• Publications of The Korean Astronomical Society
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• v.11 no.1
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• pp.57-73
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• 1996

As a continuing effort to develop an automatic control system for small telescope, we developed the software for telescope control and CCD observations under DOS operating system. For accurate pointing of the telescope in short amount of time, we modelled the angular speed of the telescope by aquadratic function of time (constant acceleration) for the first 15 second and then linear function of time (zero acceleration) aftwewards. By changing the telescope speed from 'slew' to 'fine' before the telescope reaches the desired position, we could achieve the accuracy of a few arcsecond. The CCD control software was written for model CCD-10 of CCD Technology. This CCD can be used for guiding purposes. We also conducted the study for remote control of the telescope using telephone line. Although it cannot be used for real observations at the present form, we succeded in remotely pointing the telescope to desired direction. As faster communication technologies become widely available, simple observations can be made remotely in the near future. Finally we report some observational results made with the present control system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.499-502
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• 2008

This paper presents on research findings of how Visual C++ program can be used to generate codes capable of performing ramjet engine simulation To understand the diversity and applicability of this tool an arbitrary ramjet model will be considered for which generated output values will be compared with those from a commercial program GASTURB 9 iterated under the same input parameters. Several governing thermodynamic equations will first be discussed in order that we understand the fundamental idea behind values printed out on the GUI. C++ compiler was chosen as a tool of use due to its availability, ease of use, ability to compute functions faster and uniquely possible to make a stand alone GUI executable in DOS mode. The program is developed in such a way that given the ambient flight conditions, burner exit temperature and several geometry areas the program generates its own input values used in the succeeding stations. A close resemblance of output values that define performance and thermodynamic state of the engine was realized between GASTURB 9 and using this code made from C++ compiler.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.63-70
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• 1995

Most of small-to-medium sized companies use computer to manage and control their manufacturing system. However, it is real hard to find a company which uses the system properly. There are several reasons. First of all, appropriate software to satisfy user's needs is not available and there is lack of mind to computerize. Therefore, this paper focuses to show difficulties which they will encounter, develop a model of computerized production management system and define proper level of computerization. An experimental system has been developed for an auto-parts manufacturing company using IBM-PC in the environment of MS-DOS and CA-Clipper.

• Journal of the Korean Society for Railway
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• v.6 no.2
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• pp.100-107
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• 2003

This paper presents development of train performance simulation(TPS) program to analyze traction performance, braking performance and energy consumption for Korea high speed railway system. The conventional TPS program have some inconveniences such as DOS-based platform, user interface and limited function. The simulation technique model using scenario menu, various analysis function and object-oriented design/programming is presented. This simulation result have been compared with Alstom's for the Seoul-Pusan High Speed Rail Project.

• Journal of the Korean Home Economics Association
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• v.32 no.5
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• pp.55-66
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• 1994

The aim of this study is to propose the reasonable method of evaluation on the value of the life-time household work. for homemaker claim her share in the matrimonial property in relation to her life-time household work and to provide the basic data to measuring proper compensation for homemaker and calculating of the donation tax and inheritance tax amount. Tom compare the difference of the method of evaluation on the value of the life-time household work is evaluted by three methods: the model of the life-time household work which is reflected major variables in the FLC frame work marital stage, total marital period. The major findings are as follows: 1) Among the three evaluation me？ The method of Total marital period is evaluatied the lowest value of the life-time household work. 2) The evaluation method of marital stage is more resonable method than the method of total marital period habe a convenience of evaluation but it dos'nt reflected major variables which influence the value of life-time household work. 3) the most resonable method of evaluation on the value of the life-time household work is revealed the model of the life-time household work which is reflected major variables in the FLC frame work the age of first and last offspring marital period.

• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.173-184
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• 2004

A statistical software for nonlinear regression analysis, NLIN2000, is introduced. This software, operated tinder the Window systems, has many user-friendly functions and Provides various statistics. As an upgraded version of the Previous Program operated under the DOS system, NLIN2000 provides easier steps for model specification and fitting process than any other statistical packages. Also it has a database system for model functions which has addition and deletion options. While it can be a useful research tool for statisticians, NLIN2000 can be used practically also by researchers in many other scientific fields, who needs nonlinear regression analysis for their study.

• Geomechanics and Engineering
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• v.21 no.3
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• pp.247-258
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• 2020

The shear strength of unsaturated soils, a research hotspot in geotechnical engineering, has great guiding significance for geotechnical engineering design. Although kinds of calculation models for the shear strength of unsaturated soil have been put forward by predecessors, there is still need for new models to extensively consider the nonlinear variation of shear strength, particularly for the nonlinear effect of the net normal stress on the shear strength of unsaturated soil. Here, the shear strength of unsaturated soils is explored to study the nonlinear effects of net normal stress with the introduction of a general nonlinear Mohr-Coulomb (M-C) strength criterion, and the relationship between the matric suction (or suction stress) and degree of saturation (DOS) constructed by the soil-water characteristics curve (SWCC) of van Genuchten is also applied for unsaturated soil. Then, two calculation models (i.e., an envelope shell model and an effective stress model) are established for the shear strength of unsaturated soils under the nonlinear strength theory. In these two models, the curve of the shear strength of unsaturated soils versus the net normal stress exhibits a tendency to gently. Moreover, the proposed formulas have flexibility and convenience with five parameters (for the effective stress model) or six parameters (for the envelope shell model), which are from the M-C strength parameters of the saturated soil and fitting parameters of SWCC of van Genuchten. Thereafter, by comparison with the classical theory of the shear strength of unsaturated soils from some actual cases, the rationality and accuracy of the present models were verified.

• Wind and Structures
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• v.10 no.3
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• pp.287-300
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• 2007

Wind action is a factor of fundamental importance in the structural design of light or slender constructions. Codes for structural design usually assume that the incident mean wind velocity is parallel to the ground, which constitutes a valid simplification for frequent winds caused by meteorological phenomena such as Extratropical Storms (EPS) or Tropical Storms. Wind effects due to other phenomena, such as thunderstorms, and its combination with EPS winds in so-called squall lines, are simply neglected. In this paper a model that describes the three-dimensional wind velocity field originated from a downburst in a thunderstorm (TS) is proposed. The model is based on a semi empirical representation of an axially-symmetrical flow line pattern that describes a stationary field, modulated by a function that accounts for the evolution of the wind velocity with time. The model allows the generation of a spatially and temporally variable velocity field, which also includes a fluctuating component of the velocity. All parameters employed in the model are related to meteorological variables, which are susceptible of statistical assessment. A background wind is also considered, in order to account for the translational velocity of the thunderstorm, normally due to local wind conditions. When the translation of the TS is caused by an EPS, a squall line is produced, causing the highest wind velocities associated with TS events. The resulting vertical velocity profiles were also studied and compared with existing models, such as the profiles proposed by Vicroy, et al. (1992) and Wood and Kwok (1998). The present model predicts horizontal velocity profiles that depend on the distance to the storm center, effect not considered by previous models, although the various proposals are globally compatible. The model can be applied in any region of interest, once the relevant meteorological variables are known, to simulate the excitation due to TS winds in the design of transmission lines, long-span crossings, cable-stayed bridges, towers or similar structures.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.3
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• pp.315-323
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• 2004

An electrical cascade impactor is a multi-stage impaction device to separate airborne particles into aerodynamic size classes using particle charging and electrical detection techniques. A Faraday cage and an aerosol charger, which are basic components of the electrical cascade impactor, were designed and evaluated in this study. The low-level current response of the Faraday cage was investigated with changing particle size and air flow rate by using sodium chloride (NaCl) particles. The response of the prototype Faraday cage was very similar to that of a commercial aerosol electrometer (TSI model 3068) within ${\pm}$5% for singly-charged particles. The response linearity of the prototype Faraday cage could be extended up to flow rate of 30 L/min. For the performance evaluation of the aerosol charger the monodisperse liquid dioctyl sebacate (DOS) particles, with diameters of 0.1∼0.8$\mu\textrm{m}$, were generated using spraying from an atomizer followed by evaporation-condensation process. Typical performance parameters of the aerosol charger such as P$.$n, wall loss, and elementary charges per particle were evaluated. The performance of the prototype aerosol charger was found to be close to that of the aerosol charger used in an electrical low pressure impactor (ELPI, Dekati).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.25-30
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• 2008

This paper presents on research findings of how Visual C++ program can be used to generate codes capable of performing ramjet engine simulation an arbitrary ramjet model will be considered for which generated output values will be compared with those from a commercial program GASTURB 9 Several governing thermodynamic equations will first be discussed in order that we understand the fundamental idea behind values printed out on the GUI. The program is designed that it generates its station input value. Similar results were realized compared to those produced by gasturb 9.