• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.320-331
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• 2016

Linze-Donawitz gas (LDG) adjunctively produced in the steel mill contains over 60% of CO. Two processes that recover high purity CO from LDG were considered: COSORB and CO-Pressure swing adsorption (PSA). This study aimed to decide which one is more economically feasible than the other by techno-economic analysis (TEA). From the technical point of view of TEA, the process flow diagram (PFD) was constructed, the mass and energy balances were calculated, and the equipment type and size were determined in order to estimate the total capital investment (TCI) and the total production cost (TPC). From the economic point of view of TEA, economic performance such as return on investment (ROI) and payback period (PBP) was evaluated, and the sensitivity analysis was carried out to identify key factors influencing ROI and PBP. It was found that CO-PSA is more economically feasible due to higher ROI and lower PBP. The CO price highly influenced ROI and PBP.

• Journal of architectural history
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• v.18 no.2
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• pp.47-63
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• 2009

This study focused on changes in form and spatial uses of Urban Hanok in Bukchon, Seoul. There are 10 representative cases which have been renovated through the policy of 'Preservation & Regeneration of Bukchon' by Seoul metropolitan government and other experts. Changes in form and spatial uses of Urban Hanok in Buckon are as follows. First, Changes of scale. Trough removing extension parts, facade of renovated Hanoks are 'transformed' into recovering their identity. Using basements or lofts, intensive application of spaces is transformation which promotes the vitality of Hanoks. Second, changes of space organization. As Hanok changes its function from residence to commercial or cultural use, il a1so changes space character or reorganizes space organization. It is important that deciding function of Hanok has to adjust its scale and organization. Third, changes of construction performance. Through introducing new material and constructing method, performance of wall has been changed respecting its wooden structure and interior-exterior figure. However, technical studies must back it up not to destroy its value of eco-friendly architecture. Fourth, changes of facility systems, like floor heating system. They changes floor level of Hanok equally, and then sections of Hanok have became simple. Furthermore, inserting new facility space, such as boiler room, stand-up kitchen, bathroom and toilet, organization of space also changed. It is necessary that wise alternative proposal through the method of transformation or mutation must be presented. These four changes can be classification into method of 'transformation' and 'mutation'. Changes of scale are method of transformation and changes of space organization are method of mutation. Also, while changes of construction performance are mutation, changes of facility systems are transformation. Recently, as price of lots have been increased, a lot of Hanoks have been commercialized. Thc commercial energy threat 'the identity of Bukchon as residential area'. From now on, to operate 'identity' and 'vitality' complementary, it is necessary to make up for the preservation policy of Hanok and consolidate renovating standards of Hanok which correspond to character of particular region and building usage.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.5
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• pp.542-547
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• 2015

Since the oil price has been significantly jumped for several years, a heavy oil of low quality has been mainly used in the diesel engine of the merchant ship. Thus, a combustion chamber of the engine has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas of the combustion chamber has been getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of the engine parts such as exhaust valve, piston crown and cylinder head surrounded with combustion chamber are more serious compared to the other parts of the engine. Therefore, an optimum repair welding for these engine parts is very important to prolong their lifetime in a economical point of view. In this study, Inconel 625 filler metal were welded with GTAW method in the cast steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected and base metal zones were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% $H_2SO_4$ solution. The weld metal and base metal zones exhibited the highest and lowest values of hardness respectively. Furthermore, the corrosion current density of the weld metal zone revealed the lowest value, having the highest value of hardness. The corrosive products with red color and local corrosion like as a pitting corrosion were considerably observed at the base metal zone, while these morphologies were not wholly observed in the weld metal zone. In particular, the polarization characteristics such as impedance, polarization curve and cyclic voltammogran associated with corrosion resistance property were well in good agreement with each other. Consequently, it is suggested that the mechanical and corrosion characteristics of the piston crown can be predominantly improved by repair welding method using the Inconel 625 electrode.

• Journal of Internet Computing and Services
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• v.18 no.1
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• pp.57-64
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• 2017

Recent automobile manufacturing technology has improved not only the function and performance of cars, but also the audio systems in cars so as to increase their marketability. Automobile manufacturers always have the option of simply installing an expensive acoustic system to help customers enjoy a high-level sound quality car audio system. However, this also tends to increase the MSRP (Manufacturer's Suggested Retail Price) of the car. Therefore, it is desirable, where possible, to enhance the sound quality of plainer, less expensive audio devices to help customers feel as if they have a high-quality and expensive audio device in their car. In order to make this happen, the manufacturer must develop an optimal interior environment and audio system at a relatively lower cost. To this end, features of the car audio system can be enhanced by analyzing audio frequency response and using performance metrics to figure out the characteristics of the human auditory system. This study analyzed the sound field of Korean Recreation Vehicles (RVs) using the Internet of Things (IoT) sensor for the measurement of car audio system. As a result, high energy of sensitive bandwidth, one of the human auditory characteristics often makes annoying sound. This study also found that increasing the frequency response flatness is required by taking human auditory field into account when designing the car audio system for the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.117-124
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• 2017

A Smart Grid is a system that can efficiently use energy by exchanging real-time information in both directions between a consumer and a power supplier using ICT technology on an existing power network. DR(Demand response) is an arrangement in which electricity users can sell the electricity they save to the electricity market when the price of electricity is high or the power system is crisis. In this study, we developed a power meter data transmission device and power IT system that measure the demand information in real-time using a smart meter and transmit it to a cloud server. The power meter data transmission device developed in this study uses alight sensor connected to a Raspberry Pi 3 to measure the number of blinking lamps on the KEPCO meter per unit of power, in order to provide reliable data without any measurement errors with respect to the KEPCO power data. The power measurement data transmission device uses the standard communication protocol, OpenADR 2.0b. The measured data is transmitted to the power IT system, which consists of the VEN, VTN, and calculation program, via the LTE WiFi communication network and stored in its MySQL DB. The developed power measurement data transmission device issues a power supply instruction and performs a peak reduction DR when a power system crisis occurs. The developed power meter data transmission device has the advantage of allowing the user to adjust it every 1 minute, where as the existing smart metering time is fixed at once every 15 minutes.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.639-643
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• 2007

The use of forest biomass resources produced by forest tending and residual forest biomass that was not gathered on commercial thinning or cutting area was estimated to be come into the spotlight as bioenergy sources in these days of new high oil price. With considering these problems, This study was investigated about possibility with biomass calculation and convertibility to fossil fuel in these area. Total forest tending area in the year 2005 was 294, 115 ha and the yield gathered from these area was $143,747m^3$. It is equivalent to biomass of 115,000 ton and caloric value of 533,199Gcal. However, the potential and additional yield that is residual in forest stands was 2,483,000 ton. It is equivalent to 11,133 billion won of oil which is 20 times of the actual yield produced by forest tending. Therefore, these amount of biomass has a substitution effect of the fossil fuel. Moreover, the residual biomass that is not gathered at commercial thinning and cutting area was 475,000 ton. It is equivalent to 2,206,235 Gcal of heating value and about 2,211 billion won of oil. This potential amount could be a new energy source to be a substitution effect of fossil fuel. It is time to be interested in the forest biomass as a renewable and environment-friendly resource and its substitution effect of fossil fuel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.590-595
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• 2016

The US is pursuing a plan to raise the subsidies for electric vehicles by more than 30%. The number of electric vehicles in Europe is expected to be one million by 2020 and 2030 and there are plans to expand in the center of Germany to supply six million electric vehicles on the dissemination and development policies. The development of the electric vehicle is not simply a technical trend but there is the potential to improve the access to this technology and the possibility of changing the entire social system and long-term energy security. Domestic competition is also increasing the supply of electric vehicles, as new blue ocean markets are emerging. The current domestic On-board Charger (Home Charger) plans to be suspended from the 2015 government-sponsored installation, This paper on the IEC 61851-1 and IEC 61851-22 specifications analyzes the development of a midnight electricity charger as a low-cost algorithm, the decrease in price and the improved convenience of the On-board Charger for Bluetooth module with the ATmega128 existing charger system, and the UI configuration via the LCD Panel to a Smartphone app are proposed.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.18
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• pp.27-62
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• 2002

The international sale contract is the central contracts in export-import transactions. A good sale contract or set of general conditions of sale will cover all the principal elements of the transaction, so that uncertainties are avoided. The parties' respective duties as concern the payment mechanism, transport contract and insurance responsibilities, inter alia, will all be clearly detailed in the contract. The following key clauses should be included in international contracts of sale and general conditions of sale: ${\bullet}$ preamble ${\bullet}$ identification of parties ${\bullet}$ description of goods ${\bullet}$ price and payment conditions ${\bullet}$ delivery periods and conditions ${\bullet}$ inspection of the goods - obligations and limitations ${\bullet}$ quantity or quality variations in the products delivered ${\bullet}$ reservation of title and passing of property rights ${\bullet}$ transfer of risk - how accomplished ${\bullet}$ seller's warranties and buyer's complaints ${\bullet}$ assignment of rights ${\bullet}$ force majeure clause and hardship clause ${\bullet}$ requirement that amendments and modifications be in writing ${\bullet}$ choice of law ${\bullet}$ choice of dispute resolution mechanism Under most systems of law, a party can be excused from a failure to perform a contract obligation which is caused by the intervention of a totally unforeseeable event, such as the outbreak of war, or an act of God such as an earthquake or hurricane. Under the American commercial code (UCC) the standard for this relief is one of commercial impracticability. In contrast, many civil law jurisdictions apply the term force majeure to this problem. Under CISG, the standard is based on the concept of impediments to performance. Because of the differences between these standards, parties might be well advised to draft their own force majeure, hardship, or excusable delays clause. The ICC publication, "Force Majeure and Hardship" provides a sample force majeure clause which can be incorporated by reference, as well as a hardship clause which must be expressly integrated in the contract. In addition, the ICC Model provides a similar, somewhat more concise formulation of a force majeure clause. When the seller wishes to devise his own excusable delays clause, he will seek to anticipate in its provision such potential difficulties as those related to obtaining government authorisations, changes in customs duties or regulations, drastic fluctuations in labour, materials, energy, or transportation prices, etc.

• Journal of the Mineralogical Society of Korea
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• v.23 no.3
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• pp.199-209
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• 2010

Coal gasification technology in the sector of domestic clean coal technologies is being into the limelight since recent dramatic rise of international oil price. In this study, we used a low rank coal from Inner Mongolia, China as a starting material for gasification. Various properties including optical, mineralogical, X-ray spectroscopic, X-ray diffraction, and drying property were measured and tested in order to estimate the suitability of the coal to gasification. The coal was identified as a brown coal of lignite group from the measurement of vitrinite reflectance. The coal has very low slagging and fouling potentials, and the ignition temperature is about $250^{\circ}C$. The major impurities consist of quartz, siderite, and clay minerals. Additionally, the coal had moisture content above 28%. Tests for finding effective drying method showed that the microwave drying is more effective than thermal drying.

• Journal of the Korean Institute of Gas
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• v.18 no.4
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• pp.13-20
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• 2014

In natural gas distribution system, gas pressure is regulated correspond to requirement using throttle valve which is releasing huge pressure energy as useless form. The waste pressure can be recovered by using turbo machinery devices such as a turbo expander. In this process, excessive temperature drop occurs due to Joule-Thompson effect during the expansion process. Installing natural gas boiler before or after the turbo expander prevents temperature drop. Fuel cell or gas engine hybrid system further improve the efficiency, but 1~2% of total transporting natural gas is used for operating the hybrid system. In this study, a heat pump system is proposed as a preheating device which can be operated without using transporting natural gas. Thermodynamic analysis on evaporating and condensing temperatures and refrigerants is conducted. Results show that R717 is proper refrigerant for the hybrid system with high COP and low turbine work within the defined operating conditions. In domestic usage in Korea, the heat pump system has more economic feasibility owing to natural gas being imported with a high price of LNG form.