• Kyungpook Mathematical Journal
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• v.63 no.4
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• pp.521-537
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• 2023

A module M is called a simple-direct-injective module if, whenever A and B are simple submodules of M with A ≅ B and B is a direct summand of M, then A is a direct summand of M. Some new characterizations of these modules are proved. The structure of simple-direct-injective modules over a commutative Dedekind domain is fully determined. Also, some relevant counterexamples are indicated to show that a left simple-direct-injective ring need not be right simple-direct-injective.

• Honam Mathematical Journal
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• v.19 no.1
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• pp.139-144
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• 1997

In this paper, we make some results on the direct limit of the locally nilpotent direct system. We study the ($T^{**}$) - properties of the above direct limit and homotopy equivalence of the direct limits.

• Kyungpook Mathematical Journal
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• v.49 no.4
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• pp.725-729
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• 2009

Let X be a direct system of topological spaces and X its direct limit. We show that under certain conditions the direct limit of a "subsystem" of X embeds in a canonical way as a closed subspace of X.

• Geomechanics and Engineering
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• v.9 no.5
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• pp.601-618
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• 2015

Soil-reinforcement interaction mechanism is an important issue in the design of geosynthetic reinforced soil structures. This mechanism depends on the soil properties, reinforcement characteristics and interaction between these two elements (soil and reinforcement). In this work the shear strength of sand/geotextile interfaces were characterized through direct and simple shear tests. The direct shear tests were performed on a conventional direct shear device and on a large scale direct shear apparatus. Unreinforced sand and one layer reinforced sand specimens were characterized trough simple shear tests. The interfaces shear strength achieved with the large scale direct shear device were slightly larger than those obtained with the conventional direct shear apparatus. Notwithstanding the differences between the shear strength characterization through simple shear and direct shear tests, it was concluded that the shear strength of one layer reinforced sand is similar to the sand/geotextile interface direct shear strength.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.2
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• pp.157-168
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• 2020

Since the economic crisis sweeps across the world in 2008, the foreign direct investment of various countries has been greatly impacted. Therefore, this paper regards China as an example to analyze China's outward foreign direct investment patterns in terms of Asian financial markets with a panel data over the period 2003-2017. We mainly focus on the money market oriented outward foreign direct investment and foreign exchange market oriented outward foreign direct investment. Using the individual fixed effect model to conduct empirical analyses, the empirical findings indicate that China will reduce its foreign direct investment amount to a country with large money supply and China will increase its foreign direct investment amount to a country with large foreign exchange reserves. Furthermore, when a country has signed Free Trade Agreement with China, China will increase more foreign direct investment amount to these countries than that of a country who has not signed Free Trade Agreement with China. Moreover, the empirical findings indicate that no matter what the money market oriented outward foreign direct investment or foreign market oriented outward foreign direct investment, China will reduce its foreign direct investment amount to these Asian countries due to the global economic crisis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.335-338
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• 2000

The technology of direct-seeding in rice cultivation is an innovation mainly induced by factors in market economy and is rapidly diffused among individual farmhouses. Because the effect of technology can be affected by many factors under various farming circumstances, the impact and stability of the direct-seeding technology compared with transplanting was analyzed under various topographical regions. Yield in direct-seeding was higher in plains, although the farm size producing higher yield was quite different depending on the topographical regions. In the direct-seeding cultivation of rice, man-labor hours was reduced by about 38 percent and the reduction rate showed little difference among topographical regions. Fertilizer was used about 11 percent more but the increase rate varied from 3 to 17 percent depending on regions with higher rates in plains. Application of agricultural chemicals was also increased about 9 percent in direct-seeding, but the increase rate was as high as 12 percent in suburbs. More fertilizer and agricultural chemicals were used in direct-seeding cultivation by farmhouses implementing both direct-seeding and transplanting than by those implementing direct-seeding only. Use of more fertilizers and agricultural chemicals in direct-seeding in all regions may indicate its technical instability. Major problems causing the technical instability of direct-seeding cultivation should be solved by comprehensive research considering various farming circumstances such as topographical features rather than just a top-down style research and extension.

• Honam Mathematical Journal
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• v.45 no.2
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• pp.269-284
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• 2023

In this paper we study generalizations of the concept of pure-direct-projectivity from module categories to Grothendieck categories. We examine for which categories or under what conditions pure-direct-projective objects are direct-projective, quasi-projective, pure-projective, projective and flat. We investigate classes all of whose objects are pure-direct-projective. We give applications of some of the results to comodule categories.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.264-268
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• 1998

The experiment was conducted to clarify irrigation requirement and percolation rate in rice paddy. The four rice cultural system of no-tin, till, transplanting, and direct seeding condition were treated in the lysimeter filled with sandy loam soil. The amounts of irrigation and soil percolation were measured daily, and irrigation requirement was estimated. The daily percolation was 19.5 l/$\textrm{m}^2$ in no-till direct seeding on flooded paddy surface, 17.4 l/$\textrm{m}^2$ in both of till-direct seeding on flooded surface and no-till transplanting, and 15.2 l/$\textrm{m}^2$ in transplanting plot. This is equivalent to 19.5, 17.4, and 15.2 mm per day, respectively. Highest irrigation requirement was 3,770 l/$\textrm{m}^2$ in no-till direct seeding plots. Others were 3,249, 2,577, and 2,321 l/$\textrm{m}^2$ in till-direct seeding, no-till transplanting and transplanting plot, respectively. The estimated irrigation requirement of no-till transplanting, till-direct seeding and no-till direct seeding was increased by 11, 37, and 59% compared to till-transplanting plot. Percolation rate of no-till transplanting, till direct seeding and no-till direct seeding was increased by 12%, 40%, and 66%, respectively compared to the till-transplanting plot. The percolation rate in paddy soil was increased greatly after reproductive stage of rice.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.3
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• pp.445-454
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• 1994

Osseointegrated implant prostheses are to provide normal function without compromising the unique interaction between the tissue and the implant. The essential requirement for the osseointegrated implant prostheses is passive fit of abutment. Therefore, the impression must be accurate and reproduciable since the resultant master cast precisely duplicates the clinical condition. The purpose of this study was to compare the accuracy of the master casts obtained from five impression techniques. Group 1 : To take impression with indirect technique and Impregum F. Group 2 : To take impression with unsplinted direct technique and Impregum F. Group 3 : To take impression with splinted direct technique and Impregum F. Group 4 : To take impression with unsplinted direct technique and Xanthano. Group 5 : To take impression with splinted dierct technique and Xanthano. The results were as follow : 1. In taking impression of Impregum F, there was no significant difference between to use of indirect technique and unsplinted direct technique.(p<0.05) 2. Unsplinted direct technique with Impregum F is less accurate than splinted direct technique with Impregum F or Xanthano and unsplinted direct technique with Xanthano.(p<0.05). 3. There was no significant difference between splinted direct technique with Impregum F and unsplinted direct technique with Xanthano.(p<0.05) 4. Splinted direct technique reproduce more accurate than unsplinted direct technique.(p<0.05) 5. Impression plaster produced less distortion than polyether.(p<0.05) As a result, splinted direct technique with Xanthano was the most accurate technique. As a result, splinted direct technique with Xanthano was the most accurate technique in this study. In addition to dimensinal changes in the materials used, positional errors were also attributed to the mechanical components used in the transfer porocess. Although the errors measured were relatively small, this study demonstrates the potential for distortions with the transfer technique used. Further study is indicated that ?the technique will be able to reproduce the intraoral relationship of implant fixtures reliably and predictably.

• The Journal of Industrial Distribution & Business
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• v.12 no.2
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• pp.29-40
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• 2021

Purpose: In this study, with the transaction amount of foreign direct Purchase and foreign direct sales increasing, South Korea is in a situation where foreign direct sales are focused on China. We looked at the impact of consumer innovation and site characteristics on repurchase ability among the characteristics of overseas direct purchase consumers as a way to make direct overseas sales to various overseas countries. Research design, data and methodology: Consumer innovativeness consists of four variables: functional, hedonistic, social, and cognitive, and the site characteristics consisted of four variables: product price, product assortment, convenience, and service. The study was conducted on consumers with foreign direct purchase experience, and was finally used in 252 additional analyses. Results: The main findings of this study were first, that the impact on the degree of re-purchase among consumer innovativeness of foreign direct purchase consumers had a significant impact in the order of cognitive innovativeness, hedonistic innovativeness, and functional innovativeness. Social innovativeness did not affect the degree of re-purchase. Second, site characteristics have been found to have a significant impact on the degree of re-purchase in order of product assortment, commodity price, and service. Convenience did not affect the degree of re-purchase. Conclusions Taken together these results can be called the biggest characteristic of the cognitive innovativeness of the consumer's inclination to use the overseas direct purchase, the price or quick response of the goods sold on the site is a factor that affects the re-purchase, above all it is important to have a variety of products. We will present this element as a way to make direct sales abroad to various countries. In addition, foreign direct purchase is a lot of transactions in China, the United States, EU, but the share of China is high in foreign direct sales, and the U.S. and EU have a very low performance, it is important to consider the reasons why they prefer Korean products in China to study the social and cultural characteristics of U.S. and European consumers in the future, and to support and active marketing that companies and sellers can increase sales.