검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 216

        163.
        1997.06 구독 인증기관·개인회원 무료
        During sintering of very porous green bodies, as obtained by compaction of hard powders - such as tungsten carbide or ceramics - or by injection moulding, important shrinkage occurs. Due to heterogeneous green density field, gravity effects, friction on the support, thermal gradients, etc., this shrinkage is often non-uniform, which' may induce significant shape changes. As the ratio of compact dimension to powder size is very high, the mechanics of continuum is relevant to model such phenomena. Thus numerical techniques, such as the finite element method can be used to simulate the sintering process and predict the final shape of the sintered part. Such type of simulation has much been developed in the last decade firstly for hot isostatic pressing and next for die compaction. Finite element modelling has been recently applied to free sintering. The simulation of sintering should be based on constitutive equations describing the thermo-mechanical behaviour of the material under any state of stress and any temperature which may arise within the sintering body. These equations can be drawn either from experimental data or from micromechanical models. The experiments usually consist in free sintering and sinter-forging tests. Indeed applying more complex loading conditions at high temperature under controlled atmosphere is delicate. Micromechanical models describe the constitutive behaviour of aggregates of spheres from the deformation of two-sphere contact either by viscous flow or grain boundary diffusion. Such models are not able to describe complex microstructure and mechanisms as observed in real materials but they can give some basic information on the formulation of constitutive equations. Practically both experimental and theoretical approaches can be coupled to identify the constitutive equations. Such procedure has been performed for modelling the sintering of compacts obtained by die pressing of a mixture of tungsten carbide and cobalt powders. The constitutive behaviour of this material during sintering has been described by a linear viscous constitutive model, whose functions have been fitted from results of free sintering and sinter-forging experiments. This model has next been introduced in ABAQUS finite element code to simulate the sintering of heterogeneous green compacts of various geometries at constant temperature. Examples of simulations are shown and compared with experiments.
        164.
        1996.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Multi-wavelength observing has been particularly fruitful in cool star research. There have been some well-observed examples, eg AB Dor, though ambiguity remains. This raises issues of data information content and model parameter determinacy, which are examined firstly in an optical context. We then widen the discussion to show how multi-site and multi-wavelength data can be combined to point to better constrained models. Particular cases, involving near-simultaneous radiometry and photometry, are discussed to clarify such modelling.
        3,000원
        169.
        1992.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A laboratory bioassay that incorporates Bacillus thuringiensis (Bt) purified crystal protein toxins into an artificial diet has identified three toxins, CryIA(b), CryIA(c), and CryIIA, to by effective against the yellow stemborer, Scirpophaga incertulas(Walker). Research is aimed at engineering rice that incorporates genes of one of or more of these toxins so as to mimic the insecticidal action of the insect to Bt. The paper discusses potential strategies for slowing the rate of adaptation that include the use of multiple Bt toxins, promoters that express the toxins only in specific plant tissues at specific times, and mixing transgenic and non-transgenic plants.
        4,000원
        171.
        1992.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present new approach to analysis of velocity data of globular clusters. Maximum likelihood method is applied to get model parameters such as central potential, anisotropy radius, and total mass fractions in each mass class. This method can avoid problems in conventional binning method of chi-square. We utilize three velocity components, one from line of sight radial velocity and two from proper motion data. In our simplified scheme we adopt 3 mass-component model with unseen high mass stars, intermediate visible stars, and low mass dark remnants. Likelihood values are obtained for 124 stars in M13 for various model parameters. Our preferred model shows central potential of W o = 7 and anisotropy radius with 7 core radius. And it suggests non-negligible amount of unseen high mass stars and considerable amount of dark remnants in M13.
        4,000원
        174.
        1985.12 구독 인증기관 무료, 개인회원 유료
        4,000원
        175.
        1977.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        주요 벼 해충의 경제적 피해 수준을 결정하고 약제살포 회수의 감소 가능성을 모색하기 위하여, 수원 등 4개 지역의 농가 포장 조건하에서 본 연구를 수행하였다. 무살포구 관행방제구 및 2.3의 관행 방제를 수정한 처리구를 두었으며, 해충 밀도 및 병의 발생에 대해서도 상세한 기록을 행하였다. I) 이화명충의 제1세대가 활발한 중부지방의 수원과 이천의 경우 수회 약제 살포구와 무살포구 사이의 수량의 차에 유의성이 없었으며, 평균 수량은 높아서 5.2-7.6t/ha였다. ii) 일본형 품종이나 다수성 품종인 통일 어느 품종에서도 수량의 감소를 인정할 수 없었던 고로 피해경율이 까지 상승한 제1세대 유충의 가해행위는 경제적 피해 수준 이하였다. iii) 유충에 의한 피해는 피해경이 대체되는 보상생장에 의해서 호전된다는 증거가 얻어졌다. 이화명충의 제2세대 개체군은 언제나 낮았다. iv) 수원과 이천에서 얻어진 결과를 볼 때 현재의 관행 약제 살포 회수 6-7회는 합당하지 않다. v) 남부지방인 이리의 경우 애멸구에 의한 줄무늬잎 마름병이 초기에 대발생하여 이로 인해 실질적인 수량의 감소가 일어났다. 이앙 직후에 애멸구의 평균 밀도는 주당 1-2마리였다. 이화명충도 이러한 수량의 감소에 영향을 주었을 가능성이 있다. vi) 이리에서 애멸구에 대해 수회의 약제 살포를 행하였으나 감수성 품종에서 급속하게 번져가는 줄무늬 잎마름병을 막을 수 없었으며, 그 주변 포장의 저항성 품종인 통일은 비교적 영향을 받지 않았다. vii) 끝동매미충, 벼멸구, 횐등멸구 및 벼잎굴파리는 중요성이 적은 해충이다.실효를 거둘 수 없는 반면 신문지 봉지는 피해율을 나타냈으나 숙기가 약간 지연되는 외에는 하등의 지장이 없었다. 5) 백색 전구는 비래 나방수가 10.8마리로 청색 0.95마리, 황색 전구 0.22마리에 비하여 많이 비래하였으나 방제효과 면에서는 기대하기가 어려운 것으로 본다의 밀도를 조사였다. 1. Carbofuran, Omethoate 액상근부처리에 비하여 캡슐 근부처리는 이화명충, 애멸구방제효과가 월등히 좋았고 Omethoate보다는 Carbofuran의 방제효과가 좋았다. 2. Carbofuran 1회 액상근부처리는 Carbofuran 2회 수면시용과 대등한 수도해충의 방제효과가 있었다. 3. A포장에서 보다 B포장에서 이화명충 방제효과가 좋았는데 그것은 B포장에서의 약제처리시기가 이화명충 방제적기에 해당하기 때문인 것 같다. 4. Carbofuran 1회 근부처리는 수도 전 생육기간에 걸친 수도해충방제가 가능한 것으로 보였다.이었다. 따라서 양자간의 상관관계를 밝히는데 도움이 되지는 못하였다. 그러나 본 연구기간 중 필자의 주장을 뒷받침 해 주는 중요한 새로운 정보를 입수할 수 있었다. 즉 1946년에 흰둥멸구의 대발생으로 충남, 전남지방에 피해가 심했으며 그중 피해액이 밝혀진 곳은 라주군에서 16만석, 서산군에서 19만석이었다. (당시 농사시험장 곤충담당관 이봉우씨 담, 현재선 교수 전) 1910년 이후의 우리나라에서의 벼멸구 생기록을 보면 항상 흰등멸구와 함께 발생하고 있으며 최근의 예찰등성적을 보아도 함께 나타나 있고, 해에 따라 1975년도와 같이 벼멸구가 대발생하는 수도 있
        4,000원
        176.
        2020.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Work motivation is critical for ensuring sustainability of any business firm. Motivated personnel essentially helps an organization achieve its organizational goal and objective. Hence, it has become an essential duty for business managers and management committees to identify the motivating factors that would strongly affect their employees. The purpose of the current research is to identify which are the factors that motivate service employees most at their workplace in Bangladesh. The study has used survey questionnaires to collect data from service employees. Convenience sampling is used for data collection. A total of 240 questionnaires were distributed and 183 completed questionnaires were returned (response rate: 77%). The study used purposeful motivating factors, which are ranked (from 1 to 10) by the service employees according to the significance of the factors. Mean value is applied to determine the most crucial motivating factor, where the factor with lowest mean value is considered as the highest significant motivating factor. Results reveal that job certainty, career growth and advancement opportunity, and quality working environment have been the most crucial and influential motivating factors for the service employees. The study adequately underlines the necessity of motivational factors and provides some guidelines to keep employees motivated.
        177.
        2020.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study examines simultaneous relationships between regulatory capital, risk, and cost-inefficiency for a sample of 30 commercial banks in Bangladesh from 2006 to 2018. To conduct the analysis, we used the Generalized Methods of Moments (GMM) in an unbalanced panel data framework. The empirical results show that there is a negative and significant relationship between capital regulation and credit, and overall risk. It is also evident from the results that the capital adequacy ratio is positively and significantly related to default risk and liquidity risk. Therefore, higher capitalized banks take an effort to prevent more credit risk and promote financial stability by reducing liquidity risk. Results also report that banks have been characterized as inefficient, less capitalized, and high risk. On the other hand, efficient banks are more stable but have a high level of liquidity risk. Besides, from the size of the bank, large banks are defined as having lower regulatory capital, are more risk seekers but stable with higher cost-efficiency. Notably, higher capitalized banks are more profitable and cost-efficient by reducing risk. Finally, this study also provides some insightful policy suggestions to the stakeholders.
        178.
        2020.11 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This research is a literacy study regarding the implementation and management of the economic role of haria as a new strategy in overcoming the problem of the global financial crisis that has hit the middle of the COVID-19 pandemic. The research method comes from previous studies to compare the capitalist, socialist, and sharia economic systems. In response to various economic uncertainties, both internal and external, the ability to seize opportunities and transform has become the key to economic resilience. Islamic economics can be an alternative in responding to the dynamics of the global and national economy. Several things need to be taken into consideration in fulfilling the sharia economy and the primary strategy chosen must come from the inputs given by the stakeholders, including business actors, associations, regulators as well as experts, and academicians. The primary strategy in implementing the sharia economy also requires the support of various parties in order to develop sustainability. Strengthening regulation and governance is one of the fundamental factors. Optimization of the sharia economy based social sector such as Zakat, Infaq, Sadaqah, and Waqaf can be optimized both for collection and distribution so that the concept of sharing can certainly support the development and the economy both nationally and globally.
        179.
        2020.10 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this competitive era, it has become a prerequisite for the financial firms providing banking services to understand and meet the customers’ needs and demands to remain competitive in today’s market environment. Without satisfying the customers, banking business cannot stand alone. To satisfy customers, it is often recommended to provide better quality banking services to the bank customers. Providing quality banking services has become a prime strategic tool for the banking sector nowadays. Therefore, the study investigates the effect of various dimensions of service quality of banking service on customer satisfaction in a developing country, Bangladesh. A total of 212 walking Bangladeshi banking customers participated in this research. A structured questionnaire was developed based on past research. SPSS is utilized for analysis and Likert scale was used in this study. Internal consistency of all items was found correct and a total of seven hypotheses were proposed. For testing, a 5% significance level is considered for acceptance of hypothesis. The findings show that, except employee competency, all other variables such as reliability, assurance, tangibles, responsiveness, empathy, and access to service have positive influence on customer satisfaction. The study provides policy implications for the management boards of the banking sectors.
        180.
        2020.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Entrepreneurial intention is receiving immense recognition in entrepreneurship researches, as it motives an individual to become an entrepreneur. Still, the interplay between gender perspective and contextual factors (i.e., access to capital, business information, social network, educational support, structural support) are not fully investigated in understanding the entrepreneurial intention in developing countries like Bangladesh. Therefore, the paper aims to examine the gender difference and educational discipline difference in the university’s students’ entrepreneurial intention in relation to contextual factors in Bangladesh. In this study, sample has been particularly taken from the different disciplinary students of private universities. Five-point Likert scale-based survey questionnaire was developed based on past researches. 280 online survey forms were distributed among the university students and finally 225 students’ response were found correct as the study sample size (final survey response rate = 80%), after eliminating the incorrect survey responses. For statistical analysis SPSS 23.0 version is used. One-way ANOVA is used to measure the gender and discipline difference on entrepreneurial intention among male and female students. The results show that business information and social network will have more influence on male students’ entrepreneurial intention, and comparatively, business students have more willingness to become entrepreneurs than other departmental students.