• Proceedings of the Korean Society for Bioinformatics Conference
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• 2000.11a
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• pp.32-34
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• 2000

Computational chemistry is a discipline using computational methods for the calculation of molecular structure, properties, and reaction or for the simulation of molecular behavior. Relating and turning the complexity of data from genomics, high-throughput screening, combinatorial chemical synthesis, gene-expression investigations, pharmacogenomics, and proteomics into useful information and knowledge is the primary goal of bioinformatics. In particular, the structure-based molecular design is one of essential fields in bioinformatics and it can be called as structural bioinformatics. Therefore, the conformational analysis for proteins and peptides using the techniques of computational chemistry is expected to play a role in structural bioinformatics. There are two major computational methods for conformational analysis of proteins and peptides; one is the molecular orbital (MO) method and the other is the force field (or empirical potential function) method. The MO method can be classified into ab initio and semiempirical methods, which have been applied to relatively small and large molecules, respectively. However, the improvement in computer hardwares and softwares enables us to use the ab initio MO method for relatively larger biomolecules with up to v100 atoms or ∼800 basis functions. In order to show how computational chemistry can be used in structural bioinformatics, 1 will present on (1) cis-trans isomerization of proline dipeptide and its derivatives, (2) positional preference of proline in ${\alpha}$-helices, and (3) conformations and activities of Arg-Gly-Asp-containing tetrapeptides.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.659-664
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• 2000

In this paper, We have discussed on the modeling of machined outer geometry which was established for the case of round shape machining, also the effects of externally machined profile are analyzed and its modeling realiability was verified by the experiments of roundness testing, especially in lathe operation. In this study, we established harmonic geometric model with the parameter harmonic function. In general, we can calculate the theoretical roundness profile with arbitrary multilobe parameter. But in real experiments, only 2-5 lobe profile was frequently measured. the most frequently ones are 3 and 5 lobe profile in experiments. With this results, we can predict that these results may be applies to round shape machining such as turning, drilling, boring, ball screw and cylindrical grinding operation in bearing and shaft making operation with the same method. In this study, simulation and experimental work were performed to show the profile behaviors. we can apply these new modeling method in real process for the prediction of part profile behaviors machined such as in round shape machining operation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.191-194
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• 2003

Through using aspheric lens can result in advantages such as an improved optical transfer function, a reduced distortion path or the realization of special image field curvatures. Using the diamond turning method for generating aspherics, the company claim to be able to generate surfaces with a form error of less than $0.33\;{\mu}\;m$ and a surface roughness of less than $0.025\;{\mu}\;m$. In this paper, we are manufacturing thermal image aspheric lens. Thermal image system is electro-optical imaging device which can make visible the difference of infrared energy naturally emitted by objected. In the result of aspherical surface, the form accuracy of about $0.24\;{\mu}\;m$ P-V was obtained and the surface roughness Ra $0.004\;{\mu}\;m$. Also, a brief review of Ultra-precision system Korea photonics technology institute(KOPTI) is present in this paper.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.34-40
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• 1998

The burr produced on piece part edges in machining operations must be removed for most parts to function effectively. Although considerable cost have been expended in improving deburring methods, little energy has been applied toward minimizing burrs. This study has been carried out to prevent the burrs produced on pure aluminium under various working condition and specimen shape in turning operations. The computer image processing system was used for measurement of size of burr, such as burr length, burr depth and burr area. The size of burr showed a decreasing tendency with the increase of rake angle and side cutting angle but it increased rapidly with the increase of depth of cut and the cutting speed has no effect on size of burrs. The size of burr rapidly decreased with the increase of edge angle and burrs are not occurred if edge angle is over 80$^{\circ}$.

• Journal of Korean Port Research
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• v.13 no.2
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• pp.215-232
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• 1999

Privatisation has emerged within the past few decades as one of the most significant challenges to public ports and their governments throughout the world. More than forty countries have committed to some form of port privatisation thus far and they will quite likely be joined by dozens more by the turn of the century. A decision to privatise ports can be driven by a variety of forces. The most obvious is to relieve a financially strapped government by turning to the private sector for an infusion of capital required to modernise and sustain port operations, or to bolster the national treasury. Inefficient and costly port operations can seriously impair the competitiveness of a nation’s export industries and artificially raise the cost and thus constrain the availability of imported goods. Privatisation in certain circumstances therefore holds the promise of stimulating economic growth particularly for those whose livelihood depends directly upon port activity and trade. The main objective of this paper is first of all, to introduce a variety of methods of port privatisation after reviewing the reason why port facilities should be privatised. This paper also aims to make some proposals with which a port privatisation process in Korea can be improved after summarising the present Terminal Operating Company(TOC) system propelled by Ministry of Maritime Affairs and Fisheries.

• ETRI Journal
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• v.28 no.3
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• pp.282-290
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• 2006

In vertically overlaid cellular systems, a temporary traffic concentration can occur in a hot-spot area, and this adversely affects overall system capacity. In this paper, we develop an adaptive hot-spot operating scheme (AHOS) to mitigate the negative effects from the nonuniform distribution of user location and the variation in the mixture of QoS requirements in orthogonal frequency division multiple access downlink systems. Here, the base station in a macrocell can control the operation of picocells within the cell, and turns them on or off according to the system overload estimation function. In order to determine whether the set of picocells is turned on or off, we define an AHOS gain index that describes the number of subcarriers saved to the macrocell by turning a specific picocell on. For initiating the picocell OFF procedure, we utilize the changes in traffic concentration and co-channel interference to the neighboring cells. According to computer simulation, the AHOS has been proved to have maximize system throughput while maintaining a very low QoS outage probability under various system scenarios in both a single-cell and multi-cell environments.

• Journal of Mechanical Science and Technology
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• v.19 no.12
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• pp.2205-2212
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• 2005

In this paper, the cutting torque of a CNC machine tool during machining is monitored through the internet. To estimate the cutting torque precisely, the spindle driving system is divided into two parts: electrical induction motor part and mechanical part. A magnetized current is calculated from the measured three-phase stator currents and used for the total torque estimation generated by a spindle motor. Slip angular velocity is calculated from the magnetized current directly, which gets rid of the necessity of a spindle speed sensor. Since the frictional torque changes according to the cutting torque and the spindle rotational speed, an experiment is adopted to obtain the frictional torque as a function of the cutting torque and the spindle rotation speed. Then the cutting torque can be calculated by solving a $2^{nd}$ order difference equation at a given cutting condition. A graphical programming method is used to implement the torque monitoring system developed in this study to the computer and at the same time monitor the torque of the spindle motor in real time through the internet. The cutting torque of the CNC lathe is estimated well within an about $3\%$ error range in average in various cutting conditions.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.3
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• pp.203-212
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• 2010

In this paper, we present an analytical model for the first eigen energy level ($E_0$) of the carriers in the inversion layer in present generation MOSFETs, having ultrathin gate oxides and high substrate doping concentrations. Commonly used approaches to evaluate $E_0$ make either or both of the following two assumptions: one is that the barrier height at the oxide-semiconductor interface is infinite (with the consequence that the wave function at this interface is forced to zero), while the other is the triangular potential well approximation within the semiconductor (resulting in a constant electric field throughout the semiconductor, equal to the surface electric field). Obviously, both these assumptions are wrong, however, in order to correctly account for these two effects, one needs to solve Schrodinger and Poisson equations simultaneously, with the approach turning numerical and computationally intensive. In this work, we have derived a closed-form analytical expression for $E_0$, with due considerations for both the assumptions mentioned above. In order to account for the finite barrier height at the oxide-semiconductor interface, we have used the asymptotic approximations of the Airy function integrals to find the wave functions at the oxide and the semiconductor. Then, by applying the boundary condition at the oxide-semiconductor interface, we developed the model for $E_0$. With regard to the second assumption, we proposed the inclusion of a fitting parameter in the wellknown effective electric field model. The results matched very well with those obtained from Li's model. Another unique contribution of this work is to explicitly account for the finite oxide-semiconductor barrier height, which none of the reported works considered.

• Women's Health Nursing
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• v.3 no.1
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• pp.82-92
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• 1997

The purpose of this study was attempted to understand the substance and meaning of menopause experienced by women through informal interviews with oral consent. The informants were 6 perimenopausal women of 50-55 years old who are executing menopause. Colaizz's analytical method, a type of phenomenological analysis, was used to analyze data recorded by audiotape. One professor and a master's degree student who understand phenomenology, and the one who has a master of arts examined the validity between the meanings composed of the clusters of themes. Findings were turned out to be valid through validation process as the last step. The meaning of menopause implied both 'concept about menopause' and 'menopause as a time of change'. Menopause was mostly considered as cessation of menstruation as a physiological, natural, and normal process by aging. However, some people regarded menopause as a loss of youth and womanhood and lessening of every function of the body. Menopause as the time of changes means 'the period of' 'hormonal changes' such as change of menstruation, hot flushes, perspiration, and palpitation ; 'body function changes' of visual acuity, physical strength, sleeping, digestion, thoughts, bone and joints, skin sensibility, sexual pattern and intelligence ; 'emotional changes' such as anxiety, loneliness, gloominess, and nervousness. Menopause is a turning point on the women's life cycle accompanying various kind of changes and health problems. Therefore it is inevitable to develop strategy helping menopausal women pass through the critical successfully by adapting and coping with their critical period toward the healthy and better quality of life individually rather than putting them all into the standardized hormonal replacement protocol.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.89-97
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• 2006

With the increased demand on housing quality and effective urban redevelopment, a new paradigm in reconstruction project is in need. Especially, the Urban and Residential Environment Improvement Law which initiated on July 1, 2003 has become a significant turning point. This code is expected to function as a consistent and systematic measure. This study will examine the code's major concepts and methods to progress reconstruction projects effectively. The application of construction management is examined carefully since the new code requires renewal project consulting firms to function as a professional complement rather than simply perform administration work, as in the past. Also, construction managing methods that can be related to renewal project consulting are examined and speculated. Lastly, methods to improve efficiency in reconstruction projects are introduced through case study and analysis on applicability and expected results.