• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.46-51
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• 2006

As one of the $CO_2$ reduction strategies, a biological method was proposed to convert $CO_2$ to useful biomass with antioxidant carotenoids by photosynthetic microorganisms. One of the photoautotrophs, Haematococcus pluvialis is a freshwater green microalga and accumulates the secondary carotenoid astaxanthin during induction of green vegetative cells to red cyst cells. In this study, $CO_2$ fixation and astaxanthin production using H. pluvialis was conducted by photoautotrophic culture in the $CO_2$ supplemented photo-incubator. Maximum growth rate of H. pluvialis was obtained at a 5％ $CO_2$ environment on basic N and P conditions of NIES-C medium. The photoautotrophic induction consisted of 5％ $CO_2$ supply and high light illumination promoted astaxanthin synthesis in H. pluvialis, yielding an astaxanthin productivity of $9.6mg/L{\cdot}day$ and a $CO_2$ conversion rate of $27.8mg/L{\cdot}day$ to astaxanthin. From the results the sequential photoautotrophic culture and induction process using H. pluvialis is expecting an alternative $CO_2$ reduction technology with a function of valuable biosubstance production.

• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.133-140
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• 2009

This paper presents the experimental study to analyze the pressure and production behavior using depressurization and thermal methods in order to evaluate the hydrate productivity in the 2-D multi-well, plate-type apparatus which has 80 md permeability and 30% hydrate saturation. Injecting methane gas through multi-well allowed to set up the highly saturated hydrate system and combining two different sorts of sands made possible to build up the low permeability system. In this system, both depressurization and electric stimulation methods were applied. When operating pressure was low, according to the depressurization experiments results, the gas recovery was high, however strong pulses which appeared at initial stage of production would damage the operation system. Moreover, cases that hydrate reformed have occurred by endothermic reaction. We have conducted experiments four and six times for the depressurization magnitudes of 140 psi and 320 psi, respectively, to analyze production behavior for the method more in detail. For the cases that the depressurization magnitude was set as 140 psi, the unstable period appears in the results, but stabilized soon. In the experiment results for 320 psi the discontinuous and intermittent behavior has been observed. Thermal stimulation experiments was conducted with depressurizing 80 psi which is the case that shows stable behavior and low recovery. In the results, the gas recovery was high and the energy efficiency was low for long stimulating time. The energy efficiency and gas recovery increased for the soaking time of 1 minute after 2 minute-preheating. In the cases of which the soaking time exceeds 1 minute, energy loss by long soaking time caused low gas recovery and poor energy efficiency.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.209-223
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• 2020

Executions of SCM in a chemical company of which divisions produce petrochemicals, compounds, batteries, IT material and medicine directly affect their own profit. Execution level of SCM or optimization is very important. This work presents activities of SCM and optimization of inefficient issues in several industrial divisions using mathematical optimization method. The meaning is not only academic research but also making a useful tool which active partner deals with in his work. It is explained how to do beforehand and afterward optimization problem. The benefits are mentioned in the sections. The first of examples would be cover supply plan optimization, optimal profit business plan, and scheduling of a stretching process of polarizer based on minimizing raw material loss in polarizer production. The second example would be cover the optimization of production/packaging plans to maximize productivity of Poly Olefin processes, and the third example is minimization of transition loss in the production of battery electrodes. The fourth example would be cover scheduling of vessel approaching to berth. Because transportation of large portion of raw material and products of petrochemical industry is dealt with vessel, scheduling of vessel approaching to berth is important at the shore of large difference of tide. The final example would be scheduling problem to minimization of change over time of ABS semi products.

• The KIPS Transactions:PartD
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• v.13D no.2 s.105
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• pp.271-278
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• 2006

This paper presents industry feedback and a case of improvement trial on enabling reuse driven software development which is one of several activities to improve software quality and productivity in a company which develops software that are embedded into consumer electronic products. Several case studies will be introduced that are related to software reuse strategies and practices to show how to establish environment for reuse basis in a company, how to apply it to development team and project and how to improve that through trials and errors. To enable reuse-oriented software development in a huge company, integrated and focused approach is needed among technical, management and environmental point of view. We tried to solve that problem in technical field with reuse method, in management filed with reuse metric and in environment field with reuse repository. The characteristics of our software development environment could be summarized as below. The first, embedded software which would not independent to hardware devices and the second, it is very huge company which develops extremely various products by many different organization with different domain characteristics and the third, development lead time is extremely short and many variation models are stems from basic models. We expect that our study would give contribution to industry struggling to solve similar problem for presenting our experience and could be a reference model for enabling software reuse in a real world practically.

• The KIPS Transactions:PartD
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• v.13D no.4 s.107
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• pp.565-572
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• 2006

Product Line Engineering (PLE) is an effective reuse methodology where common features among members are captured into core assets and applications are developed by reusing the core assets, reducing development cost while increasing productivity. To maximize benefits in developing systems, business case analysis for PLE is essential. If the scope for core assets is excessively broad, it will result in high cost of asset development while lowering reusability. On the other hand, if the scope is too narrow, it will result in a limited applicability which only support a small number of members in the domain. In this paper, we propose a process for business case analysis for PLE and for deciding economical analysis of core asset scope. Then, we define guidelines for each activity of the process. Since variability often occurs in PLE, we significantly treat the variability of features among members in detailed level. By applying our framework for business case analysis, one can develop core assets of which scope provide the most economical value with applying PLE.

• The KIPS Transactions:PartD
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• v.12D no.7 s.103
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• pp.947-956
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• 2005

Software(S/W) reengineering is one of the effective technologies to produce a business worth and en and the S/W ROI continuously. In spite of, S/W reengineering has been recognized a cost-consumptive works with inefficient productivity. In fact we have used to transform to confusion system with destructive system architecture by extending and updating legacy system in a temporary expedients. Moreover it is impossible to provide the time-market products for coping with rapid changeable system environment and meeting to complicated customer's requirements. Therefore, we need a systematic reengineering methodology to fulfill the changeable environment, as appearance of new IT techniques, various alteration of business information model, and increment of business logic. Legacy systems can be utilized as the core property in business organization through reengineering methodology. In this paper, we target to establish the reengineering process, proposed MaRMI-RE consisting of initial Planning phase, reverse engineering and component transformation phase. To describe the MaRMI-RE, we presented the concrete tasks and techniques and artifacts per individual phase in process, and the case study is showed briefly.

• Resources Recycling
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• v.14 no.4 s.66
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• pp.47-52
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• 2005

Carbonate species in aqueous solution play an important role in the determination of chemical properties of water in relation with alkalinity, buffer capacity, biological productivity, and so on. These compounds also have reactive characteristics such as interphasal reactions between solid, liquid, and gas phases. In the absence of solid materials, the total amount and relative abundance of each carbonate species are directly influenced by the partial pressure of $CO_2$ gas in the atmosphere, which in turn significantly affects the properties of aquatic system. In the water/wastewater treatment process along with the wastes treatment and recycling process which occurring in aquatic environment, it is essential to figure out its characteristics for their optimization and one of its most influential features upon these processes is determined by carbonate species. To understand the fundamental aspect of the relationship between the partial pressure of $CO_2$ gas and chemical features of water, especially pH, the working partial pressure of pure $CO_2$ gas that produced by contacting the dry ice with water has been estimated based on equilibrium calculation. The equilibrium constants for the dissociation ot carbonic acid were determined using van't Hoff equation and the distribution diagram of carbonate species according to the pH has been constructed to substantiate the results of equilibrium calculation. The estimated working partial pressure of pure $CO_2$ gas was found to be a function of the concentration of carbonates in solution, which suggesting that Prior evaluation of the working partial pressure of gas is essential for a better understanding of aquatic interactions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.367-371
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• 2019

The molding for hollow products used widely in industry is rotational molding by heating and cooling. Uniform cooling is required to improve the quality of the product, and rapid cooling is required to improve the productivity. In this paper, the cooling condition is largely classified into the case of no forced cooling by the fan and forced cooling by the fan. In addition, when forced cooling by the fan is not performed, the condition for stopping the molding machine horizontally and the condition for stopping the molding machine vertically were classified. To confirm the forced cooling by the fan, the conditions were set such that only the molding machine rotates while the fan is not running and the upper and lower fans operate when only the lower fan is operated. The surface temperature of the rotary molding machine was analyzed by the STAR-CCM+ program for the case of air-cooling. The temperature distribution of the rotary molding machine was analyzed for five conditions and the temperature distribution for cooling was compared under each condition. Among the five cases, Case 4 was lowest at approximately 35 ℃ after 900sec.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.384-391
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• 2020

An annual average of more than 100 casualties occur on construction sites designated by the occupational safety and health law despite the safety assessment regulations from Korea Occupational Safety & Health Agency. Even if those sites involve more harmful or hazardous work than other sites, the result creates doubt regarding the effectiveness of the safety assessment regulations. The safety of construction sites is difficult to maintain continuously and instantly because ofthe variability in the construction industry despite inspecting workers, equipment, and facilities by managers. Many discussions on how to utilize BIM have been made to improve the productivity of construction projects, and BIM-based modeling and simulation would bring many benefits to safety. This study examined the hindrance factors of field utilization of the safety assessment regulations through a research literature survey, disaster situation analysis and questionnaire, and suggests the necessity of the application of BIM that enhances the effectiveness of safety assessment regulations by identifying the relationship between the hindrance factors and the function of BIM.

• Smart Media Journal
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• v.9 no.3
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• pp.107-115
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• 2020

Recently, BIM has become mandatory in the construction field, research on various use cases is increasing. In particular, when virtual reality technology, one of the core technologies of the 4th industrial revolution, and BIM are combined, it can be used in various fields such as preliminary design review and construction simulation. Until now, however, virtual reality grafting technology is only used as a simple prototype or as a model house. Also, it is difficult to activate virtual construction because it is expensive to produce high-quality virtual reality contents. Therefore, in this paper, in order to increase the utilization and quality of the virtual construction field, a study was conducted to shorten the material mapping time, which takes a lot of time when producing virtual reality contents using BIM. To this end, object properties were assigned to enable material mapping in the BIM model, and materials most used in the construction field were configured, and automated material function development and final tests were conducted that automatically map properties and materials. For the test, 10 models were used and the test was repeated three times, and the productivity improvement of about 50.16% was finally achieved. In the future, we plan to conduct research on physical data weight reduction based on the advanced material mapping automation function and the large-capacity BIM model.