ON THE STRUCTURES OF CLASS SEMIGROUPS OF QUADRATIC NON-MAXIMAL ORDERS

KIM, YONG TAE The Honam Mathematical Society 2004 호남수학학술지 Vol.26 No.3

Buchmann and Williams[1] proposed a key exchange system making use of the properties of the maximal order of an imaginary quadratic field. $H{\ddot{u}}hnlein$ et al. [6,7] also introduced a cryptosystem with trapdoor decryption in the class group of the non-maximal imaginary quadratic order with prime conductor q. Their common techniques are based on the properties of the invertible ideals of the maximal or non-maximal orders respectively. Kim and Moon [8], however, proposed a key-exchange system and a public-key encryption scheme, based on the class semigroups of imaginary quadratic non-maximal orders. In Kim and Moon[8]'s cryptosystem, a non-invertible ideal is chosen as a generator of key-exchange ststem and their secret key is some characteristic value of the ideal on the basis of Zanardo et al.[9]'s quantity for ideal equivalence. In this paper we propose the methods for finding the non-invertible ideals corresponding to non-primitive quadratic forms and clarify the structure of the class semigroup of non-maximal order as finitely disjoint union of groups with some quantities correctly. And then we correct the misconceptions of Zanardo et al.[9] and analyze Kim and Moon[8]'s cryptosystem.

Articles : Effects of Non-Ideal Adsorption Equilibria of Gas Mixtures on Column Dynamics

( Jeong Ho Yun ),( Dae Ki Choi ),( Sung Hyun Kim ),( Hee Moon ) 한국화학공학회 1997 Korean Journal of Chemical Engineering Vol.14 No.5

A theoretical study has been made for simulating the dynamic behavior of non-ideal gas mixtures in an isothermal fixed-bed adsorber. A mathematical model was developed which takes into account the non-ideality of adsorbable species on the adsorbed phase under equilibrium. The model is based on both the real adsorbed solution theory (RAST), which incorporates the activity coefficients in the multicomponent isotherm equations to account for the deviations from ideality, and the linear driving force (LDF) model for representing diffusion resistance inside the adsorbent particles. To describe the effect of non-ideal adsorption equilibrium of gas mixtures on the breakthrough curves, we considered several model mixtures of binary and ternary components which exhibit non-ideal behavior with azeotropic crossovers in the composition domains at equilibrium. Sample calculations of a fixed-bed adsorption were done with various inlet gas compositions of binary and ternary mixtures, respectively, at a fixed total concentration. From the calculation results, it was shown that the order of breakthrough curves could be changed at a certain value of inlet gas composition ratio. This result implies that the dynamic behaviors of fixed-bed adsorption are greatly influenced by multicomponent equilibrium models. Furthermore, the reversal phenomenon of breakthrough curves could not be simulated by the ideal adsorbed solution theory (IAST).

비주류 음료의 수요탄력성 추정에 관한 연구

김원년,민대홍,제상영 한국자료분석학회 2019 Journal of the Korean Data Analysis Society Vol.21 No.1

Changes in household consumption patterns since the 1990s have had a major impact on the non-alcoholic beverage (coffee, tea, juice·other beverages). The study of the increase of consumption expenditure and the change of expenditure structure is important for judging consumer's desire as well as the level of dietary. In order to analyze the interrelation between non-alcoholic beverage since 2000, this study set four demand equations through linear approximate almost ideal demand system and estimated by seemingly unrelated regression. As a result, the income elasticity was calculated as 0.3363, 0.2494, and 0.4618, respectively and the self-price elasticity was all negative. This means that non-alcoholic beverage was both normal and mandatory for household expenditure items. Also, according to the results of cross elasticity estimated, tea and juice·other beverages complement each other, but coffee is considered as a substitute for tea and juice·other beverages. This is a micro-base of how the economic shock of a detailed item changes aggregate demand. 1990년대 이후 진행된 가계소비 형태의 변화는 비주류 음료(커피, 차, 주스·기타음료)에도 큰 영향을 주었다. 2000년대 이후, 비주류 음료 간 상호관계를 분석하기 위해 본 연구에서는 준이상수요체계모형을 통한 4개의 수요방정식을 설정하고 표면무관회귀방법으로 추정하였다. 그 결과, 커피, 차, 주스·기타음료의 소득탄력성은 각각 0.3363, 0.2494, 0.4618이며, 자기가격탄력성은 모두 음수가 산출되었다. 이는 비주류 음료가 정상재이면서 필수재임을 의미하고, 소비자 이론에도 부합한다. 본 연구에서는 차와 주스·기타음료의 자기가격탄력성의 절댓값이 1을 초과하는 것을 통해 자기가격의 증가로 인한 대체가 매우 탄력적으로 이뤄지고 있음을 확인했다. 또한, 비주류 음료 간 교차탄력성의 추정결과에 따르면 차와 주스·기타음료는 서로 보완하는 관계를 가지고 있었지만, 커피는 차와 주스·기타음료를 대체하는 상품으로 산출되었다. 따라서 차 가격의 증가는 커피의 소비를 증가시키지만 차와 주스·기타음료의 소비는 감소시켰다. 이러한 결과는 비주류 음료의 특성을 제시할 뿐만 아니라 세부 품목에서 발생하는 경제적 충격이 총수요를 얼마나 변동시키는지에 관한 미시적 기초가 된다.

Generalized Prime Ideals in Non-associative Near-rings I

조용욱 영남수학회 2012 East Asian mathematical journal Vol.28 No.3

In this paper, the concept of ∗-prime ideals in non-associative near-rings is introduced and then will be studied. For this purpose, first we introduce the notions of ∗-operation, ∗-prime ideal and ∗-system in a near-ring. Next, we will define the ∗-sequence, ∗-strongly nilpotent and ∗-prime radical of near-rings, and then obtain some characterizations of ∗-prime ideal and ∗-prime radical r_s(I) of an ideal I of near-ring N.

GENERALIZED PRIME IDEALS IN NON-ASSOCIATIVE NEAR-RINGS I

Cho, Yong-Uk The Youngnam Mathematical Society 2012 East Asian mathematical journal Vol.28 No.3

In this paper, the concept of *-prime ideals in non-associative near-rings is introduced and then will be studied. For this purpose, first we introduce the notions of *-operation, *-prime ideal and *-system in a near-ring. Next, we will define the *-sequence, *-strongly nilpotent *-prime radical of near-rings, and then obtain some characterizations of *-prime ideal and *-prime radical $r_s$(I) of an ideal I of near-ring N.

OPTIMAL LINEAR CONTROL APPLIED TO A NON-IDEAL CAPSULE SYSTEM WITH UNCERTAIN PARAMETERS

ROEFERO, LUIZ GUSTAVO PEREIRA,CHAVARETTE, FABIO ROBERTO,OUTA, ROBERTO,MERIZIO, IGOR FELICIANI,MORO, THIAGO CARRETA,MISHRA, VISHNU NARAYAN The Korean Society for Computational and Applied M 2022 Journal of applied mathematics & informatics Vol.40 No.1-2

The design of mechanical structures aims to meet criteria, together with the safety of operators and lives in the vicinity of the equipment. Thus, there are several cases that meeting the desired specification causes the mechanical device to perform unstable and, sometimes, chaotic behavior. In these cases, control methods are applied in order to stabilize the device when in operation, aiming at the physical integrity of the component and the device operators. In this work, we will develop a study about the influence of a controller applied in a non-ideal capsule system operating with uncertain parameters, being non-existent in the literature. For this, two initial conditions were used: one that the capsule starts from rest and another that it is already in motion. Thus, the effectiveness of the controller can be assessed in both initial conditions, restricting the movement of the internal vibration-impact system to the capsule.

통번역 교수자의 제2언어 성취동기 강화 모델 프로그램 개발을 위한 실행연구 - 비원어민 교수자의 L2 성취동기를 중심으로 -

최소영 일본어문학회 2020 일본어문학 Vol.88 No.-

The present article conducts semi-constructive interviews for twenty non- native lecturers working at a Korean university department concerning translation and interpretation and a corresponding department at a Korean graduate school, and analyzes there cognition of language fluency by these teachers and their experiences in connection with the improvement of their Japanese proficiency and motivations for learning. The “future L2 self” of teachers whose Japanese proficiency is quite high consists of three factors in the two academic institutions: self-consciousness of Japanese fluency, identity of a non-native speaker, and motivations for further improving Japanese proficiency. The study indicates that different methods of delivering the knowledge of language are used in different environments and that the range of expressions used itself differs in the two environments. Since changes in fluency essentially form part of language teaching, these different environments, together with learner’s learning preferences, crucially affect teachers.

초고속 구동계의 횡방향강성이 Sommerfeld 현상에 미치는 영향

신세동(S. S. Shin),손명균(S. M. Sohn),신응수(E. C. Shin) 한국생산제조학회 2013 한국생산제조시스템학회 학술발표대회 논문집 Vol.2013 No.4