 10^3 and 10^4 years. The physical cause for the presence of the critical time scale is discussed. Finally, it is proposed that star formation requires at least several 10^3 years before any star is born out of dark dense interstellar clouds.

he translational and reactive parts of thermal conductivity of a partially ionized solar magneto-plasma gas have been calculated based on Yun and Wyller's formulation (1972) along with Devoto's theory(1968). The computed results are presented as functions of temperature and pressure for given magnetic field strengths. The results of the calculations show that for most photospheric conditions the magnetic field does not play any important role in characterizing thermal properties of the ionized gas. However, when the gas pressure is low(e.g., P<10 dynes/ c m 2 ) ) the field becomes extremely effective even if its strength is quite small (e.g., B<0.1 gauss). The reactive part of the thermal transport is found to be very important when the gas is undertaking active ionization.

벼를 가해하는 4종의 멸구매미충 즉 애멸구, 끝동 매미충, 벼멸구 및 흰등멸구의 경제적 중요성에 대한 지역적 차이를 수원과 남부 그리고 남서 해안지역에서 수행한 개체군의 밀도조사를 토대로 분석 검토하였다. 한국에서 년중 볼 수 있는 애멸구와 끝동 매미충의 경제적 중요성은 중부지방이 덜한 것으로 보인다. 이는 겨울의 추운 기후조건, 벼, 보리의 경작 방법 및 거미류 같은 천직에 의해서 지연 치사작용이 효과적으로 일어나는 때문인 것으로 믿어진바. 그러나 남부지방에서는 겨울이 덜 춥고 벼, 보리의 경작방법이 이 두 해충의 생활환과 기주식물의 계절적 변천 양자의 재일성에 유리한 편이어서 이들의 경제적 중요성은 확실히 크다고 하겠다. 한국에서 원동을 하지 못하는 벼멸구와 흰등멸구의 매년 첫 발생개체군은 동지나해를 건너 원거리를 이동해 오는 것들에 기인된다. 이들의 이동과 관련을 갖고 있는 기상요소로 해서 이동되어오는 벼멸구와 흰등멸구의 양은 중부지방보다 남부지방에서 월등히 많다. 그러므로 벼를 가해하는 멸구매미충류에 대한 종합방제책으로 중부와 남부지방 별로 지침을 달리 세울 것이 요망된다.

Solar electrical conductivity has been calculated, making use of Yun and Wyller's formulation. The computed results arc presented in a tabulated form as functions of temperature and pressure for given magnetic field strengths. The results of the calculation show that the magnetic field does not play any important role in characterizing the electrical conductivity of the ionized gas when the gas pressure is relatively high (e.g., P ≥ 10 4 d y n e s / c m 2 ). However, when the gas pressure is low (e.g., P ≤ 10 d y n e s / c m 2 ), the magnetic field becomes very effective even if its field strength is quite small (e.g., B ≤ 0.01 gauss). It is also found that, except for lower temperature region (e.g., T ≤ 10 4 ∘ K ), there is a certain linear relationship in a log- log graph between the pressure and the critical magnetic field strength, which is defined as a field strength capable of reducing the non-magnetic component of the electrical conductivity by 20%.

Observational implication for a possible presence of a magnetic monopole-like field in the visible layers of sunspots is examined by constructing a magnetostatic model of sunspots with a monopole-like field configuration. The resulting monopole approximation for a magnetic structure of spots is found to be compatible with the observations within a certain limited range of optical depth, which happens to lie mostly in its visible range.

The earlier findings on the radiative heating through the umbral walls in large sunspots are further investigated. No significant evidence for the umbra! heating has been found in small-sized sunspot umbrae.

Project manager plays a very important role in the success of any project. The primary duty of the project manager is to combine the outcomes or results of the various processes and activities of project management into a systematic project management strategy or plan for the project. In the construction industry, a lack of motivation is an urgent problem for many project managers in construction and engineering projects. Lack of motivation affects the quality and productivity of jobs, reducing profits and growth for companies, businesses, contractors or organizations that rely on human resources. The reasons for this lack of motivation are diverse ranging from salary to culture to life and working environment, among others. Through surveys and data analysis using Cronbach’s Alpha reliability and EFA (Exploratory Factor Analysis), our research scaled the factors affecting work motivation of project managers in the construction industry in Vietnam. The research results identified six major groups of relevant factors including (i) salary and benefits, (ii) work environment, (iii) promotion opportunities, (iv) organizational culture, (v) interest in the job, and (vi) relationship with the organization. From there, this paper contributed useful information as well as measures for businesses, companies, contractors or organizations in the construction industry.

Information transparency ensures that market players all have the opportunity to access the same information to come up with their assessment of the banks’ financial situation, performance and risks to reach effective investment decisions. This research is conducted to investigate the levels of impact of determinants on information transparency by examining the case studies of Vietnamese commercial banks. This study combines both qualitative and quantitative research methods, based on interviews of 32 specialists in banking, accounting and auditing fields, which were conducted to explore determinants influencing information transparency and to develop measurement scales. Then, a survey of 160 managers of commercial banks, audit firms, and accounting managers of firms who frequently had transactions with banks was carried out to investigate the statistical significance of these determinants. The results show that, out of seven determinants that have significant impacts on the banks’ information transparency, commitment from banks’ senior management regarding transparency in information disclosure has the highest impact, followed by state governance, auditing, information infrastructure, credit rating agencies, personnel and bank performance. Accordingly, we provide some recommendations for improving information transparency in the Vietnamese banking industry context as a case study and in emerging countries context in general.

Employability has recently become the first target of the national higher education. Its model has been updated to catch the new trend of Industry 4.0. This paper aims at analyzing and ranking the determinants of undergraduate employability, focusing on business and economics majors in Ho Chi Minh City, Vietnam. In-depth interviews with content analysis have been primarily conducted to reach an agreement on a key group of factors: human capital, social capital, and identity. The Stochastic Fractal Search Algorithm (SFSA) is then applied to rank the sub-factors. Human capital is composed of three major elements: attitude, skill, and knowledge. Social capital is approached at both structural and cognitive aspects with three typical types: bonding, bridging, and linking. The analysis has confirmed the change of priority in employability determinants. Human capital is still a driver but the priority of attitude has been confirmed in the contemporary context. Then, social capital with the important order of linking, bridging, and bonding is emphasized. Skill, knowledge, and identity share the least weight in the model. It is noted that identity is newly proposed in the model but a certain role has been found. The findings are crucial for education strategies to enhance university graduate employability.

Although networking behavior is an effective job search method to students, far too little attention has been paid to mechanisms explaining the antecedents and networking behavior. The goal of this study was to demonstrate the effect of the HEXACO personality dimensions on graduated students’ job search networking behavior through their network size. A survey of 773 participants was conducted to assess personality traits, network size, and networking behavior. All constructs in the study were measured by 5-point Likert scales. This study employed a structural equation model to examine the proposed conceptual model and the correlations among variables. Results showed that the personality of emotionality negatively influence students’ network size, while extraversion and agreeableness are positively associated with the scope of their social network. Second, the findings confirmed that network size is directly related to the level of looking-for job behavior, particularly networking behavior. Finally, our results explored that network size played the mediating effect on how personality traits affect networking behavior. These findings suggest that network size is a dynamic mechanism that helps to understand the correlation between personality traits and job search networking behavior. The theoretical and practical implication of the study, as well as the future research direction were discussed.

The study aims to investigate the dual effects of corruption control on economic growth in relationship with the stock market and trade openness in developing countries. The study used difference S-GMM method on the dynamic panel data model in the period (2002-2017) with data collected from the World Bank. The study discovers the dominant impacts of corruption control in the relationship with the stock market on economic growth. At the same time, the study also confirms the overwhelming impact of corruption control in the relationship between trade openness and economic growth in the developing countries. In addition, the study shows that inefficient stock markets in developing countries will not promote economic growth. Meanwhile, the long-standing credit market has a positive impact on economic growth. With the strong development of stock market and trade openness in the period (2002-2017), control on corruption in developing countries does not get better in time with the increase in demand. The findings of this study suggest a number of solutions to strengthen corruption control, leading to the increased efficiency on the stock market and as well as encouraging the positive effects of trade openness to contribute to promoting economic growth in developing countries.

The research purpose of the article is to evaluate the effects of the internal control components on the effectiveness of internal control of transport construction enterprises in Vietnam, on the basis of which we made recommendations to contribute to improving the effectiveness of internal control. Sample was collected from Vietnamese medium and large transport construction enterprises, the total number of sample questionnaires sent was 400, 330 filled-up questionnaires was collected and 250 was used for the study purpose. Quantitative research method was used for the study with the help of the SPSS software. The variables in the model are as follows: the dependent variable is the effectiveness of internal control, 5 independent variables are: control environment, risk assessment, control activities, communication, and monitoring. The results of the analysis explain 80.4% variation as a result of the effect of internal control on the Vietnamese transport construction enterprise. All five components positively affect the effectiveness of internal controls in the order of influence, which are: control activities, control environment, communication, risk assessment and monitoring. This study contributes in providing more empirical evidence about the effects of internal control components on the effectiveness of internal control of transport construction enterprises in Vietnam. The study has proposed a number of recommendations to help transport construction enterprises improve control activities and contribute towards improving the effectiveness of internal control.

The shift from elite education to mass education in Vietnam has met the demand for education for everybody as well as for quality human resource talent for an emerging nation. Under the resource constraint, understanding the quality dimensions of education and its priority level is important for effective and efficient policies. This study was carried out using both qualitative and quantitative methodologies to develop quality criteria and a ranking model. Two rounds of in-depth interviews were conducted with fifteen experts in the field, who were rectors, employers, and recruitment specialists to develop the quality framework applied in Vietnamese universities under total quality management (TQM), starting from the input of the senior secondary school leavers, through a teaching process to the output. The first round of interviews were unstructured questionnaires designed to explore the main factors in quality assessment model. The second round affirmed the experts’ agreement on the assessment model. Then, fuzzy logic was applied to rank eight criteria in the quality assessment model into priority order: cost, teaching and administrative staff, leadership, curriculum, student-related factors, internationalization, admissions, and campus. The results are critical for identifying the necessary actions to enhance the education quality and to further research on the optimal quality model.

This study measures the relationship between labor productivity and national competitiveness. Through the shift- share analysis method, the paper has separated labor productivity into three factors: static shift effect, dynamic shift effect and endogeneous effect. Next, in combination with the Granger causality test, the paper examines the relationship between the factors constituting labor productivity and competitiveness during the period from 2005 to 2017. Research data is collected from General Statistics Office and annual global competitiveness reports. The results show that the interaction between labor productivity with global competitiveness index (GCI) in Vietnam has similar variation. Nevertheless, when separating labor productivity into three effects, this relationship shows more clearly that the impact of labor productivity on GCI scores is mainly caused by endogeneous effect, not by static shift effect or dynamic shift effect. Therefore, in order to improve its competitiveness, Vietnam should focus on a number of solutions: reforming the education system towards developing thinking capacity and creative capacity; fostering industrial manners to create dynamic and flexible workers; building the State with sufficient capacity to implement consistent and transparent policies; formulating policies to attract all economic sectors so that they actively participate in the field of human resource training for the country.