• 한국표면공학회지
• /
• 제34권2호
• /
• pp.115-124
• /
• 2001

Gas wiping process of continuously hot-dip galvanized coating on steel strip has noise and coating problems. To improve the qualify of product, characteristics of air flow on the steel surface must be investigated. In this paper, fluid dynamic model of the gas flow is setup and solved numerically using STAR-CD. The effects of edge baffle, distance between steel plane edge and baffle, inlet pressure, and gap between air knife and strip steel surface are investigated, and it is concluded that edge baffle can reduce over-coating and edge built-up.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.421-426
• /
• 2005

For the air-conditioner, refrigerant induced noise and vibration should be the problem when it reduced airflow rate in order to reduce the noise at low mode. With the test, it could be verified that one of the main reason for refrigerant induced noise were the velocity and flowing induced force of the refrigerant at the inlet of evaporator. So in order to reduce this velocity with same mass flow rate of refrigerant, quality at the evaporator inlet should be minimized. And in order to reduce flowing induced force of the refrigerant, flowing direction change should be eliminated. So in this paper, it would like to review the characteristics of refrigerating cycle at first and find how the quality and flowing induced force can be minimized.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
• /
• pp.373-378
• /
• 2002

The waterproofing system's performance is known to show a determining by complex interaction of material factors, design details, and the qualify of construction, and the waterproofing integrity of waterproofing membranes is determined by the bond to the deck and the amount of damage to the waterproofing membrane. In this research, the basic properties of waterproofing membranes on market and the tensile adhesive characteristics of waterproofing systems of concrete bridge deck have also been investigated in the view of the damages frequently reported from job site. As a results of tensile adhesive strength of waterproofing system, tensile strength is decrease with surface moisture contents except for inorganic-elastomeric liquid waterproofing membrane, and increase with strength of deck slab. Also tensile adhesive strength is generally increase in case of moisture curing of specimen because of pore structure and surface leveling. The after asphalt concrete paving tends to increase more than before those. The results of the liquid waterproofing membranes are upside-down, and the more concrete has strength, the more strength of tensile adhesive increase. The ambient temperature and the rolling temperature of asphalt concrete when application of the waterproofing membrane has considerable influence on the performance of waterproofing system.

• 한국건설관리학회:학술대회논문집
• /
• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
• /
• pp.616-619
• /
• 2004

건설사업의 목표는 해당 사업의 특성에 따라 우선순위의 차이는 있지만 기본적으로 원가절감, 공기단축, 품질확보로 압축될 수 있다. 그 중 원가절감은 발주자와 건설산업계 모두에게 중요한 목표이며 이를 달성하기 위한 전략과 방법은 중요한 관심사라 하겠다. 원가절감은 사업범위, 품질, 안전, 상호 비즈니스 관계, 고객만족 등 타 매니지먼트 요소의 희생을 수반함으로써 부정적인 이미지로 인식되어 왔다. 그러나 원가절감이란 용어는 부정적인 이미지를 극복하고 가치창조(value for money)를 달성시키는 긍정적인 방향으로 변화하여야 할 것이다. 본 연구에서는 영국 Constructing Excellence의 성공사례를 중심으로 원가절감의 성공사례 분석을 동하여 긍정적인 원가절감 전략의 특징을 도출하고자한다.

• 한국식품조리과학회지
• /
• 제19권6호
• /
• pp.694-700
• /
• 2003

Changes in the Qualify Properties of Doenjang Prepared using the Powder or extracts of Paecilomyces japonica were investigated during fermentation at 20$^{\circ}C$. The moisture content was increased during fermentation but was not significantly different in all treatments. The pH of Doenjang with p. japonica was lower than the control group and decreased with the fermentation time. The amino nitrogen content increased gradually for up to 60 days and decreased slightly at 90 days. The L, a and b value decreased in proportion to the fermentation period and those of Doenjang with P. japonica powder were the lowest. From the results of the sensory evaluation, the color of the control group was similar to "yellow" but that of the Doenjang made from powder of P. japonica was close to "dark brown" and those of the Doenjang made from the P. japonica extract were darker than that of the control group. The texture was "glossy and smooth" in all cases and preference about the texture was high. The Doenjang with added P. japonica Powder had a saltier taste and the Doenjang with P. japonica Powder had the least sweet taste. In the flavor and overall Preference, the Doenjang with P. japonica powder was the lowest.

• 한국공작기계학회논문집
• /
• 제15권2호
• /
• pp.51-58
• /
• 2006

Laser welding of dissimilar metals has been widely used to improve a wear resistance and a corrosion resistance of the industrial parts. The objective of this research works is to investigate the influence of the process parameters, such as the welding for SM45C and STS304 with CW Nd:YAG lasers. The bead-on-plate welding tests are carried out for several combinations of the experimental conditions. In order to quantitatively examine the characteristics of the dissimilar welding, the welding quality of the cut section, stain-stress behavior and the hardness of the welded part are investigated. From the results of the investigation, it has been shown that the optimal welding condition without defects in the vicinity of the welded area and with a good welding qualify is 1600W of the laser power, 0.85m/min of welding speed and $4{\ell}/min$ of pressure for shielding gas.

• 한국연초학회지
• /
• 제19권1호
• /
• pp.33-39
• /
• 1997

Recently the method of basal compound fertilizer (N : P : K = 18.2 : 9.8 : 35.0) Placement has been changed from banding to broadcasting in tobacco cultivation. The effects of the compound fertilizer placement, level of fertilizer and additional urea application on the agronomic characteristics, two chemical compositions and physical Properties of burley tobacco(Nicotiana tabacum L. cv. KB 108) were investigated at Chonju Experiment Station, Korea Ginseng and Tobacco Research Institute in 1995-1996. Six treatments consisted of (1) band (method of fertilizer Placement) + In kg/10a(compound fertilizer) + 0(additional urea applied), (2) broadcast+140+0, (3) broadcast+140+25, (4) band+180+0, (5) broadcast+180+0, and (6) broadcast +180+25. The additional urea was applied at hilling. No significant differences were detected between banding and broadcasting method of compound fertilizer Placement in field 9rowth, wield, organoleptic qualify(price Per kilogram), chemical composition and Physical properties of cured leaf, The increased compound fertilizer by 30%(40k/10a) or the additional urea application by 25kg per 10a produced slightly higher yield than the recommended amount of basal compound fertilizer without additional urea application did. It also increased the total alkaloid content of cured leaf. It is recommended that no more basal fertilizer above the recommended amount and no additional urea application are needed in burley tobacco fertilization, even though the method of basal fertilizer placement being chanced from banding to broadcasting. Key words : Nicotiana tabacum, fertilizer placement, additional urea.

• 한국전기전자재료학회논문지
• /
• 제16권3호
• /
• pp.202-206
• /
• 2003

In this study, modified PbTi $O_3$ ceramics was manufactured to apply for 30MHz SMD type ceramic resonator with the variations of electrode weight. To investigate the effects of electrode weight on resonant characteristics of ceramic resonator using 3$^{rd}$ overtone thickness vibration mode, ceramic wafers for resonator were fabricated by evaporating electrode weights of 0.66, 1.765, 2.32, 3.87$\times$ 10$^{-4}$ g/c $m^2$ with silver, respectively. And then, SMD type ceramic resonators were fabricated with the size of 3.7$\times$3.1mm and electrode radius size of 0.77mm. With increasing electrode weight, resonant resistance was gradually decreased. At the electrode weight of 2.32$\times$10$_{-4}$ g/c $m^2$, mechanical quality factor( $Q_{mt3}$) and dynamic range(D.R) showed the maximum value of 2,152 and 49dB, respectively.

• 산업경영시스템학회지
• /
• 제11권18호
• /
• pp.71-80
• /
• 1988

Process capability implies the qualitative capability of a process, and it is necessary to specify the process capability by quantification and to evaluate the level with the specified standardizaion. But the process capability index is currently used to evaluate the performance of quality control activity. without considering the characteristics of process structure or the economy of management. Here the researcher would like to redefine process capability and emphasize its index may be used as the measure of managerial assessment and the objective of process quality control in full consideration of the economic aspects of process characteristics. Too little or too much process capability causes a loss of or excess. The proper economic level of process capability varies to each process. The procedure of taking the optimum process capability index is derived from the expected profit function, whereas each method is studied in cases of normal process with one-sided specification and two-sided specification. In addition, the process capability index is presented as a method of quality assurance. And an example is exhibited on wrapping process of 'A' company. The results of this study are summarized at follows. First, though the norminalization of the process capability index is possible by the existing methods, the optimum process capability index can vary to the situation of each process. So, the optimum process capability index which is suggested in this dissertation should be used as the standard to assess process capability. Second, the process capability index can take its effect not just in indicating quality control or managerial records but also in the management of high qualify assurance.

• Journal of Advanced Marine Engineering and Technology
• /
• 제29권4호
• /
• pp.399-406
• /
• 2005

Alloy 625 is used widely in industrial applications such as aeronautical aerospace, chemical, petrochemical and marine applications. Because of a good combination of yield strength. tensile strength, creep strength, excellent fabricability, weldability and good resistance to high temperature corrosion on prolonged exposure to aggressive environments. High qualify weldments for this material are readily produced by commonly used processes. But all of processes are not applicable to this material by reason of unavailability of matching, position or suitable welding filler metals and fluxes may limit the choice of welding processes. Recently, the flux cored wire is developed and applied for the better productivity in several welding position including the vortical position. In this study. the weldability and weldment characteristics of Alloy 625 are evaluated in FCAW weld associated with the several shielding gases($80\%Ar+20\%\;CO_2,\;50\%Ar+50\%\;CO_2.\;100\%\;CO_2$) in viewpoint of welding productivity. The results of the experimental study on corrosive characteristics of Alloy 625 are as follows; There is no remarkable difference among shielding gases. however they has a striking difference among corrosive solutions by results of distinguished density and time of corrosive solution. Generally, the shielding gases($80\%Ar+20\%\;CO_2$) was superior to the other gases on high temperature tensile and a low temperature impact. but all of the shield gases were making satisfactory results on corrosion test.