• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.29 no.5
• /
• pp.259-268
• /
• 2017

This paper proposes a hydrogen-based social economy derived from fuel cells capable of replacing fossil fuels and resolving global warming, It thus provides an entry for developing economically feasible social configurations to make use of bio-hydrogen production systems. Bio-hydrogen production works from the principle that microorganisms decompose water in the process of converting CO to $CO_2$, thereby producing hydrogen. This study parts from an analysis of an existing 157-ton class NA1 bio-hydrogen reactor that identifies the state of feedstock and reactor conditions. Based on this analysis, we designed a 1-ton class bio-hydrogen reactor process simulator. We carried out thermal analyses of biological heat reactions, sensible heat, and heat radiation in order to calculate the thermal load of each system element. The reactor temperature changes were determined by modeling the feed mixing tank capacity, heat exchange, and heat storage tank. An analysis was carried out to confirm the condition of the feed mixing tank, heat exchanger, heat storage tank capacity as well as the operating conditions of the system so as to maintain the target reactor temperature.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.2
• /
• pp.105-110
• /
• 2015

This study proposes the more improved mathematical model than conventional that for the 3-DOF Helicopter System in Quanser Inc., and checks the validity about the proposed model by performance comparison between the controller based on the conventional model and that based on the proposed model. Research process is next : First, analyze the dynamics for the 3-DOF helicopter system and establish the linear mathematical model. Second, check the eliminated nonlinear-elements in linearization process for establishing the linear mathematical model. And establish the improved mathematical model including the parameters corresponding to the eliminated nonlinear-elements. At that time, it is used for modeling that Particle Swarm Optimization algorithm the meta-heuristic global optimization method. Finally, design the controller based on the proposed model, and verify the validity of the proposed model by comparison about the experimental results between the designed controller and the controller based on the conventional model.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.3
• /
• pp.649-661
• /
• 1998

If there is redeveloping into the system applying the object-oriented paradigm, productivity Improvement of software through reuse would be accomplished and maintenance cost be reduced. When a procedure-oriented system is transformed to a type applying the object-oriented paradigm, various techniques are studied to extract objects from source code automatically or semi-automatically. However, it is not easy to extract conceptuat objects when those techniques are applied, This problem entails another problem which drops the conceptual integrity of the extracted objects. In this paper, we suggest an object extraction method and tool development to resolve the problem occurring at the time when thc pr"~r"m, dcveloped through procedure-oriented is transformed to an object-oriented system. The suggested method allow to extract the desired objects using object modeling for various application domains of the real world given source code and design recovery information. During the extraction process, functionality and global variables of the source code as well as its intcrface arc rigorously analyzed. This process can enhance the conceptual integrity of the objects and make easy to construct class hierarchies.

• Asian Journal of Business Environment
• /
• v.11 no.3
• /
• pp.33-43
• /
• 2021

Purpose: The purpose of the paper is to assess the greening of investment flows as well as the orientation of financial sources of effective environmental protection. Both India and Vietnam are considered to be two Asian countries that are radically affected by global climate change. Governments of the two countries have implimented numerous measures against environmental pollution through the banking and finance sector. Developing green banking operations in India and Vietnam is a new direction in the socio-economic development strategy coupled with effective environmental protection. Research design, data and methodology: The data was mainly based on Asia Development Bank Institution (ADBI) and Bank of India (BOI) from 2015 - 2018. This paper focused on comparing and evaluating the development of green banks between the two countries. Result: The banks' contribution to green growth and green economy is shown in two basic aspects: (i) the connection between organizations, and individuals, and management process for investment projects, including environmental risks; and (ii) the operation of banks has a direct impact on the environment, through the application of technology to pay documents and apply e-banking. Conclusion: Paper reflects, compares and evaluates green banking operations in India and Vietnam to provide new directions aiming to develop financial and economic system along with effective and efficient step toward climate change control. India's green banking operations, after a specific assessment, will be lessons for the Government of Vietnam during the process of socio-economic development and environmental protection.

• Journal of Environmental Analysis, Health and Toxicology
• /
• v.21 no.4
• /
• pp.209-219
• /
• 2018

In the areas of RoHS, WEEE, ELV and REACH, reinforcement of environmental regulations against harmful substances is a global trend not only in EC but also in all over the world. In the fields of Korea's major export products such as material parts, electrical and electronic products and automobile parts, we are responding to these regulations consistently. To develop reference material for analyzing lead and cadmium in paints, the candidate materials were produced through the screening process which separated shapes and sizes. To secure the traceability of the candidate materials produced, the characteristics and uncertainties are estimated by ICP-AES analysis using the primary reference material. The short-term and long-term stabilities also are evaluated in parallel. In order to calculate the final certification value of the candidate material, the verification were carried out by the performance evaluation through the comparison among the KOLAS (Korea Laboratory Accreditation Scheme) laboratories, and the CRM was produced in accordance with ISO Guide 35. The certified values and uncertainties of Pb and Cd of the final paint standard, determined according to the joint analysis among laboratories, are Pb [($191.4{\pm}3.1$) mg/kg, ($944.1{\pm}5.6$) mg/kg] and Cd [($45.0{\pm}2.6$) mg/kg, ($225.5{\pm}3.5$) mg/kg]. These standard materials were developed to enhance the reliability of measurement analysis, including the validity and traceability of measurement results. Also it is expected that the CRM will be used as QCM (quality control material) for the product design and the process monitoring, so that regulation and management of hazardous heavy metals can be systematically implemented.

• Journal of the Korean Society of Industry Convergence
• /
• v.24 no.6_2
• /
• pp.899-908
• /
• 2021

It is expected that the global market for vessel repair and remodeling will grow up to the scale of about 25 billion dollars by 2023. Korea's shipbuilding industry is leading the world with its international competitiveness in design and production technology. The actual status of vessel repair industry, however, is poor as there are only two or three companies for vessel repair that can deal with large vessels in the area of Gyeongnam. The reason is that civil complaints are filed severely about environmental problems and environment-related regulations are so strict that it is fairly hard to get governmental approval for the operation of a vessel repair workplace. Domestic vessel repair companies mainly target small- and medium-sized vessels. There are only few workplaces that can carry out regular examination or repair work on large vessels such as LNG vessels, and due to the high price of vessel repair, most of the domestic repair work on large vessels including LNG vessels tends to be snatched by markets in Southeast Asia or China. Despite the tremendous domestic demand of Korea that has established the world's first shipbuilding industry and world's sixth biggest harbor infrastructure, its vessel repair industry can be said to be in very poor condition. In order to vitalize vessel repair industry, this study is aimed to analyze the environmental influence of vessel repair workplaces in Gyeongnam where vessel repair companies are concentrated and suggest standard processes by analyzing vessel repair processes precisely.

• Journal of Korea Trade
• /
• v.23 no.7
• /
• pp.34-44
• /
• 2019

Purpose - The purpose of this study is to present what the port of Pyeongtaek, the hub of Korean trade with China, should improve in the current situation, wherein the e-commerce trade volume between Korea and China is increasing due to the development of online technology. Design/methodology - In this study, through prior research and expert interviews on e-commerce and port activation between borders, we derived the main improvement factors for 1) Administration and Systems, 2) Facilities, 3) Transport, and 4) Manpower, and selected 12 detailed variables for the major improvement factors. To identify the relative importance of the major improvement factors, the Analytic Hierarchy Process (AHP) method was applied, and a survey was conducted among 15 related experts. Findings - As a result, among the 12 detailed variables, Composition of Association (0.267) was the first factor to be improved, followed by Incentive Support (0.143) and E-Commerce Cluster (0.131). Based on these analyses, the main implications of this study are, first, in the current situation where the cross-border e-commerce market is growing, Pyeongtaek Port needs to form a consultative body among the government, local governments, and related businesses in connection with cross-border e-commerce and develop various support policies for the e-commerce market. Second, it will have to be able to provide differentiated services from competing ports by establishing e-commerce market-oriented clusters. Originality/value - In existing related studies, various improvements were presented to revitalize trade in line with the growth of the cross-border e-commerce market. However, with regard to most cross-border e-commerce businesses, one-dimensional improvement measures, such as improvement of payment systems, improvement of customs clearance services, and promotion of human resources, are presented in a piecemeal manner. In other words, none of the studies have proposed the importance and priority of each measure in terms of both the forward-looking and efficient allocation of resources, which is the purpose of this study. Therefore, this study contributed politically, practically, and academically by presenting countermeasures for ports to revitalize cross-border e-commerce and presenting strategic priorities using quantitative analysis methods.

• Journal of Korea Trade
• /
• v.24 no.8
• /
• pp.189-206
• /
• 2020

Purpose - This paper attempted to verify the process by which a multinational corporation (MNC)'s subsidiary practices entrepreneurship to create effective knowledge (KC) in the local market. We have looked at whether subsidiary entrepreneurship (SENT) has a moderation effect in creating knowledge for the local market when a subsidiary has been given autonomy (AUT) from the headquarters (HQ). We also argue that when a subsidiary creates meaningful knowledge, the effect of the increased status by the HQ within the MNC network position (NP) has an indirect effect on whether knowledge is transferred to other overseas subsidiaries (KTO). Design/methodology - This paper used a structural equation model (SEM) of 282 effective foreign companies invested in Korea. To test the hypothesis about the process of SENT on KTO, descriptive statistics, confirmatory factor analysis, reliability, convergent and discriminant validities, and common method bias were analyzed using STATA. In addition, the moderation effect was verified along with SEM. The moderation effect of AUT on SENT and KC was presented graphically by confirming \mathrm{\pm1} standard deviation of AUT for the main effect. Findings - Our findings are as follows. First, while the hypothesis about the direct effect of SENT and KC on KTO was not supported, all other hypotheses were supported. Second, both the AUT and moderating effect and the indirect effect of NP were significant. In the conclusion, these findings are discussed in relation to its various theoretical and practical implications. Originality/value - This study attempted to contribute to the knowledge creation theory of MNC by contemplating how subsidiaries can move away from HQ and grow in the local market. Although there is still a shortage of foreign investment in the Korean market, our practical implications offer guidance for how current subsidiaries can develop more than other overseas subsidiaries.

• Journal of Positioning, Navigation, and Timing
• /
• v.10 no.4
• /
• pp.315-333
• /
• 2021

Due to the Global Navigation Satellite System (GNSS) modernization, recently launched GNSS satellites transmit signals at various frequency bands such as L1, L2 and L5. Considering the Korean Positioning System (KPS) signal and other GNSS augmentation signals in the future, there is a high probability of applying more complex communication techniques to the new GNSS signals. For the reason, GNSS receivers based on flexible Software Defined Radio (SDR) concept needs to be developed to evaluate various experimental communication techniques by accessing each signal processing module in detail. This paper proposes a novel SDR-based A-GNSS receiver capable of processing multi-GNSS/RNSS signals at multi-frequency bands. Due to the modular structure, the proposed receiver has high flexibility and expandability. For real-time implementation, A-GNSS server software is designed to provide immediate delivery of satellite ephemeris data on demand. Due to the sampling bandwidth limitation of RF front-ends, multiple SDRs are considered to process the multi-GNSS/RNSS multi-frequency signals simultaneously. To avoid the overflow problem of sampled RF data, an efficient memory buffer management strategy was considered. To collect and process the multi-GNSS/RNSS multi-frequency signals in real-time, the proposed SDR A-GNSS receiver utilizes multiple threads implemented on a CPU and multiple NVIDIA CUDA GPGPUs for parallel processing. To evaluate the performance of the proposed SDR A-GNSS receiver, several experiments were performed with field collected data. By the experiments, it was shown that A-GNSS requirements can be satisfied sufficiently utilizing only milliseconds samples. The continuous signal tracking performance was also confirmed with the hundreds of milliseconds data for multi-GNSS/RNSS multi-frequency signals and with the ten-seconds data for multi-GNSS/RNSS single-frequency signals.

• Journal of Korea Trade
• /
• v.27 no.4
• /
• pp.1-18
• /
• 2023

Purpose - The purpose of this paper is to study how flexibility and mutuality in determining trade terms impact logistics efficiency in the context of relational theory. Additionally, the effect of relational contracts on logistical efficiency relative to the value of the goods being traded is investigated. Design/methodology - According to the relational contract theory, we developed 17 factors utilizing a 7-point Likert scale to measure variables related to flexibility, mutuality, logistics efficiency, and the added value of goods. The survey occurred over four months, and was distributed directly, and via email, phone, and online Google surveys. A total of 403 surveys were collected out of 1,800 distributed, and 380 were analyzed. The principal respondents were import/export companies and members of the Korea International Trade Association and the Korea Small and Medium Business Export-Import Association. The collected data were analyzed using frequency analysis, exploratory factor analysis, and correlation analysis using SPSS ver. 26.0 statistical software, and hypothesis test results were derived using Process Macro ver. 3.5. Findings - This study provides evidence that negotiation flexibility for trade terms affects the efficiency of the logistics process, and the mutuality of such arrangements is shown to be associated with the flexibility and efficiency of logistics processes. Additionally, it has been established that companies whose trade goods possess a low degree of added value may experience increased efficiency in logistics operations if they agree to trade terms that are both flexible and mutually beneficial with their counterparts. Originality/value - This study suggests that in an environment of rapidly shifting global logistics and unpredictable related costs, trade companies may be able to improve logistics efficiency by establishing flexible, mutually beneficial trade terms when entering into contracts. Furthermore, it is suggested that companies dealing in low-value-added products may improve the logistical performance of approaching trade from a perspective of relational contracts.