• Journal of Software Engineering Society
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• v.29 no.2
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• pp.1-6
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• 2020

Software product line development is a development paradigm that efficiently develops a product family by avoiding redundant development based on separation of the common part and the variable part of the product family. In software product line development, the source code that is used to produce a product family is called a product line code base, and when the product line code base is changed and the products of the product family are affected by the change, the activity of testing the affected products is called a product line regression testing. For product line regression testing, instead of conducting regression testing individually on each product of the product family, a more efficient regression testing would be possible if unnecessary testing that are irrelevant to the change can be avoided. This paper introduces SRTS, which is an automated method to efficiently perform software product line regression testing. SRTS divides the product line code base and test cases based on commonality and variability. Then SRTS identifies and selects the test cases affected by the change. Finally, it reduces unnecessary testing by rerunning only the selected test cases.

• The Journal of the Acoustical Society of Korea
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• v.18 no.7
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• pp.92-100
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• 1999

In the microcell mobile communication, we propose algorithms processing operational disposition to exactly analysis propagation environments from the base station to mobile stations. Algorithms are developed by the triangle analysis method can operate variable propagation paths and reflect numbers. For simulation, we suppose that mobile stations are located in the shadow region of the line of sight and the area of the non-line of sight sloping against the line of sight area at variable angles. By analyzing the results of simulation using proposed algorithms, we can be applied to the optimal position selection of the base station in the microcell mobile communication.

• Journal of the Semiconductor & Display Technology
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• v.4 no.3 s.12
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• pp.23-27
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• 2005

The effects of the base vacuum level on a plasma display panel (PDP) produced by the vacuum in-line sealing technology were investigated. The main equipment of the vacuum in-line sealing process consists of the sealing chamber, pumping systems for evacuating, mass flow controller for introducing the plasma gases, and other measuring systems. During the sealing process, the impurity gases were fully evacuated and the panel was prevented from the adsorption of impurity gases. As a result, the brightness increased as the impurity gas density decreased, so we found that the vacuum in-line sealing process was more efficient technology an the conventional sealing process.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.3
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• pp.89-93
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• 2007

In this study, we consider an assembly line operated under a base-stock policy. A product consists of two parts, and a finished product transfers to a warehouse in which demands are satisfied. Assume that demands arrive according to a Poisson process and processing times at each production line are exponentially distributed. Whenever a demand arrives, it is satisfied immediately from an inventory in the warehouse if available; otherwise, it is backlogged and satisfied later by the next product exiting from production lines. In either case, an arriving demand automatically triggers the production of a part at both production lines. These two parts will be assembled into a product that eventually transfers to the warehouse. We obtain a closed form formula of approximation for delay time or lead time distribution of a demand when a base- stock level is s. Moreover, it can be applied to the optimal base-stock level which minimizes the total inventory cost. Numerical examples are presented to show our optimal base-stock level's quality.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.545-551
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• 2011

In this paper, we described a measurement method of an EIRP(Effective Isotropic Radiated Power) of a WCDMA base station using a pilot channel in line-of-sight environments. Especially we measured it in real base station environments in order to apply this method to domestic base station inspection test. Estimated EIRP results from measured value is -2 dB lower than theoretical values, which is calculated by the data of transmit antenna. The deviation of -2 dB is verified as a polarization mismatch between the base station antenna and a receiver antenna, and it can be calibrated. Therefore, we verified that our measurement method could be an effective tool to measure an EIRP in WCDMA base station inspection test.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.57-63
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• 2006

We have examined the electrical and optical characteristics of the plasma display panel(PDP) produced by vacuum in-line sealing technology. We found that the luminous efficiency was decreased as the base vacuum level was increased. For the base vacuum level of $1\times10^{-3}$ Torr, the firing voltage was 235V at the discharge gas pressure of 400 Torr and the luminous efficiency was 0.8 lm/W at 180V sustaining pulse. However, for the base vacuum level of $1\times10^{-6}$ Torr, the firing voltage was reduced to 215V and the luminous efficiency was improved to 2.5lm/w. Finally, we demonstrated successfully the operation of tip-less PDP fabricated using vacuum in-line sealing method.

• Journal of Welding and Joining
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• v.14 no.5
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• pp.122-133
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• 1996

In order to evaluate the cryogenic fracture characteristics of structural steels for superconducting magnets of fusion reactor, small punch (SP) testing was performed on austenitic stainless steel (JN1 base metal) and its TIG weldments at 293K, 77K and 4K. The mechanical properties with respect to the extracted location of the weld metal, on the effects of welding heat cycle about base metal near fusion line in TIG weldments were investigated. The mechanical property of the weld metal in TIG weldments depends on distance from welding root, root region of weldments having the lowest mechanical property. The base metal near fusion line showed degradation of mechanical property caused by cyclic heating during the TIG welding. Based on the test results, HAZ was found to be up to 5mm from the fusion line. It is shown that SP testing is a useful tool to evaluate the mechanical properties with respect to the microstructures changes such as HAZ as well as weld metal in TIG weldments at cryogenic temperature.

• Membrane and Water Treatment
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• v.8 no.2
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• pp.185-199
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• 2017

Low-pressure membrane filtration is increasingly used for tertiary treatment of wastewater effluent organic matter (EfOM), mainly comprising organic base/neutral compounds. In-line coagulation with underdosing, charge neutralization, and sweep floc conditions prior to ultrafiltration (UF) was studied to determine removals of the EfOM components and consequent reduction of fouling using polyethersulfone membranes. Coagulation and UF substantially reduced fouling for all coagulation conditions while removing from 7 to 38% of EfOM organic acids. From 7 to 16% of EfOM organic base/neutrals were removed at neutral pH but there was no significant removal for slightly acid coagulation conditions even though fouling was substantially reduced. Sweep floc produced the lowest resistance to filtration but may be inappropriate for in-line use due to the large added volume of solids. Charge-neutralization resulted in poor recovery of the initial flux with hydraulic cleaning. Under-dosing paralleled sweep floc in reducing hydraulic resistance to filtration (for sub-critical flux) and the initial flux was also easily recovered with hydraulic cleaning. Hydrophobic and hydrophilic base/neutrals were identified on the fouled membranes but as previously reported the extent of fouling was not correlated with accumulation of organic base/neutrals.

• Strategy21
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• s.44
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• pp.291-322
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• 2018

This research aims to cast light upon security characteristics of the Peace Line, which have been underestimated. To understand maritime order and maritime security policy of the Republic of Korea between 1950 and 1970, it is necessary to analyze the Peace Line as line of defence and to investigate its character This research begins with analyzation of historical facts and investigation on security characteristics of the Peace Line. It goes further to examination of legal justification of the Peace Line, which was one of international legal issues of the period, principally regarding its security characteristics. As results of the study, it could be said that the security characteristics of the Peace Line was the line of defensive waters, which set its goal mainly to prevent infiltration of communist spies. The Peace Line had practical effect as it functioned as a base line of the ROK Navy to take anti-spy operation. At the early phase of the Korea-Japan Negotiation, the Korea delegation interpreted significance of the Peace Line passively. After abrogation of Clark Line, the delegation, however, became positive to maintain the Peace Line and its security characteristics. Security characteristics of the Peace Line was recognized again, as it became the base line of special maritime zone which was made in 1972. Through analysis on international law, it is concluded that the Peace Line was fair as a part of the right of self-defense against indirect aggression. North Korea attempted indirect aggression mainly from sea way, and these might undermine peace and cause urgent and unjust damage on the ROK. Thus the ROK's action of anti-spy operation through the Peace Line can be justifiable as considering the right of self-defence. Also the Peace Line accorded with principles of necessity, immediacy and proportionality. As it was argued on the above, the Peace Line as line of defence was one of the most significant factor in the ROK's maritime security history from the Hot war against communist forces to Cold war period after Korean War and must not be underestimated.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.219-223
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• 2001

The on-line cure monitoring during the cure process of composite materials is important for better quality and productivity. The dielectric sensor for cure monitoring consists of base film and electrodes. Because the characteristic of dielectric sensor for the on-line cure monitoring is dependent on the base material, width and number of electrode, etc, the dielectric sensor should be standardized. And the selection of base film material of sensor is very important. In order to prevent the measuring errors generated from the increase of environmental temperature, the base film material should have stable dielectric constant with respect to environmental temperature. In this study, the newly developed dielectric sensor for cure monitoring was designed and the dissipation factor which is function of degree of cure was measured using the sensor. The relationship between the dissipation factor and degree of cure with respect to environmental temperature was investigated.