• Journal of the Korea Safety Management & Science
• /
• v.18 no.4
• /
• pp.107-114
• /
• 2016

The efficiency of the purchasing and procurement logistics is important in automotive industry. The rationalization of production system is directly impact on productivity and quality. For this reason importance of logistics is high. Despite we are continuously making effort, our country are still below the level than developed country on logistics efficiency. Rising labor costs is an important factor in increasing logistics costs. So workforce reduction in logistics department is a large part. We deal with A-company inbound logistics, especially procurement logistics in automotive logistics as research object. So in this study we do research on work load balance about workers. We do research on 1,475 kinds of components in procurement process. We applied work load balance algorithm on chassis, final, sequence, trim warehouses workers. According to number of workers and average M/H, algorithm is applied in two ways. After applied work load balance algorithm we reduced numbers of workers from 28 to 20 and improved worker load balance rate from 47.1% to 93.7%.

• Journal of Digital Convergence
• /
• v.17 no.7
• /
• pp.115-124
• /
• 2019

This study is an empirical study of 'the effect of the key factors of Smart Factory on management performance through internal environmental factors in small and medium enterprises'. The purpose of the research is to verify that the implementation of a Smart Factory affects the performance of management and contribute to the continued development of the company, and to suggest the national policy of expanding the deployment of a Smart Factory. The procedures were surveyed by working-level officials of small and medium-sized manufacturing companies with a Smart Factory and statistically analyzed with the SPSS and SMART PLS. The results of the study showed that first, the environmental factors within the company had a positive effect on the key components of the Smart Factory. Second, the key factor in Smart Factory has had a positive impact on management performance. The above evidence shows that the key factors in smart factory considering the environmental factors of an enterprise affect its management performance, thus laying the theoretical foundation for the performance of smart factory construction. In the future, we will study how to build a Smart Factory.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.46 no.spc
• /
• pp.31-38
• /
• 2023

In this study, in order to develop a method to efficiently inject essential nutrients necessary for plant growth into wood chips, which are simply used as soil covering materials in the agriculture, landscaping and horticultural industries, the atmospheric pressure dipping method and the vacuum pressure impregnating method are used to improve the plant nutrients injectability and impregnation amount were comparatively analyzed. Nutrient ingredients and 8 major heavy metal contents of wood chips injected with nutrients were analyzed, and soil covering effects were examined by covering wood chips injected with nutrients on soil. Comparing the dipping method and the vacuum pressure impregnation method, it took about 48 hours or more to inject 1,500 g or more of the nutrient aqueous solution into 1 kg of wood chips in the dipping method, but the vacuum pressure impregnation method could be impregnated in about 5 minutes. Components of the impregnated nutrients were detected in proportion to the diluted concentration. As a result of covering the wood chips developed in this study on soil, they showed weakly acidic pH, and the heat insulation and moisturizing effects during the winter season were evaluated to be superior to those of uncovered soil. In the future, wood chips impregnated with nutrients are expected to contribute to the more efficient use of waste wood resources and the long-term supply of nutrients essential for plant growth, reducing excessive use of chemical fertilizers and reducing costs.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.9
• /
• pp.918-926
• /
• 2010

A widget is a small application running by the users' favorite services, so they are provided with web contents without explicitly visiting the web site. Although widgets can be easily implemented with Open APIs, only a few web sites provide them because of refactoring the structures of web resource to supply Open APIs to the widget developers. This paper presents an Open API Proxy Server System for widget services. The system consists of two components: an Open API Source Code Generator and an Open API Proxy Server. The Open API Source Code Generator provides a Graphical User Interface (GUI) for users to generate the Open APIs of user's choice and sends the Open API source code generation request to the Open API Proxy Server. The Open API Proxy Server using the HTML Table Processing Library receives the HTML web page from web site and extracts useful information from the target HTML table. The proxy server converts the extracted data into the corresponding XML document which becomes available through the Open API. We verify the operation of the proposed system through experiments with the HTML tables in the example web sites.

• Economic and Environmental Geology
• /
• v.56 no.6
• /
• pp.887-897
• /
• 2023

Leading waste disposal countries, such as Sweden, Switzerland, and the United Kingdom, conduct safety assessments across all stages of High-Level Radioactive Waste Deep Geological Disposal Facilities-from planning and site selection to construction, operation, closure, and post-closure management. As safety assessments are repeatedly performed at each stage, generating vast amounts of diverse data over extended periods, it is essential to construct a database for safety assessment and establish a data management system. In this study, the safety assessment data management systems of leading countries, were analyzed, categorizing them into 1) input and reference data for safety assessments, 2) guidelines for data management, 3) organizational structures for data management, and 4) computer systems for data management. While each country exhibited differences in specific aspects, commonalities included the classification of safety assessment input data based on disposal system components, the establishment of organizations to supply, use, and manage this data, and the implementation of quality management systems guided by instructions and manuals. These cases highlight the importance of data management systems and document management systems for securing the safety and enhancing the reliability of High-Level Radioactive Waste Disposal Facilities. To achieve this, the classification of input data that can be flexibly and effectively utilized, ensuring the consistency and traceability of input data, and establishing a quality management system for input data and document management are necessary.

• Journal of the Korean Vacuum Society
• /
• v.18 no.4
• /
• pp.318-330
• /
• 2009

A high heat flux test facility using a graphite heating panel was constructed and is presently in operation at Korea Atomic Energy Research Institute, which is called KoHLT-1. Its major purpose is to carry out a thermal cycle test to verify the integrity of a HIP (hot isostatic pressing) bonded Be mockups which were fabricated for developing HIP joining technology to bond different metals, i.e., Be-to-CuCrZr and CuCrZr-to-SS316L, for the ITER (International Thermonuclear Experimental Reactor) first wall. The KoHLT-1 consists of a graphite heating panel, a box-type test chamber with water-cooling jackets, an electrical DC power supply, a water-cooling system, an evacuation system, an He gas system, and some diagnostics, which are equipped in an authorized laboratory with a special ventilation system for the Be treatment. The graphite heater is placed between two mockups, and the gap distance between the heater and the mockup is adjusted to $2{\sim}3\;mm$. We designed and fabricated several graphite heating panels to have various heating areas depending on the tested mockups, and to have the electrical resistances of $0.2{\sim}0.5$ ohms during high temperature operation. The heater is connected to an electrical DC power supply of 100 V/400 A. The heat flux is easily controlled by the pre-programmed control system which consists of a personal computer and a multi function module. The heat fluxes on the two mockups are deduced from the flow rate and the coolant inlet/out temperatures by a calorimetric method. We have carried out the thermal cycle tests of various Be mockups, and the reliability of the KoHLT-1 for long time operation at a high heat flux was verified, and its broad applicability is promising.

• Korean Chemical Engineering Research
• /
• v.51 no.2
• /
• pp.250-256
• /
• 2013

Gasoline generates organic acid and polymer (gum) by hydrocarbon oxidation depending on the storage environment such as temperature and exposure to sunlight, which can cause metal corrosion, rubber and resin degradation and vehicle malfunction caused by accumulation in fuel supply system. The gasoline which has not been used for a long time in bi-fuel (LPG-Gasoline) vehicle causes problems, and low octane number gasoline have evaporated into the field, but the exact cause has not been studied yet. In this study, we suggest a plan of quality management by investigating the gasoline oxidation behavior. In order to investigate the oxidation behavior of gasoline, changes of gasoline properties were analyzed at various storage conditions such as storage time, storage vessel type (vehicle fuel tank, PE vessel and Fe vessel) and storage circumstances (sunlight exposure and open system, etc.). Currently distributing gasoline and bioethanol blended fuel (blended 10%) were stored for 18 weeks in summer season. The sample stored in PE vessel was out of quality standard (octane number, vapor pressure, etc.) due to the evaporation of the high octane number and low boiling point components through the vessel cap and surface. Especially, the sunlight exposure sample stored in PE vessel showed rapid decrease of vapor pressure and increase of gum. Bioethanol blended fuel showed similar results as gasoline.

• Journal of Ecology and Environment
• /
• v.35 no.4
• /
• pp.259-267
• /
• 2012

Biomass changes, net primary production and transfer dynamics of dry matter in four subtropical humid montane grasslands at Ebbenadu, Korakundah, Thiashola and Wenlockdown in Nilgiri Biosphere Reserve (NBR), the Western Ghats, India, were investigated. Despite the early report of a higher density and dominance of $C_4$ species over $C_3$ species in these grasslands, no functional study of matter production had previously been carried out. Therefore, in order to determine the roles played by these two groups of species, the present study was attempted. The study revealed that the dry matter and net primary production contributed by $C_4$ species were much greater than those of its $C_3$ counterpart in all the grasslands. The turnover rate of aboveground dry matter for both $C_3$ and $C_4$ species was generally rapid, whereas it was slow for belowground parts, and litter components of $C_3$ and $C_4$ species together. In all grasslands, generally about 60% and 10% of the input were channeled to aboveground and belowground parts, respectively, by the $C_4$ species, whereas the $C_3$ species transferred only about 22% and 8% of dry matter to aboveground and belowground parts, respectively. The total disappearance of dry matter was 2.73, 2.10, 3.19, and $1.96\;g\;m^{-2}\;day^{-1}$ in Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands, which was 48.83%, 44.30%, 54.81%, and 41.09% of the total input, respectively, in these grasslands. This resulted in a considerable surplus dry matter production in all the grasslands studied. This balance sheet of dry matter in community function indicates that all the four studied grasslands were supporting the existing wild animals adequately in terms of pasture supply. The study further revealed that the stronger establishment of $C_4$ species rather than their $C_3$ counterparts, in terms of higher density and dominance, has driven them to play major roles in matter dynamics and system transfer functions in all the four grasslands studied. This fact evidenced that pasture from $C_4$ species for wild animals was determined to be higher in comparison to that of $C_3$ species.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.3
• /
• pp.421-432
• /
• 2020

This paper proposes a 2-kW solid-state power amplifier (SSPA) developed by employing power amplifier pallets designed using gallium-nitride high electron mobility transistors, which is used in S-band military radars and to replace existing traveling-wave tube amplifier (TWTA). The SSPA consists of a high-power amplifier module, which combines eight power amplifier pallets, a drive amplifier module, a digital control module, and a power supply unit. First, the amplifier module and component were integrated into a small package to account for space limitations; next, an on-board harmonic filter was fabricated to reject spurious components; and finally, an auto gain control system was designed for various duty ratios because recent military radar systems are all active phase radars using the pulse operation mode. The developed SSPA exhibited a max gain of 48 dB and an output power ranging between 63-63.6 dBm at a frequency band of 3.1 to 3.5 GHz. The auto gain control function showed that the output power is regulated around 63 dBm despite the fluctuation of the input power from 15-20 dBm. Finally, reliability of the developed system was verified through a temperature environment test for nine hours at high (55 ℃) / low (-40℃) temperature profile in accordance with military standard 810. The developed SSPA show better performance such as light weight, high output, high gain, various safety function, low repair cost and short repair time than existing TWTA.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.4
• /
• pp.56-66
• /
• 2021

In this study, a waste heat recovery system was devised and the performances of components incorporated to recover the heat generated during the processing of aerobic liquid-composting in a livestock manure treatment facility were analyzed. In addition, the availability of recovered heat was confirmed. The heat generated by liquid fermentation in the livestock manure treatment facility was also checked. Experimental temperatures were set at 35, 40, and 45 ℃ based on considerations of the uniformity of aerobic liquid-composting fermentation tank temperature and its operating range (34.5 ~ 43.9 ℃). Recovered heat energies from the combined heat exchanger, which consisted of PE and STS pipes, were 53.5, 65.6, 74.4 MJ/h, The heat pump of capacity 5 RT was heated at 95.6, 96.1, 98.9 MJ/h and the heating COPs of the pump were 4.53, 4.62, and 4.65, respectively. The maximum hot water production capacity of the heat exchanger assuming a fermentation tank temperature of 45 ℃ confirmed an energy supply of 56 360 kcal/day. The heating capacity of the FCU linked to the heat storage tank was 20.8 MJ/h, and the energy utilization efficiency was 96.1%. When livestock manure was dried using the FCU, it was confirmed that the initial function rate was reduced by 50.5 to 45.8 % after drying.