• Journal of the Korean Mathematical Society
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• v.50 no.4
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• pp.847-864
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• 2013

By a change of variables we obtain new $y$-coordinates of elliptic curves. Utilizing these $y$-coordinates as meromorphic modular functions, together with the elliptic modular function, we generate the fields of meromorphic modular functions. Furthermore, by means of the special values of the $y$-coordinates, we construct the ray class fields over imaginary quadratic fields as well as normal bases of these ray class fields.

• Journal of the Chungcheong Mathematical Society
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• v.25 no.1
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• pp.105-113
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• 2012

Generalizing modular lattices, a concept of modular ordered sets was introduced by Chajda and Rachunek. In this paper, we characterize modular ordered sets as those partially ordered set P satisfying that for $a,\;b,\;c\;{\in}\;P\;with\;b\;{\leq}\;c,\;l(a,\;b)\;=\;l(a,\;c)\;and\;u(a,\;b)\;=\;u(a,\;c)$ imply $b\;=\;c$. Using this, we obtain a sufficient condition for them. We also discuss the modularity of the Dedekind-MacNeille completions of ordered sets.

• Communications of the Korean Mathematical Society
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• v.24 no.2
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• pp.181-185
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• 2009

The Drinfeld modular function ${\mu}$ is a generator of the function field of the Drinfeld modular curve $X_0(T)$ and has an t-expansion with the integral coefficients at infinity. In this paper, we show that the coefficients of ${\mu}$ has congruence properties modulo powers of T.

• Bulletin of the Korean Mathematical Society
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• v.46 no.2
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• pp.229-234
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• 2009

We find congruences for the t-expansion coefficients of a Drinfeld modular form for ${\Gamma}^+_0$(Q), where Q is a monic irreducible polynomial. As an application we obtain new congruence relations for the t-expansion coefficients of Drinfeld modular forms for ${GL_2}(\mathbb{F}_q[T])$.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.54-64
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• 2015

The modular construction has several advantages such as high quality of product, safe work condition and short construction duration. The manufacturing planning of modular construction should consider time frame of manufacturing, transport and erection process with limited resources (e.g., modular units, transporter and workers). The manufacturing planning of multi modular construction project manages the modular construction's characteristics and diversity of projects, as a type of modular unit, modular unit quantities, and date for delivery. However, current modular manufacturing planning techniques are weak in dealing with resource interactions and each project requirement in multi modular construction project environments. Inefficient allocation of resources during multi modular construction project may cause delays and cost overruns to construction operation. In this circumstance, this research suggest a manufacturing planning model for schedule optimization of multi project of modular construction, using genetic algorithm as one of the powerful method for schedule optimization with multiple constrained resources. Comparing to the result of the existed schedule of case study, setting optimized scheduling for multi project decrease the total factory producing schedule. By using proposed optimization tool, efficient allocation of resource and saving project time is expected.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.33-41
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• 2017

A modular specification is a contract document that specifies the requirements of production, transformation and installation in a modular construction. A problem of the currently used specification is that it does not guarantee the level of performance required by the modular construction and fails to accommodate unique characteristics of each construction because it widely uses the standard specification as it is. This study proposes a specification that reflects the unique feature of modular construction in order to improve the quality of modular construction. Research focuses on the leakage in waterproof and mechanical equipment because it is the area with the highest rate of defects. This study suggests ways to improve the modular specification as follows: 1)Descriptive specifying (following MasterFormat) 2)Propose leakage verification method and test clause 3) Reflect characteristic of modular construction. Proposed modifications to modular specification are reviewed by experts for validation and their opinion verifies suggested improvements as a way to secure the quality of modular construction and to promise characteristics of the modular specification. This improvement will be used for reference when writing construction project specification, which can be an important contract document, so that it could lower occurrence rate of the modular defects.

• Journal of KIBIM
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• v.5 no.1
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• pp.1-7
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• 2015

Modular technology has become a major issue of the construction industries to enhance their productivity. Modular bridge construction generally requires the data exchange between the contractors, designers, fabricators and constructors. Therefore, a readily accessible information model interface module based on BIM technology is essential for their communication during a project life-cycle. In this study, BIM based information model interface module for a modular pier was developed. For the information models, the PBS(Product Breakdown Structure) and LOD(Level of Development) were defined. Next, all components of a modular pier were conducted by the parametric modeling technique, and then 3D cell library interface was developed. An nterface module was also developed using VBA(Visua basic Application) for exchanging a data from 3D model library to other softwares such as Microstation, AutoCad and Excel and was connected with MS Access database. The developed information model interface module would improve the design quality of the modular pier and reduce the time and cost for design. Updated 3D information models could be utilized for the fabrication, assembly, and construction process for modular piers.

• Journal of the Korean housing association
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• v.23 no.4
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• pp.49-57
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• 2012

This study was conducted to apply the modular construction method to Han-ok. The modular method, which is differentiated from the existing one, means a construction method that equipments, windows and interior materials are prefabricated as a six-sided object at a plant and then they are assembled at the least process on the spot. As for the theoretical observation, the theoretical basis to apply the modular method to the modular housing and Hanok was divided into environmental and economic aspect. In order to apply the modular method to Hanok, the unit scale and size were selected and the plane of unit module Hanok was developed. And a standard with regard to the unit combination and material lifting transportation method was set and planned. In addition, through the comparison the unit modular Hanok to the existing Hanok, the difference was analyzed and the strength was identified in terms fo design method, structure, construction method, period and cost. In final, the conclusion, with regard to the economic, technical application in future, was drawn through arranging the study contents. The unit modular Hanok to carry out the high-quality dwelling through construction period reduction, standardized construction materials and improved insulation performance can meet the demands for a paradigm of new construction technology.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.7
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• pp.743-751
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• 1999

공개키 암호 시스템에서 모듈러 지수 연산은 주된 연산으로, 이 연산은 내부적으로 모듈러 곱셈을 반복적으로 수행함으로써 계산된다. 본 논문에서는 GF(2m)상에서 수행할 수 있는 Montgomery 알고리즘을 분석하여 right-to-left 방식의 모듈러 지수 연산에서 공통으로 계산 가능한 부분을 이용하여 모듈러 제곱과 모듈러 곱셈을 동시에 수행하는 선형 시스톨릭 어레이를 설계한다. 본 논문에서 설계한 시스톨릭 어레이는 기존의 곱셈기보다 모듈러 지수 연산시 약 0.67배 처리속도 향상을 가진다. 그리고, VLSI 칩과 같은 하드웨어로 구현함으로써 IC 카드에 이용될 수 있다.Abstract One of the main operations for the public key cryptographic system is the modular exponentiation, it is computed by performing the repetitive modular multiplications. In this paper, we analyze Montgomery's algorithm and design a linear systolic array to perform modular multiplication and modular squaring simultaneously. It is done by using common-multiplicand modular multiplication in the right-to-left modular exponentiation over GF(2m). The systolic array presented in this paper improves about 0.67 times than existing multipliers for performing the modular exponentiation. It could be designed on VLSI hardware and used in IC cards.

• Journal of Korean Association for Spatial Structures
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• v.21 no.3
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• pp.69-76
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• 2021

Precast concrete (PC) modules have been increased its use in modular buildings due to their better seismic performance than steel modules. The main issue of the PC module is to ensure structural performance with appropriate connection methods. This study proposed a PC modular beam system for simple construction and improved structural and splicing performance. This modular system consisted of modules with steel plates inserted, and it is easy to construct by bolted connection. The steel plates play the role of tensile rebar and stirrup, which has the advantage of structural performance. The structural performance of the proposed PC modular beam system was evaluated by flexural test on one reinforced concrete (RC) beam specimen consisting of a monolithic, and two PC specimens with the proposed PC modular beam system. The results demonstrated that the proposed PC modular beam system achieved approximately 86% of the structural performance compared to the RC monolithic specimen, with similar ductility of approximately 1.06 fold greater.