본 연구에서는 점근해석 및 논로컬 이론에서 요구하는 4차 이상의 고차 미분근사를 수행하기 위하여 계방정식에 혼합변분이론을 적용하여 MLS 차분법으로부터 구해지는 고차 미분근사의 정확도를 큰 폭으로 향상시킨다. 또한, MLS 차분법에 존재하는 세 가지 조건변수에 따른 고차미분근사의 정확도를 비교·분석한다. 혼합변분이론의 합응력을 후처리하여 변위의 미분을 근사할 경우 기존의 변위장 기반 계방정식의 차분 결과에 비해 미분 차수가 2차 낮아진다. 해석 범위내 절점 수가 과도하게 많거나 기저 차수가 클 경우 MLS 차분법의 영향영역 내에서 과적합(overfitting)이 발생한다. 또한 영향영역이 최적 범위 이상으로 넓어질 경우 근사의 정확도가 떨어진다. 위 내용을 사인 하중을 받는 단순지지보 수치예제로부터 확인하였다.

In this study, the case of brand IMC communication of LG Hausys’ total interior solution brand Z:IN was dealt with. The target consumer of the Z:IN brand is a general end consumer and also shows the character of industrial goods. Accordingly, there should be a unique aspect that brand management and communication methods must be made from more angles. For many companies which are active in the industry, this case study should be significant. This case study was researched in terms of consumer’s purchase decision-making process and consumer participation and experience. Brand Zi:in developed a brand communication strategy following the flow of the consumer purchasing decision process. And the brand actively induces consumer experience and participation so that consumers can communicate more closely with the brand. Brand communication from the perspective of consumer purchasing decision-making and consumer experience and participation is a crystal that fully considers LG Hausys’ products, markets, and competitors, and will be an effective strategy to continue to preoccupy the market not only in the present but in the future.

Machines and facilities are physically or chemically degenerated by continuous usage. One of the results of this degeneration is the process mean shift. The representative type of the degeneration is wear of tool or machine. According to the increasing wear level, non-conforming products cost and quality loss cost are increasing simultaneously. Therefore a periodic preventive resetting the process is necessary. The total cost consists of three items: adjustment cost (or replacement cost), non-conforming cost due to product out of upper or lower limit specification, and quality loss cost due to difference from the process target value and the product characteristic value among the conforming products. In this case, the problem of determining the adjustment period or wear limit that minimizes the total cost is called the ‘process mean shift’ problem. It is assumed that both specifications are set and the wear level can be observed directly . In this study, we propose a new model integrating the quality loss cost, process variance, and production volume, which has been conducted in different fields in previous studies. In particular, for the change in production volume according to the increasing in wear level, we propose a generalized production quantity function g(w). This function can be applied to most processes and we fitted the g(w) to the model. The objective equation of this model is the total cost per unit wear, and the determining variables are the wear limit and initial process setting position that minimize the objective equation.

Aftermarket refers to a market in which a company sells complementary goods, replacements of parts, and upgrade or maintenance services to consumers after selling them main durable goods. Intuitively, consumers who purchase main durable goods become major potential customers in subsequent aftermarket. Thus the existence of the aftermarket has a significant impact on pricing of the main durable goods as well as the aftermarket products. In this study, we analyze the effect of aftermarket on the pricing strategy for a company selling both main durable goods and aftermarket products. To do this we first divided the market into markets where the aftermarket products are indispensable and optional. Based on the proposed market types, the profit maximizing solutions are derived using two-period model, and the impacts of consumers’ undervaluation of aftermarket product prices on pricing strategy are analyzed. The results can be summarized as follows : (1) Regardless of the market type, the total profits were found to be inversely proportional to the consumer’s awareness accuracy of product prices in the aftermarket. This is in line with marketing efforts that sales companies have made intuitively to make consumers underestimate the cost of the aftermarket. (2) If aftermarket product is indispensable, only revenue from the aftermarket is sought. On the other hand, if aftermarket product is optional, revenue from the main durable good as well as the aftermarket product will be sought simultaneously. (3) Moreover, when aftermarket product is optional, the lower the awareness accuracy of consumers, the higher the price and profit of the main durable goods, while the lower the price and profit of the aftermarket products. This is contrary to the intuition that the lower the consumer's valuation of the costs of aftermarket, the more advantageous it would be to rely on aftermarket products rather than on main durable goods.

This paper presents a method to measure the similarity of assigned jobs in the gravure printing operation based on the chromaticity and color sequence, and order the jobs accordingly. The proposed dispatching rule can be used to fulfill diverse manufacturing site requirements because the parameters can be adjusted to prioritize chromaticity and color sequence. In general, dispatching rules either ignore the job-changing time or require that the time be clearly defined. However, in the gravure printing operation targeted in this study, it is difficult to apply the general dispatching rule because of the difficulties in quantifying the job-changing time. Therefore, we propose a method for generalizing assignment rules of the job planner, allocating relative similarity among assigned jobs, and determining the sequence of jobs accordingly. Chromaticity priority is determined by the arrangement of the color assignments in the printing operation; color sequence priority is determined by the addition, deletion, or change in a specific color sequence. Finally, the job similarity is determined by the dot product of the chromaticity and color sequence priorities. Implementation of the proposed dispatching rule at an actual manufacturing site showed the planner present the same job order as that obtained using the proposed rule. Therefore, this rule is expected to be useful in industrial sites where clear quantification of the job-changing time is not possible.

Lu3Al5-xGaxO12:Ce3+,Cr3+ powders are prepared using a solid-state reaction method. To determine the crystal structure, Rietveld refinement is performed. The results indicate that Ga3+ ions preferentially occupied tetrahedral rather than octahedral sites. The lattice constant linearly increases, obeying Vegard’s law, despite the strong preference of Ga3+ for the tetrahedral sites. Increasing x led to a blue-shift of the Ce3+ emission band in the green region and a change in the emission intensity. Persistent luminescence is observed from the powders prepared with x = 2–3, occurring through a trapping and detrapping process between Ce3+ and Cr3+ ions. The longest persistent luminescence is achieved for x = 2; its lifetime is at least 30 min. The findings are explained using crystal structure refinement, crystal field splitting, optical band gap, and electron trapping mechanism.

Since sewer rehabilitation program requires long construction period and enormous capital investment, determination of rehabilitation priorities is important with systematic planning considering appropriate evaluation parameters. In this research, we applied PROMETHEE(Preference Ranking Organization METHod for Evaluations) known as very objective and scientific multi-criteria decision-making analysis, using the weights determined by AHP(Analytic Hierarchy Process) for the selected sewer evaluation items to calculate the rehabilitation priorities for each sewer sub-catchment in basin Gusan 1 of Seoul. Preference functions and preference thresholds were estimated for each criterion of ratio of lack of hydraulic capacity of sewers, defect ratio, ratio of sewers with velocity less than its minimum criteria, and density of sewers in the sub-catchment. As a result, it was found that region d had the first priority among four sub-catchments. For each and every sewer located in region d, we could also rank sewers to be rehabilitated urgently.

본 연구는 중국 상장기업의 정치적 연결과 국제 인수합병(Cross-border M&A) 거래 완료 가능성 사이의 관계를 실증분석한다. 정부의 영향력이 강한 중국에서는 기업이 보유한 중국 정부와의 정치적 연결이 중요한 경쟁 우위의 원천이 된다. 기업은 정치적 연결을 통해 인수 관련 투자 정보의 습득, 인수자금 지원, 그리고 규제의 탄력적 적용 등의 혜택을 얻을 수 있으므로 기업의 정치적 연결은 국제 M&A에 있어서 거래가 완료될 가능성을 높여줄 것이라 판단한다. 그러나 이러한 중국기업의 정치적 연결이 국제 M&A 거래 완료 가능성에 미치는 영향은 기업의 소유구조에 따라 다르게 나타날 수 있다. 정부의 영향력이 강한 국유기업은 정부의 대리인으로 인식되어 민영기업에 비해 현지국의 정당성 압력을 더 크게 받을 수 있기 때문이다. 이에 본 연구는 국유기업은 정치적 연결이 국제 M&A 거래 완료 가능성에 미치는 영향력을 약화시킬 것으로 보았다. 2006년부터 2017년 기간 동안 이루어진 353개 중국 상장기업의 국제 M&A 439건을 표본으로 실증분석을 실시한 결과, 기업의 정치적 연결은 국제 M&A 거래 완료 가능성과 유의한 정(+)의 관계를 갖는 것으로 나타났다. 또한 기업의 정치적 연결이 국제 M&A 거래 완료 가능성에 미치는 정(+)의 관계는 민영기업에 비해 국유기업에서 약화되는 것으로 나타났다. 본 연구는 국제 M&A 연구에서 상대적으로 많이 다루어지지 않았던 인수기업의 정치적 연결이 국제 M&A 거래 완료의 선행요인으로 작용할 수 있음을 실증분석을 통해 확인하였다.

한국에서 전통적인 과학기술인력 직업군의 경계는 빠른 속도로 허물어지고 있 다. 한편으로는 지식기반경제의 등장과 확장으로 과학기술이 전통적 활용영역을 넘어 확산 됨에 따라 과학기술인력 역시 다양한 융합분야로 진출하고 있으며, 동시에 고학력 인구의 비중에 비해 고급 직종의 비중이 상대적으로 낮은 데에서 기인한 하향취업이 그러한 경향을 가속화시킨다. 이 논문에서는 박사급 이공계 인력에 초점을 맞추어 직업구성의 변화 추이를 살 펴보고 그 결정요인을 실증적으로 분석하고자 한다. 구체적으로, 관련 직종을 전통적 과학기 술직업군과 기타 직업군으로 나누어 그 비중의 변화를 도출하며, 이러한 직업구조의 변화에 대한 영향요인을 분석한다. 분석에는 과학기술정책연구원의 ‘2012 박사인력활동조사' 데이터를 활용하였다. 분석 결과는 이공계 박사인력의 직업구성에 뚜렷한 변화가 일어나고 있음을 보여준다. 직업다변화는 공학보다는 이학 분야에서, 공공보다는 민간 분야에서, 그리고 신규 세대일수록 더 빠르게 진행되고 있었다.

NKN [(Na,K)NbO3] is a candidate lead-free piezoelectric material to replace PZT [Pb(Zr,Ti)O3]. A single crystal has excellent piezoelectric-properties and its properties are dependent of the crystal orientation direction. However, it is hard to fabricate a single crystal with stoichiometrically stable composition due to volatilization of sodium during the growth process. To solve this problem, a solid solution composition is designed (Na,K)NbO3-Ba(Cu,Nb)O3 and solid state grain growth is studied for a sizable single crystal. Ceramic powders of (Na,K)NbO3-M(Cu,Nb)O3 (M = Ca, Sr, Ba) are synthesized and grain growth behavior is investigated for different temperatures and times. Average normal grain sizes of individual specimens, which are heat-treated at 1,125 oC for 10 h, are 6.9, 2.8, and 1.6 m for M = Ca, Sr, and Ba, respectively. Depending on M, the distortion of NKN structure can be altered. XRD results show that (NKN-CaCuN: shrunken orthorhombic; NKN-SrCuN: orthorhombic; NKN-BaCuN: cubic). For the sample heat-treated at 1,125 oC for 10 h, the maximum grain sizes of individual specimens are measured as 40, 5, and 4,000 m for M = Ca, Sr, and Ba, respectively. This abnormal grain size is related to the partial melting temperature (NKN-CaCuN: 960 oC; NKN-SrCuN: 971 oC; NKN-BaCuN: 945 oC).

Tin oxide (SnO2) nanocrystals are synthesized by a thermal evaporation method using a mixture of SnO2 and Mg powders. The synthesis process is performed in air at atmospheric pressure, which makes the process very simple. Nanocrystals with a belt shape start to form at 900 oC lower than the melting point of SnO2. As the synthesis temperature increases to 1,100 oC, the quantity of nanocrystals increases. The size of the nanocrystals did not change with increasing temperature. When SnO2 powder without Mg powder is used as the source material, no nanocrystals are synthesized even at 1,100 oC, indicating that Mg plays an important role in the formation of the SnO2 nanocrystals at temperatures as low as 900 oC. X-ray diffraction analysis shows that the SnO2 nanocrystals have a rutile crystal structure. The belt-shaped SnO2 nanocrystals have a width of 300~800 nm, a thickness of 50 nm, and a length of several tens of micrometers. A strong blue emission peak centered at 410 nm is observed in the cathodoluminescence spectra of the belt-shaped SnO2 nanocrystals.