• The Journal of Industrial Distribution & Business
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• v.10 no.1
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• pp.29-37
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• 2019

Purpose - We study the dynamic linkages of the economic policy uncertainty (EPU) in the US on the manufacturing stock market returns in Korea. In detail, we examine the casual link between EPU index in the US and the manufacturing stock indexes in Korea. Research design, data, and methodology - We measure mainly the distribution effect of the US EPU on the manufacturing stock market in Korea of 1990-2017 by the vector error correction model (VECM). Result - In result, we estimate the impact of the US EPU index has significantly a negative response to the manufacturing stock market in Korea such as non-metal stock index, chemical stock index, food stock index, textile·clothes stock index, automobile·shipbuilding stock index, machinery stock index, steel·metal stock index. Also the remaining variables such as electric·electronics stock index, S&P 500, and producer price index in Korea have a negative relationship with US EPU index. Conclusions - We find out that the relationship between EPU index of the US and the manufacturing stock market in Korea has the negative relationships. We determine the EPU of the US has the spillover effect on the industry stock markets in Korea.

• Plant Journal
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• v.10 no.4
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• pp.29-34
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• 2014

In this consideration, this research investigated the piping design items and drew out key design items through interview with experts and surveys to apply them to actual project examples and look into piping design item-specific significance and cost variation ranges. Based on this investigation, the Monte-Carlo simulation was employed herein to analyze the cost variation range for the entire piping design costs with a view to presenting a way to calculate a reasonable bidding price for any similar project and verify the appropriateness of joining a bid.

• Analytical Science and Technology
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• v.6 no.2
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• pp.181-195
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• 1993

The purpose of this research is to improve the density and the hardness of the SUS alloys for wear resistant materials. The dependence of the density, shrinkage ratio and hardness of various alloys on the sintering temperature and composition were examined. Alloys added with 3% Ti shows the most proper sintering properties of shrinkage ratio and the hardness which is enough to substitute for existing high price materials.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.246-251
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• 2020

Dimethyl Ether(DME) engine use a highly efficient alternative fuel having a great quantity of oxygen and has a advantage no polluting PM gas. The existing DME fuel cam material is a highly expensive carbide alloy, and it is difficult to take a price advantage. Therefore the study of replacing body area with inexpensive steel material excluding piston shoe and contact area which demands high characteristics is needed. The development of WC-Ni base carbide alloy optimal bonding composition technique was accomplished in this study. To check out the influence of bonding temperature and time, bonding characteristics of sintering temperature was experimented. The hardness of specimen and bonding rate were measured using ultrasound equipment. The bonding state of each condition was excellent, and the thickness of mid-layer, temperature and maintaining time were measured. The mid-layer thickness according to bonding temperature and maintaining time were observed with optical microscope. We analyzed the micro-structural analysis, formation of bonding specimen, wafer fabrication and fuel cam abrasion test. Throughout this study, we confirmed that the fuel cam for DME engine which demands high durability against velocity and pressure is excellent.

• Journal of the Korean Institute of Rural Architecture
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• v.24 no.2
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• pp.29-36
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• 2022

This study analyzed the effects of building and greenhouse structural code on the structural design and the greenhouse construction cost. The over-design possibility of greenhouse was analyzed when building structural code was applied using standard smart greenhouse drawings. The possibility of decrease in greenhouse construction cost was investigated if the currently applied building structural code was replaced with greenhouse structural code. As a result of comparing the member sizes with the standard drawings, building structural code was designed with 13%~74% more steel than greenhouse structural code. When building construction estimate was replaced with greenhouse construction estimate, it was possible to reduce the total construction cost of the glass greenhouse by 17% and that of the vinyl greenhouse by 14%. Since there is no standard construction estimate suitable for greenhouses, the wage unit price is set excessively, and the construction cost of the smart greenhouse is increasing. In conclusion, it is necessary to establish greenhouse structural code and greenhouse construction estimate to lower the greenhouse construction cost.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.11-18
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• 2017

The purpose of this survey was to collect basic data on breeding systems of animal welfare-approved laying hen farms in Korea. Questionnaires were mailed to 64 animal welfare-approved farms, and 20 questionnaires (31.3%) were returned. The housing systems were fabric coverlet (4 farms, representing 20%), naturally farmed (Yamagisi, 7 farms, 35%), and steel panel-framed housing (9 farms, 45%). The 20 farms had stocking densities of $2{\sim}3birds/m^2$ (2 farms; 10%), $4{\sim}5birds/m^2$ (10 farms; 50%), and $6{\sim}7birds/m^2$ (8 farms; 40%). Breeding methods were floor-housed (14 farms; 70%), free-range (3 farms; 15%), and floor plus free-range (3 farms; 15%). Stocking density was $4{\sim}6birds/m^2$ at most of the farms with fabric coverlet and naturally farmed housing and $6{\sim}7birds/m^2$ at seven farms (of 9 farms) with a steel panel-framed housing. The daily feed intake of 11 farms (55%) was between 120 and 130 g, which included 3 farms (15%) with fabric coverlet, 3 farms (15%) with naturally farmed housing, and 5 farms (25%) with steel panel-framed housing. The age of peak production was 24~28 weeks overall 20 farms. Over 80% of production on fabric coverlet, naturally farmed, and steel panel-framed house farms was on 3, 4 and 6 farms, respectively. Respiratory disease on the 20 farms represented 55% of total disease incidence, and of each housing type represented 75% (fabric coverlet), 70% (naturally farmed) and 33% (steel panel-framed). E. coli disease was only found in the steel panel-framed housing. Most of the animal welfare-approved eggs were sold at large markets or a real sale markets. Egg price was 200~250 won per egg. These results indicate the current situation of animal welfare-approved farms and could be caused that windowless poultry house was applied to animal welfare approved farms.

• Journal of the Korea Concrete Institute
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• v.20 no.1
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• pp.59-66
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• 2008

This study is about manufacturing and producing girder, which is an essential component of bridge structure, in a composite of FRP + concrete. This has a higher competitive power in price than steel girder. The girder used in this study is made of glass fiber which has a lower elastic modulus than steel and thus has some technical limitations such as excessive deflection compared to steel girder and lack of production facilities in FRP production companies to make a large-section component material. Thus, this study suggested a section of a new module that will allow for applying a large section in order to solve the technical difficulties mentioned above and to secure low stiffness of FRP, developed a new FRP+concrete composite girder that is filled with the appropriate amount of concrete. To identify the structural behavior of this FRP+concrete composite girder, experiments were conducted to measure its flexural strength according to the difference in the strength of confined concrete and the existence of stud. The results of the flexural strength test confirmed the composite effect from confining concrete and the effect of increase in strength proportional to the strength of concrete. In developing FRP+concrete composite girder, NDT study was also conducted to analyze the interface characteristics of concrete and FRP.

• 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 Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.409-417
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• 2014

Since the oil price has been significantly jumped for recent some years, the diesel engine of the merchant ship has been mainly used the heavy oil of low quality. Thus, it has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas in a combustion chamber is getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of most parts surrounded with combustion chamber is more serious compared to the other parts of the engine. Therefore, an optimum weldment for these parts is very important to prolong their lifetime in a economical point of view. In this study, four types of filler metals such as Inconel 625, 718, 1.25Cr-0.5Mo and 0.5Mo were welded with SMAW and GTAW methods in the forged steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected zone and base metal were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% H2SO4 solution. The weld metal and base metal exhibited the best and worst corrosion resistance in all cases of filler metals. In particular, the weld metal welded with filler metals of Inconel 718 revealed the best corrosion resistance among the filler metals, and Inconel 625 followed the Inconel 718. Hardness relatively indicated higher value in the weld metal compared to the base metal. Furthermore, Inconel 625 and 718 indicated higher values of hardness compared to 1.25cr-0.5Mo and 0,5Mo filler metals in the weld metal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.865-871
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• 2011

Presently, the location and direction information are certainly needed for the autonomous vehicle of the ship. Among them, the direction information is a essential elements to automatic steering system. And the gyro-compass, the magnetic-compass and the GPS compass are the sensor indicating the direction. The gyro-compasses are mainly used in the large-sized ship of the GMDSS(Global Maritime Distress & Safety System). The precision and the reliability of the gyro-compasses are excellent but big volume and high price are disadvantage. The magnetic-compass has relatively fine precision and inexpensive price. However, the disadvantage is in the influence by the magnetism object including the steel structure of a ship, and etc. In the case of the GPS compass, the true north is indicated according to the change of the location information but in case of the minimum number of satellites or stopping of a ship or exercise in the error range, the exact direction cannot be obtained. In this paper, the performance of the GPS compass was improved by using the least-square curve fitting method for the mutual trade off of the angle sensor. The algorithm which improves the precision of an azimuth by applying the weighted value according to the size of covariance error was proposed with GPS-compass and magnetic compass. The characteristic and the performance of the proposed algorithm were analyzed and verified through experimentation. The applicability of the proposed algorithm was shown through the experimental result.