• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.865-876
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• 2002

Successful project planning relies on a good estimation of the effort required to complete a project, together with the schedule options that may be available. Existing software effort estimation models are present only the total effort and instantaneous effort function for the software life-cycle. Also, Putnam presents constant effort rate in each phase. However, the size of total effort varies according to the software projects under the influence of its size, complexity and operational environment. As a result, the allocated effort in each phase also differs from one project to another. This paper suggests models for effort allocation in planning, specifying, building, testing and implementing phases followed by the project size and development types. These models are derived from 155 different projects. Therefore, these models can be considered as a practical guideline in management of project schedule and effort allocation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.566-572
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• 2016

Software Reliability implemented in software development is one of the most important issues. In finite failure NHPP software reliability models for software failure analysis, the hazard function that means a failure rate may have constant independently for failure time, non-increasing or non-decreasing pattern. In this study, software development cost analysis considering the variable shape parameter of Erlang distribution as the failure life distribution in the software product testing process was studied. The software failure model was applied finite failure Non-Homogeneous Poisson Procedure and the parameters approximation using maximum likelihood estimation was accompanied. Thus, this paper was presented comparative analysis by applying a software failure time data to the software, considering the shape parameter of Erlang distribution for development cost model analysis. When compared to the cost curve in accordance with the shape parameter, the model of smaller shape can be seen that the optimal software release time delay and more cost. Through this study, it is thought that it can serve as a preliminary information which can basically help the software developers to search for development cost according to software shape parameters.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.115-121
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• 2013

It is greatly expected that the technologies of durability enhancement and evaluation for the core structures of plant facilities, marine plant and bridge constructures will be greatly expanded in the plant industry fields. In this study, the actively ongoing applied cases were tried to be analyzed in the present domestic industry fields through the Ultrasonic Nanocrystalline Surface Modification (UNSM) and Ultrasonic Fatigue Test (UFT) technologies using ultrasonic elastic vibrational energy, and the new application technology to improve the durability of plant industry field, especially plant facilities, marine plant and core weld components of bridge constructures will be presented.

• Archives of design research
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• v.16 no.2
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• pp.49-56
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• 2003

In order to design a product for old people, it is important to identify usability problems through usability test and solve such problems in design process. So, we performed a study on design evaluation and improvement focusing on washing machine, that is one of the most useful electric home appliances in old people's daily life. Also, we studied the method that the goniometer can be used in usability evaluation for a specific part of product and the result can be used in product design. And, methods for the decision of design concept and direction, the development of design alternatives, design evaluation, model making, and comparison test through human factors theory and experiment were studied. The result can be used as an important data in the development of washing machine for old people and the proposed methodology can be used in other products for old people as well as washing machine.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.95-99
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• 2017

The lifetime of a battery that supplies all the power required by a satellite in the eclipse is directly related to the lifetime of the satellite. Because the lifetime of the battery is influenced by the charging method of the battery, the power control unit that controls the charging of the battery should be designed in consideration of battery life. The battery charging is performed by controlling the charge current in the power control unit generated from the solar cell in the daytime. In order to prevent overcharge of the battery and for considering frequency of eclipse in each season, parameters related battery charging should be designed differently according to the season and to prevent over-current charging and over-voltage charging during charging, charge current is controlled by monitoring battery charge / discharge status, charge current amount, battery voltage, battery capacity, battery temperature and battery cell voltage. In satellite, tapering method is used to control charge current by reflecting each condition. In this paper, design battery charging algorithm of satellite power control unit using tapering charging method. convert the designed algorithm into a code that can be uploaded to satellites and verify the operation through testing in the established satellite environment.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.666-673
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• 2020

The purpose of this study was to investigate the relationship between dental decision factors and dental service satisfaction of the high school students. The study participants consisted of 300 high school students in some regions. A total of 288 were used for the final analysis, except 12 with insufficient responses. The data was analyzed by using SPSS 18.0 program. According to general characteristics, if there was no scaling experience, orthodontic treatment, high satisfaction with school life, the higher the subjective oral health status, the higher the satisfaction of the dental hospital. Hospital decision factors according to the general characteristics of the subjects most frequently answered that employee service satisfaction was important. As a result of testing the correlation between hospital decision factors and medical service satisfaction, there was a significant positive correlation between medical service satisfaction, such as facility, recommendation of others, use procedures, service adequacy, employee service satisfaction. As a factor influencing dental hospital satisfaction, subjective oral health was shown as a good criterion, and usage procedures and staff service satisfaction showed positive relevance. Continuous trust builds up is important to improve patient satisfaction.

• Asian Oncology Nursing
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• v.10 no.1
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• pp.59-67
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• 2010

Purpose: The purpose of this study was the development and validation of knowledge scale for patients with breast cancer (KS-Br) in Korea. Methods: The process included the construction of a conceptual framework, generation of preliminary items, and the test of validity and reliability of the scale. Thirty-seven items were developed through an evaluation process by 10 experts and 24 items were finally confirmed through item analysis. Psychometric testing was performed with a convenient sample of 303 women with breast cancer. The data was analyzed using independent t-test, Pearson's correlation, and calculation of KR-20. Results: Participants averaged 70.8% correct on the test. The KS-Br has 24 items consisting of 5 categories: incidence of breast cancer, diagnosis and treatment, symptom management, sexuality, and maintenance of daily life. Validity was supported by the use of content validity, known-group technique, and criterion-related validity. Women who had undergone education intervention scored significantly higher than women who had not (p<.001). KS-Br scores were significantly correlated with those of Mishel's Illness Uncertainty Scale (r=-.214, p<.001). Internal consistency of the KS-Br was appropriate (KR20=.805). Conclusion: This study reveals that the KS-Br is reliable and valid scale to measure the knowledge of breast cancer. Therefore, this scale can be effectively utilized to assess the knowledge of patients with breast cancer regarding their disease.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1413-1425
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• 2018

Shiga toxins (Stxs) are the main virulence factors expressed by the pathogenic Stx-producing bacteria, namely, Shigella dysenteriae serotype 1 and certain Escherichia coli strains. These bacteria cause widespread outbreaks of bloody diarrhea (hemorrhagic colitis) that in severe cases can progress to life-threatening systemic complications, including hemolytic uremic syndrome (HUS) characterized by the acute onset of microangiopathic hemolytic anemia and kidney dysfunction. Shiga toxicosis has a distinct pathogenesis and animal models of Stx-associated HUS have allowed us to investigate this. Since these models will also be useful for developing effective countermeasures to Stx-associated HUS, it is important to have clinically relevant animal models of this disease. Multiple studies over the last few decades have shown that mice injected with purified Stxs develop some of the pathophysiological features seen in HUS patients infected with the Stx-producing bacteria. These features are also efficiently recapitulated in a non-human primate model (baboons). In addition, rats, calves, chicks, piglets, and rabbits have been used as models to study symptoms of HUS that are characteristic of each animal. These models have been very useful for testing hypotheses about how Stx induces HUS and its neurological sequelae. In this review, we describe in detail the current knowledge about the most well-studied in vivo models of Stx-induced HUS; namely, those in mice, piglets, non-human primates, and rabbits. The aim of this review is to show how each human clinical outcome-mimicking animal model can serve as an experimental tool to promote our understanding of Stx-induced pathogenesis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5669-5675
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• 2012

To reduce the cost and the time of transport in Eurasian railroad networks such as TKR(Trans-Korea Railway), TCR(Trans-China Railway) and TSR(Trans-Siberia Railway) owing to the problem of different track gauges (narrow/standard/broad gauge), it is important to develop the gauge-adjustable wheelset(GAW) system to adapt easily to these gauges. The Korean GAW system is developing and will be adapting to the brand new freight trains' to improve the conventional overseas GAW system. In this study, structural and durability analyses are performed from the viewpoint of the safe-life design. The core parts of the system might be safe in range of $1{\times}10^7$ cycles from the result of durability analysis. Moreover, to examine the safety of the system while running on a track, rig fatigue test was performed according to UIC code. The safety of the Korean GAW system is demonstrated through testing that all safety-relevant conditions are satisfied.

• Journal of Microbiology and Biotechnology
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• v.21 no.8
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• pp.777-790
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• 2011

To elucidate the biodiversity of plant growth-promoting rhizobacteria (PGPR) in Korea, 7,638 bacteria isolated from the rhizosphere of plant species growing in many different regions were screened. A large number of PGPR were identified by testing the ability of each isolate to promote the growth of cucumber seedlings. After redundant rhizobacteria were removed via amplified rDNA restriction analysis, 90 strains were finally selected as PGPR. On the basis of 16S ribosomal RNA sequences, 68 Gram-positive (76%) and 22 Gram-negative (24%) isolates were assigned to 21 genera and 47 species. Of these genera, Bacillus (32 species) made up the largest complement, followed by Paenibacillus (19) and Pseudomonas (11). Phylogenetic analysis showed that most of the Grampositive PGPR fell into two categories: low- and high- G+C (Actinobacteria) strains. The Gram-negative PGPR were distributed in three categories: ${\alpha}$-proteobacteria, ${\beta}$- proteobacteria, and ${\gamma}$-proteobacteria. To our knowledge, this is the largest screening study designed to isolate diverse PGPR. The enlarged understanding of PGPR genetic diversity provided herein will expand the knowledge base regarding beneficial plant-microbe interactions. The outcome of this research may have a practical effect on crop production methodologies.