• Journal of the Korean Mathematical Society
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• v.50 no.6
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• pp.1183-1198
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• 2013

We will introduce and study the notion of prime bases for weakly prime submodules and utilize them to derive some formulas on the weak radical of submodules of a module. In particular, we will show that every one dimensional integral domain weakly satisfies the radical formula and state some necessary conditions on local integral domains which are semi-compatible or satisfy the radical formula and also on Noetherian rings which weakly satisfy the radical formula.

• Journal of Agricultural Extension & Community Development
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• v.4 no.1
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• pp.165-173
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• 1997

This paper reviewed the legal bases and characteristics of agricultural extension services and organizational changes during the last fifty years in Korea. It was found that the legal bases extension services were rather weak are very important factors affecting agricultural extension services and organizational structures of agricultural extension institutions. It would be necessary to take legal steps to strengthen agricultural extension services by institute legal proceedings the characteristics of extension organization including the relationships among central, provincial and county level extension services, missions and objectives, personnel and facility management.

• YAKHAK HOEJI
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• v.41 no.3
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• pp.283-293
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• 1997

Some analogs and their Mannich bases of Antineoplaston A10 (A10) were synthesized. Chemical yield for the 2-(or 3-)thienyl, benzol, and phenylpropionyl analogs were high but 1-naphthyl analog was synthesized in low yield. The Mannich bases formation of these analogs with morpholine went verywell compared to other bases. 1-Naphthyl, 4-nitrobenzoyl, and phenylpropionyl analogs of A10 showed weak in vitro activity but the other A10 analogs showed weaker or no activity at 10-1000mcg/ml. But their Mannich bases containing A10analogs showed good in vitro activity compared to simple A10 analogs.

• YAKHAK HOEJI
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• v.5 no.1
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• pp.20-23
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• 1960

The study of the isolative determination of the mixed weak bases of INAH and NA-Pas potentimetrically considering the properties of solvents for the INAH and Na-PAS, dielectric constant and solvative properties of solvents are described. The methanol: dioxan (4:1) and glacial acetic acid: dioxan (4:1) are studied first as the mixed solvent, using the N/10 perchloric acid and glacial acetic acid solution as the titrant. The authors found that there is no inflection on INAH with the methanol: dioxan solvent system and on Na-PAS at glacial acetic acid dioxan solvent system. By applying methanol glacial acetic acid dioxan (1:1:1) solvent system, Na-PAS and INAH were successfully determined isolatively from the mixed sample, showing the distinguished inflections respectively as shown in the titration curves in figures 3 and 4. It is found that this method could save considerable time for the isolative determination of the mixed sample of week bases as Na PAS and INHA which were quite difficult to be determined by the present routine at control laboratory.

• Bulletin of the Korean Mathematical Society
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• v.46 no.2
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• pp.245-253
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• 2009

A new hard problem called the vector decomposition problem (VDP) was recently proposed by Yoshida et al., and it was asserted that the VDP is at least as hard as the computational Diffie-Hellman problem (CDHP) under certain conditions. Kwon and Lee showed that the VDP can be solved in polynomial time in the length of the input for a certain basis even if it satisfies Yoshida's conditions. Extending our previous result, we provide the general condition of the weak instance for the VDP in this paper. However, when the VDP is practically used in cryptographic protocols, a basis of the vector space ${\nu}$ is randomly chosen and publicly known assuming that the VDP with respect to the given basis is hard for a random vector. Thus we suggest the type of strong bases on which the VDP can serve as an intractable problem in cryptographic protocols, and prove that the VDP with respect to such bases is difficult for any random vector in ${\nu}$.

• Communications of the Korean Mathematical Society
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• v.27 no.3
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• pp.621-627
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• 2012

Star operations are defined by R. E. Hodel in 1994. In this paper some relations among star operators, sequential closure operators and closure operators are discussed. Moreover, we introduce an induced topology by a family of subsets of a space, and some interesting results about star operators are established by the induced topology.

• Earthquakes and Structures
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• v.13 no.5
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• pp.443-454
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• 2017

When eccentrically braced steel frames (EBFs) are in the desired failure mode, links yield at each layer and column bases appear plastically hinged. Traditional design methods cannot accurately predict the inelastic behavior of structures owing to the use of capacity-based design theory. This paper proposes the use of performance-based seismic design (PBSD) method for planning eccentrically braced frames. PBSD can predict and control inelastic deformation of structures by target drift and failure mode. In buildings designed via this process, all links dissipate energy in the rare event of an earthquake, while other members remain in elastic state, and as the story drift is uniform along the structure height, weak layers will be avoided. In this condition, eccentrically braced frames may be more easily rehabilitated after the effects of an earthquake. The effectiveness of the proposed method is illustrated through a sample case study of ten-story K-type EBFs and Y- type EBFs buildings, and is validated by pushover analysis and dynamic analysis. The ultimate state of frames designed by the proposed method will fail in the desired failure mode. That is, inelastic deformation of structure mainly occurs in links; each layer of links involved dissipates energy, and weak layers do not exist in the structure. The PBSD method can provide a reference for structural design of eccentrically braced steel frames.

• Journal of the Korean Regional Science Association
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• v.10 no.1
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• pp.39-52
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• 1994

This paper primarily aims to analyze the growth rate differentials of the economic activities in chung-Nam area. The research has been undertaken to find out the potentials of the economic activities and economic bases in the area. To analyze the economic potentials of the industries, the study employed the economic Growth Rate Differential Analysis by Henderson which is revised form of Shift-Share Analysis Methods. The research employed the employment data according to the standardized two-digit-classification-system during the period of 10 years from 1981 through 1991. The Growth Rate Differential Analysis calculates Total Growth Differentials which are dicomposed into two parts: Weight Part and Rate Part. Total Growth Differential can be calculated as the difference between national growth rate and regional growth rate by industry. The foundings are as follows: First, the economic bases of Chung-Nam area were found to be very weak, largely depending on primary industries such as agriculture and fisheries. Second, there was a great decline in urban industries in Tae Joeon, Cheon An and other cities over period of 1971-1981. It is strongly recommended that the planned items and products of each industrial complex must be reorgnized in a fashion to match those with high competitive power found in this research.

• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.164-171
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• 2019

The protonation parameters, dissociation constants ($pK_{BH^+}$) of conjugate acid, slope values (m, ${\phi}$ and $m^*$) and correlation coefficients (r) of hydroxamic acids were determined by Hammett acidity function method, Bunnett-Olsen method and excess acidity method in hydrochloric and perchloric acid solutions. Effect of acid concentration on partition and percentage protonation was also studied. $pK_{BH^+}$ values show that hydroxamic acids do not behave as Hammett bases, but hydroxamic acids behave as weak bases in strong acidic solutions. The values of $pK_{BH^+}$ obtained through Bunnett-Olsen method and excess acidity method were compared with the Hammett acidity function. ChemAxon's MarvinSketch 6.1.5 software was also used for determining $pK_a$, pI and microspecies distribution (%) of hydroxamic acids with pH. Hydrogen donor and acceptor values and logD were also obtained. The results show that N-p-chlorophenyl-4-bromobenzohydroxamic acid has the highest $pK_a$ and lowest logD values. On the contrary, N-phenyl-3,5-dinitrobenzohydroxamic acid has lowest the $pK_a$ and highest logD values.

• Journal of Plant Biology
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• v.35 no.4
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• pp.393-401
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• 1992

A new species of Dictyostelium, isolated from the subalpine coniferous forests of Halla mountain, was described. The most noteworthy morphological characteristics of this new species were broad petal-like aggregates, concentrated long branches near the bases, typically clustered and delicate sorocarps. DictyosLeLium jloridurn sp. novo was also characterized by 1) elliptical spores with distinctive polar granules, 2) strongly tapering and rough surface of sorophores, 3) frequent occurrence of expanded conical bases, 4) the congealed slime substrate where the several bases were anchored into, 5) compound and c1avata tips. It was quite sensitive to environmental conditions, particularly temperature. Macrocysts and microcysts were not observed. This species can be cultured satisfactorily in assosiation with Esch'||'&'||'pound;richia coLi upon agar media of weak nutrient content, 0_1% lactosepeptone, under diffuse light and darkness. Optimum temperature for growth and develoi)ment was about $18-22^{\circ}C$, below that of most other species of the family.