• 대한기계학회논문집A
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• 제25권5호
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• pp.866-873
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• 2001

The governing partial differential equations of a helical spring with a circular section were derived from Frenet formulas and Timoshenko beam theory. These were solved to give the dispersion relationship between wave number and frequency along with wave form. Wave motions of helical springs are categorized by 4 regimes. In the first regime, the lower frequency area, the torsional and extensional waves of the spring are predominant and two waves are composite wave motions involving lateral motion of the coils and rotation of the coils about a horizontal axis. All waves are propagating in the second regime. The wave of the extensional motion of the spring and one wave of transverse motion of a wire change from travelling waves to near field waves in the third regime. Both waves excited by both axial and transverse motion are predominant in the fourth regime.

• 한국환경과학회지
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• 제12권10호
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• pp.1101-1108
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• 2003

We studied the relationship between a civil affair occurrence of bad smell and meteorological conditions around Seongseo district for recent 2 years. The results were as follows; (1) The civil affair occurrence days of bad smell were concentrated from May to August. (2) Daily mean temperatures were mostly 20∼28$^{\circ}C$ and daily mean relative humidities were 60∼80%. (3) Wind speeds were mostly less than 2㎧(75%), and wind directions were southerly winds(50%). It was hardly occurred for relatively well-ventilated conditions in cases of wind speeds 2㎧ over. And the Lagrangian particle dispersion model were used to figure out the transport route in a civil affair occurrence days of bad smell. It was found that the south-western winds transported the bad smelling materials from Jungni-dong(the place of source) to the housing complex located along a piedmont district.

• Asia Marketing Journal
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• 제15권3호
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• pp.53-77
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• 2013

As advertising and promotions are categorized as operating expenses, managers tend to reduce marketing budget to improve their short term profitability. Gauging the value and accountability of marketing spending is therefore considered as a major research priority in marketing. To respond this call, recent studies have documented that financial market reacts positively to a firm's marketing activity or marketing related outcomes such as brand equity and customer satisfaction. However, prior studies focus on the relation of marketing variable and financial market variables. This study suggests a channel about how marketing activity increases firm valuation. Specifically, we propose that a firm's marketing activity increases the level of the firm's product market information and thereby the dispersion in financial analysts' earnings forecasts decreases. With less uncertainty about the firm's future prospect, the firm's managers and shareholders have less information asymmetry, which reduces the firm's cost of capital and thereby increases the valuation of the firm. To our knowledge, this is the first paper to examine how informational benefits can mediate the effect of marketing activity on firm value. To test whether marketing activity contributes to increase in firm value by mitigating information asymmetry, this study employs a longitudinal data which contains 12,824 firm-year observations with 2,337 distinct firms from 1981 to 2006. Firm value is measured by Tobin's Q and one-year-ahead buy-and-hold abnormal return (BHAR). Following prior literature, dispersion in analysts' earnings forecasts is used as a proxy for the information gap between management and shareholders. For model specification, to identify mediating effect, the three-step regression approach is adopted. All models are estimated using Markov chain Monte Carlo (MCMC) methods to test the statistical significance of the mediating effect. The analysis shows that marketing intensity has a significant negative relationship with dispersion in analysts' earnings forecasts. After including the mediator variable about analyst dispersion, the effect of marketing intensity on firm value drops from 1.199 (p < .01) to 1.130 (p < .01) in Tobin's Q model and the same effect drops from .192 (p < .01) to .188 (p < .01) in BHAR model. The results suggest that analysts' forecast dispersion partially accounts for the positive effect of marketing on firm valuation. Additionally, the same analysis was conducted with an alternative dependent variable (forecast accuracy) and a marketing metric (advertising intensity). The analysis supports the robustness of the main results. In sum, the results provide empirical evidence that marketing activity can increase shareholder value by mitigating problem of information asymmetry in the capital market. The findings have important implications for managers. First, managers should be cognizant of the role of marketing activity in providing information to the financial market as well as to the consumer market. Thus, managers should take into account investors' reaction when they design marketing communication messages for reducing the cost of capital. Second, this study shows a channel on how marketing creates shareholder value and highlights the accountability of marketing. In addition to the direct impact of marketing on firm value, an indirect channel by reducing information asymmetry should be considered. Potentially, marketing managers can justify their spending from the perspective of increasing long-term shareholder value.

• 농업과학연구
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• 제41권4호
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• pp.315-319
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• 2014

Mean densities of two-spotted spider mite (TSM), Tetranichus urticae Koch adults from January to April in 2014 to investigate the occurrence and dispersion pattern of T. urticae on purpose of developing a monitoring method in the strawberry PVC house. Difference of density of T. urticae adult on middle and both side of leaf wasn't significantly. Density of T. urticae in investigation at different furrows and investigating points was the highest at the right and left sides of a furrow in strawberry PVC house. In results of comparing the dispersion incides of Taylor's power law (TPL) with Iwao's patchiness regression (IPR), TPL described better mean-relationship for the dispersion indieces compared to IPR. Slopes and intercepts of TPL from leaf samples did not differ among surveyed regions. Also, Distribution of T. urticae in a strawberry PVC house was the gravitation of the distribution because b and ${\beta}$ values of TPL and IPR was bigger than 1.

• 공업화학
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• 제2권3호
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• pp.209-215
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• 1991

n-헥산과 40 wt % p-TSA 수용액으로 이루어진 비혼화성 액상계에서 교반에 의한 유기상의 분산을 해석하였다. 사용된 교반기는 blade의 형태가 flat와 금망으로 된 4가지 형태의 6-bladed turbine 교반기를 사용하였다. 실험결과, 동일한 교반속도에서 유기상의 분산정도는 blade의 형태가 flat, 60 mesh, 40 mesh, 20 mesh의 순서로 감소하였고 계면활성제인 TBA의 농도가 증가할수록, 그리고 유기상의 부피비가 작을수록 유기상은 잘 분산되었다. 또한 완전분산에 필요한 최소교반속도는 flat, 60 mesh, 40 mesh, 20 mesh의 순서로 증가하였으나 최소소요동력은 거의 동일하였다. 이때 Power number와 Reynolds number와의 관계는 $N_p=a\;N_{Re}{^b}$ 이었으며 교반기의 형태에 따른 상수 a와 혼합계의 종류에 따른 상수 b의 값은 각각 2200~4100, -0.69~-0.63 범위이었다.

• 한국응용곤충학회지
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• 제40권2호
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• pp.105-109
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• 2001

귤응애의 예찰방법을 개발하기 위하여 제주지역의 온주밀감원에서 귤응애 분산형태에 대해 2개년(1999~2000년)에 걸쳐 잎 표본에 대하여 각 조사일에 평균밀도를 조사하였다. Taylor's power law와 Iwao's patchiness regression을 이용하여 분산지수를 비교하였으며, 잎 표본 조사에서는 일반적으로 Taylor's power law가 Iwao's patchiness regression보다 평균-분산 관계를 더 잘 나타내었다. Taylor's power law의 기울기와 절편은 조사한 포장 간에 차이가 없었으며, 여기에서 얻어진 상수값을 이용하여 잎 표본 조사에 의한 귤응애 약 .성충에 대한 고정정확도수준에서의 표본조사법을 개발하였다. 이 조사법에 대해 resampling 기법을 이용하여 독립된 4개의 조사자료를 이용하여 분석한 결과 실질 고정정확도(D)값이 요구되는 D값보다 항상 낮았으며, 나무당 귤응애 밀도가 8마리 이상에서 필요한 조사 나무수는 18주보다 작았다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.2071-2077
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• 2013

Esophageal cancer is a mjaor health problems in many parts of the world. A geographical information system (GIS) allows investigation of the geographical distribution of diseases. The purpose of the present study was to explore the relationship between esophageal cancer and effective climatic factors using GIS. The dispersion distribution and the relationship between environmental factors effective on cancer were measured using Arc GIS. The highest degree of spread was in Germi town and the least was in Ardabil city. There was a significant relationship between effective environmental factors and esophageal cancer in Ardabil province. The results indicated that environmental factors probably are influential in determining the incidence of esophageal cancer. Also, these results can be considered as a window to future comprehensive research on esophageal cancer and related risk factors.

• 지구물리와물리탐사
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• 제17권1호
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• pp.11-20
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• 2014

원주시 저고도 지역에서의 천부 횡파속도($v_s$) 및 부지특성을 파악하기 위해 2013년 2월부터 2013년 9월 사이의 20일간 4.5 Hz 수직 지오폰 12 ~ 24개를 이용하여 원주시계 내의 78 지점에서 레일리파를 기록하였다. 레일리파 분산곡선은 확장된 공간자기상관함수법으로 구하였고, $v_s$를 구하기 위하여 감소최소자승법으로 역산하였다. 이들 1-D 모델로부터 구한 풍화암질 기반암의 깊이($D_b$), 기반암의 횡파속도($v_s^b$), 토양층의 평균 횡파속도($\bar{v}_s^s$), 30 m까지 평균 횡파속도($v_s30$)는 95% 신뢰구간에서 각각 $16.3{\pm}0.7m$, $576{\pm}8m/s$, $290{\pm}7m/s$, $418{\pm}13m/s$로 산출되었다. $v_s30$의 적절한 지시자를 결정하기 위해서 $v_s30$과 지표면 경사도(r = 0.46) 및 고도(r = 0.43)와의 상관계수를 계산하였고, 개별적으로 평가한 $v_s30$과의 상관성을 종합하여 지표면 경사도, 고도, 암상의 가중치를 각각 0.45, 0.45, 0.1으로 하는 선형 경험식을 제시하였다. 그러나 이 경험식과 역산으로 구한 $v_s30$의 상관성이 미약하여(r = 0.50), 적용시에는 상대적으로 큰 오차범위를 고려해야 할 것이다.

• 한국ITS학회 논문지
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• 제12권4호
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• pp.22-32
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• 2013

고속도로 이용차량중 통행료 전자지불장치인 하이패스를 장착한 차량의 비율이 급속도로 증가하고 있는 상황에서, 요금소 하이패스 차로 배치의 최적화는 교통제어와 운영측면에서 매우 중요하다. 본 연구에서는 영업소별 물리적 기하구조 형태와 교통 특성을 고려하여 현재의 하이패스차로 설치 위치의 적정성을 분석하였다. 이를 위해 하이패스 차로별로 차량이 균등하게 배분되어 이용하는가를 측정하기 위해 "하이패스차량 교통분산율"이라는 새로운 평가지표를 개발하였다. 또한 교통분산율에 영향을 주는 변수들을 도출하여 이러한 변수들과 교통분산율과의 관계를 로지스틱회귀모형을 이용하여 추정하였다. 모형추정결과에 따르면 하이패스 교통량, 광장부 길이, 진입연결로와의 거리, 진출연결로와의 거리, 중앙 배치비율, 우측배치비율 등의 변수들이 교통분산율에 영향을 주는 것으로 파악되었으며, 이중에서 하이패스 차로배치 위치 변수인 중앙 배치비율, 우측 배치비율을 조정함으로서 교통분산율을 개선할 수 있는 것으로 밝혀졌다. 본 연구를 통해 하이패스차로 배치의 적정성을 판단할 수 있는 교통분산율을 계량화할 수 있게 되어 하이패스차로 위치 선정과 운영방식을 최적화할 수 있을 것으로 기대된다.

• 마케팅과학연구
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• 제19권2호
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• pp.40-52
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• 2009

Franchising is one of the fastest growing types of business. It is already popular and well-known in the U.S., and has been growing in many other countries including Korea. Furthermore, many Korean franchising companies have expanded their business overseas actively. According to the data by the Ministry of Industry and Resource, 82 companies out of a sample of 500 franchising companies are already operating in many foreign countries and 48% of them have started their foreign business since 2006. This clearly indicates the fast growing current trend of foreign operation by Korean franchising companies. In spite of the fast growing trend of foreign expansion in the industry, academic research on internationalization of franchising companies is extremely difficult to find. Accordingly, academic research on the issue is necessary and urgent in Korea. Among the various research questions on internationalization of franchising business, this study intends to investigate the difference in organizational factors between the franchising companies doing foreign operation and those doing business only domestically. More specifically, this research has the following purposes. First, considering the lack of theoretical basis of previous studies, resource-based theory and agency theory are employed as the theoretical bases. Second, this study explains the difference in internationalization based on organizational factors such as company size, history and growth rate. Third, the five hypotheses regarding the difference in organizational factors are presented and tested empirically, which is the first attempt in the area of this topic. Finally, the study attempts to clarify the conflicting implications among theories regarding some organizational factos such as growth rate. As the theoretical background, resource-based theory and agency theory are discussed. According to resource-based theory, a firm can grow continuously when it has competence and resource, and also the ability to develop them. The competence and resource can include capital, human resource, management skill, market information, ability to manage risk, etc. Meanwhile, agency theory views the relationship between franchisor and franchisee as an agency relationship. In agency theory, bonding capability and monitoring capability are the two key factors which promote internationalization of franchising companies. Based on the two theories, a conceptual model is designed. The model consists of two groups of variables. One is organizational factors including size, history, growth rate, price bonding and geographic dispersion. The other is whether a franchising company is operating overseas or not. We developed the following five research hypotheses basically describing the relationship between organizational factors and internationalization of franchising companies. H1: The size of franchising companies operating overseas is larger than that of franchising companies operating domestically. H2: The history of franchising companies operating overseas is longer than that of franchising companies operating domestically. H3: The growth rate of franchising companies operating overseas is higher than that of franchising companies operating domestically. H4: The price bonding of franchising companies operating overseas is higher than that of franchising companies operating domestically. H5: The geographic dispersion of franchising companies operating overseas is wider than that of franchising companies operating domestically. Data for the analyses are obtained from 2005 Korea Franchise Survey data co-generated by Ministry of Industry and Resource, GS1 Korea, and Korea Franchise Association. Out of 2,804 population companies, 2,489 companies are excluded for various reasons and 315 companies are selected as the final sample. Prior to hypotheses tests, validity and reliability of the measures of size, history, growth rate and price bonding are examined for further analyses. Geographic dispersion is not validated since it is measured using nominal data. A series of independent sample T-tests is used to find out whether there exists any significant difference between the companies internationalized and those operating only domestically for each organizational factor. Among the five factors, size and geographic dispersion show significant difference, growth rate and price bonding do not reveal any difference and, finally, history factor shows conflicting results in the difference depending on how to measure it.