• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.793-802
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• 2008

The development methods which utilize OSSs have been tried as new alternative to solve limits of the previous software developments such as the quality of software, and time and cost of developments. Especially, small and medium companies are suffering from difficulty in applying large-scale development methodology whenever they develop softwares. Therefore, in the current situation that demand for small-scale development methodology is increasing, the methods of utilizing OSSs can become an efficient way to save costs and reduce a development period. Accordingly, analysis of open-source is no fixed procedure or method to utilize open-source for software developments in the field. In this thesis, to solve such problems, we propose the procedures and methods for identifying and selecting suitable open-source, and effective methods for improvement and integration through least modification on the basis of synthesis of existing researches and experiences in development projects. For selection of OSSs, we did identify correct requirements for the software to be developed, investigate the open-source just matching with such requirements, draw a candidate index, establish assessment criteria, and the consequently present a method to select OSSs. And, we deduced the validity and improvement of each detailed activity from practical application to an actual project and assessment.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.9
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• pp.293-300
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• 2014

TDMA(Time Division Multiple Access) is a channel access scheme for shared medium networks. The shared frequency is divided into multiple time slots, some of which are assigned to a user for communication. Techniques for TDMA can be categorized into two classes: synchronous and asynchronous. Synchronization is not suitable for small scale networks because it is complicated and requires additional equipments. In contrast, in DESYNC, a biologically-inspired algorithm, the synchronization can be easily achieved without a global clock or other infrastructure overhead. However, DESYNC spends a great deal of time to complete synchronization and does not guarantee the maximum time to synch completion. In this paper, we propose a lightweight synchronization scheme, C-DESYNC, which counts the number of participating nodes with GP (Global Packet) signal including the information about the starting time of a period. The proposed algorithm is mush simpler than the existing synchronization TDMA techniques in terms of cost-effective method and guarantees the maximum time to synch completion. Our simulation results show that C-DESYNC guarantees the completion of the synchronization process within only 3 periods regardless of the number of nodes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.122-129
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• 2017

This study presents the results from a technical analysis of a portal system that is compatible with MRV regulations and utilized to examine energy efficiency in international shipping, in relation to the implementation of a mandatory data collection system by the International Maritime Organization. The details of the SEEMP guidelines, including the data collection system and methods for collecting data on fuel use, were reviewed. Strategies for domestic shipping companies toward MRV have been recommended by identifying differences with the EU MRV, and the technical adequacy of the MRV system was assessed. The MRV system enhances cost and work efficiency by managing emissions data from the early stage to the final stage. It is capable of collecting and reporting emissions data while adhering to the reporting procedures of shipping companies. By granting different access privileges to users, the system supports shipping companies in their data collection and reporting, and also supports verifiers in their data verification activities. Moreover, it makes possible the submission of reports in electronic from, thereby enabling shipping companies to adopt an integrated response to international MRV regulations.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.113-122
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• 2009

The domestic construction market started to expand steadily since 1970s. The building market which utilizes a sandwich panel with advantages of economical construction expenses and convenient construction has grown rapidly in recent years. However, the companies which specialize in constructing sandwich panels are relatively small or medium size, compared with other construction companies. As a result, studies on the improvement of productivity have not been conducted sufficiently. In this study, the construction sites of sandwich panel are investigated, and the work processes by each team are analyzed. Additionally, the productivity and the construction cost of each work group are analyzed by constructing a model using the Web-Cyclone. It analyzed sensitivities about change of productivity and work costs following in processing place of the panel which is one of the productivity effect factors, so it assayed the optimized productivity by each work group and work costs. Analysis showed that 30% of productivity has improved compared with the factory processing work group, and analysis of work costs showed that about 15% of work costs was increased. Also sensitivity analysis of opening ratio showed that the work costs optimization will be accomplished when about 20% of opening was processed from the factory.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.78-78
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• 2013

Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of microelectronic devices because of their low resistivity and high work-function. However the material cost of Ru is very expensive and it usually takes long initial nucleation time on SiO2 during chemical deposition. Therefore many researchers have focused on how to enhance the initial growth rate on SiO2 surface. There are two methods to deposit Ru film with atomic layer deposition (ALD); the one is thermal ALD using dilute oxygen gas as a reactant, and the other is plasma enhanced ALD (PEALD) using NH3 plasma as a reactant. Generally, the film roughness of Ru film deposited by PEALD is smoother than that deposited by thermal ALD. However, the plasma is not favorable in the application of high aspect ratio structure. In this study, we used a bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a metal organic precursor for both thermal and plasma enhanced ALDs. In order to reduce initial nucleation time, we use several methods such as Ar plasma pre-treatment for PEALD and usage of sacrificial RuO2 under layer for thermal ALD. In case of PEALD, some of surface hydroxyls were removed from SiO2 substrate during the Ar plasma treatment. And relatively high surface nitrogen concentration after first NH3 plasma exposure step in ALD process was observed with in-situ Auger electron spectroscopy (AES). This means that surface amine filled the hydroxyl removed sites by the NH3 plasma. Surface amine played a role as a reduction site but not a nucleation site. Therefore, the precursor reduction was enhanced but the adhesion property was degraded. In case of thermal ALD, a Ru film was deposited from Ru precursors on the surface of RuO2 and the RuO2 film was reduced from RuO2/SiO2 interface to Ru during the deposition. The reduction process was controlled by oxygen partial pressure in ambient. Under high oxygen partial pressure, RuO2 was deposited on RuO2/SiO2, and under medium oxygen partial pressure, RuO2 was partially reduced and oxygen concentration in RuO2 film was decreased. Under low oxygen partial pressure, finally RuO2 was disappeared and about 3% of oxygen was remained. Usually rough surface was observed with longer initial nucleation time. However, the Ru deposited with reduction of RuO2 exhibits smooth surface and was deposited quickly because the sacrificial RuO2 has no initial nucleation time on SiO2 and played a role as a buffer layer between Ru and SiO2.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.136-142
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• 2015

The Korean Society of Pediatric Infectious Diseases (KSPID) has participated in the task force team consisting of government authorities as well as civil medical experts and facilities to block the spread of Middle East Respiratory Syndrome in 2015. KSPID posted the "Middle East Respiratory Syndrome (MERS) Pop-up" in the homepage of The Korean Pediatric Society and The Korean Society of Pediatric Infectious Diseases. KSPID also released the "Guidelines for testing for MERS in children and adolescents" and the "Instructions for the Operation of National Safe Hospital" for children and adolescents in a timely manner. Such actions were aimed to prevent unnecessary anxieties, studies and isolation of pediatric patients with respiratory symptoms and signs caused by other common microbial etiologies as being suspected for MERS patients. This strategy relieved the doctors and parents from unnecessary fear and prevented the loss of unnecessary health care costs, and has proven to be a well-judged guideline and management protocol as evaluated after the final end of MERS outbreak. KSPID and its members should support the presence of pediatric infectious disease (PID) specialists in every medium size hospitals in Korea by developing the need for consultation fees for PID consultation in the hospital based practice and promoting the potential for cost savings related to prevention of health care associated infections and optimal prescription of antimicrobial agents. KSPID and its members need to approach and develop a communication plan to political decision makers to demonstrate and convince them of the importance of a PID specialist service.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.11
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• pp.915-924
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• 2014

In an aero gas-turbine engine, a surface air-oil heat exchanger (SAOHE) is used to cool the oil system for the gearboxes and electric generators. The SAOHE is installed inside the fan casing of the engine in order to dissipate the heat from the oil system into the bypass duct stream. The purpose of this study was to develop an effective numerical method for designing an SAOHE for an aero gas-turbine engine. A two-dimensional model using a porous medium was developed to evaluate the aero-thermal performance of the fins of the heat exchanger, and a one-dimensional flow and thermal network program was developed to save time and cost in the evaluation of the heat exchanger performance. Using this network program, the pressure drop and heat transfer performance of the heat exchanger were predicted, and the results were compared with two-dimensional computational fluid dynamics results and experiment data for validation.

• Korean Journal of Optics and Photonics
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• v.12 no.2
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• pp.135-142
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• 2001

Recently, plastic optical fiber draws a lot of attention as a new transmission medium for local area network (LAN) and home network applications. As PMMA based GI-POF (Graded Index Plastic Optical Fiber) has very low loss at about 500 nm and 650 nm wavelengths, it is very important to have a compact ultra short optical pulse source at these wavelength windows. In this paper, we have investigated detailed characteristics of gain switched laser system by using a commercially available low cost RF devices and an InGaAlP Fabry Perot semiconductor laser operating at 650 nm wavelength. The shortest optical 'pulse obtained was 33 psec with 1 GHz repetition rate. Depending on the DC bias current and the modulation frequency, the FWHM and the pulse energy of the gain switched pulses show 33.3-82.8 psec and 0.97-9.69 pI respectively. Also, the spectral bandwidths for CW and gain switched operations are 0.44 nm and 1.50 nm. We believe that these results are quite useful for high bit rate optical transmission applications with PMMA based plastic optical fibers in addition to estimate properties of ultra fast optical components and electro-optic devices. vices.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.744-753
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• 2021

This study suggests ways to improve the standard test method and judgment criterion for the "Eco-toxicity Test" based on the rules and regulations provided in 'performance and qualifying test standards for marine pollution prevention materials and chemicals' in the Republic of Korea. Compared with the relevant references of other countries, this study attempted to find the limitations in the existing standards. As for the growth inhibition test of algae using Skeletonema costatum as an indicator, applying comparative analysis to measure specific growth rates, together with statistical analysis, instead of applying current methods, judged by the appearance of colors from the culture medium was suggested. Considering the exponential growth phase of the test species, the test duration was suggested to be reduced to less than four days. For the test with fish as an indicator, resetting the appropriate body size was suggested to, show consistent sensitivity against chenicals applied during testing. Furthermore, it is necessary to consider the criteria needs, which should be established in reasonable and objective ways. For the testing species, marine rotifer, Brachionus plicatilis could be a replacement for Artemia sp., and a bivalve for fish in the test. To improve the performance effectiveness of the "Eco-toxicity test", it is worth considering the designation of accredited testing institutes, by placing it in the same loop. Thus it is also expected to have a reliable management system in place, having the capacity of cost calculation properly and adjusting testing items if required.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.2
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• pp.168-174
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• 2021

According to the World Agricultural Productivity Report, the current annual average growth rate of agriculture is 1.63%, which is lower than 1.73% to support the world's 10 billion people, which is growing by 2050. The demand for food, feed, and bioenergy is not growing enough to continue to meet the demand, and it is predicting a future food shortage. The purpose of this study was to create a regional irrigation control model for the purpose of reducing the production cost of crops, increasing production, and improving quality, and presenting a model that can give advice to farmers who start farming in the region. The irrigation control modeling presented in this study means to represent the change of medium weight·supply liquid·drainage amount due to changes in the root zone environment according to the passage of time and climate in a graph model. For water control modeling, we collected data on the change in the amount of the root zone environment and the weight of the badge·supply amount·drainage amount from March to June in Nonsan, Buyeo, and Yesan regions in Chungnam Province through the measuring device of the Ministry of Environment in the root region. We set up the parameters for derivation and derived an irrigation control model that can confirm the change in weight·supply liquid·drainage amount over time through the parameters.