• 제목/요약/키워드: $R^2$ value

검색결과 4,663건 처리시간 0.035초

Influence of Public R&D Information Service Image on the Value and Satisfaction of Users

  • Lee, Sun Young;Suh, Sanghyuk
    • Asian Journal of Innovation and Policy
    • /
    • 제6권2호
    • /
    • pp.192-205
    • /
    • 2017
  • The aim of this study is to investigate the relative impact of the image of information service on customer's perceived value and satisfaction of R&D information. It also seeks to assess the moderating effect of service users' skills on the value of the service image on the customer. For this purpose, a field study was conducted on users of a public R&D information service called NTIS (National Technology Information Service) in Korea. The findings show that the information service image has a significant impact on customers' perceived value and satisfaction. In addition, customers' perceived value is found to be an important indicator in strengthening customer satisfaction. Findings also reveal that individual personal computer skills moderate the relationship between service image and information value. Further research is needed to strengthen the independent variable in view of the increasing pressure to improve public service quality and customer management.

승용차용 SPC 3 EN 킬드 강판의 등 2축 인장 가공성에 관한 연구 (A Study on the Equi-Biaxial Tensile Workability for the SPC 3 EN Automobile Killed Steel Sheets)

  • 김동원;서대교;김형종
    • 대한기계학회논문집
    • /
    • 제10권5호
    • /
    • pp.645-652
    • /
    • 1986
  • 본 연구는 이상의 연구결과들을 비교한 결과, Hill에 의하여 최근에 제안된 새 항복조건식에 의한 해석방법을 종합 검토함으로써, 실험결과와 이론적 해석결과 와의 합리적인 접근을 얻을 수 있다고 예상하여 수행되었다. 더 나아가 Pearce가 그의 연구 결과에 대한 고찰에서, 아마도 R 값(Lankford값)이 변형도중에 계속 일정 하게 유지되지 않을 것이며, 그것이 실험결과가 이론적 해석결과와 일치하지 않는 한 가지 원인이 될 수 있다고 언급한 사실을 고려하고, 최근 R 값에 대한 연구에서 R 값 이 변형률의 크기에 의존된다는 사실을 감안하여 R 값을 실제로 측정하였으며, 그 결 과를 등 2축인장에서의 응력-변형률선도를 해석하는데 적용하였다.

수종 임플랜트의 표면 거칠기와 초기안정성에 관한 연구 (A Study on the Surface Roughness and Initial Stability of Various Dental Implants)

  • 조동훈;임주환
    • 구강회복응용과학지
    • /
    • 제16권3호
    • /
    • pp.197-210
    • /
    • 2000
  • Surface roughness is one of implant surface topography and it's found that surface roughness characterizations, such as surface energy, oxide layer thickness and its chemical composition, are closely correlated if the roughness is changed. Several studies showed the importance of analyzing surface structure so the surface structure of thread implant was analyzed to measure the implant quality exactly. In this study, surface roughness of 4 implants - MK $II^{(R)}$(Nobel Biocare), $RBM^{(R)}$(Life-Core, USA), $Osseotite^{(R)}$(3i, USA), $TPS^{(R)}$(Life-Core, USA) - were measured using $Accura^{(R)}$ and 40 implants were installed into 4 sets of ten bovine ribs based on the parameters from the measurements. From this test, the following conclusions for the initial stability were drawn by measuring and comparing RFA, Periotest Value (PTV), Removal Torgue Value (RTV). 1. $R_a$ value in surface roughness measurement was increasing by the order of $MKII^{(R)}$, $Osseotite^{(R)}$, $RBM^{(R)}$, $TPS^{(R)}$ and $R_q$ value was the same order. 2. $R_q$ value in each section was observed to increase by the order of $MKII^{(R)}$, $Osseotite^{(R)}$, $RBM^{(R)}$, $TPS^{(R)}$ in top and $MKII^{(R)}$, $RBM^{(R)}$, $Osseotite^{(R)}$, $TPS^{(R)}$ in mid-section but the value of $MKII^{(R)}$ bottom was the lowest, followed by $Osseotite^{(R)}$, $RBM^{(R)}$ and $TPS^{(R)}$. 3. RFA increased by the order of $RBM^{(R)}$(7042Hz), $MKII^{(R)}$(7047Hz), $Osseotite^{(R)}$(7076Hz), $TPS^{(R)}$(7168Hz) and there was no significance between each group. 4. PTV was increasing by the order of $MKII^{(R)}$(-1.62), $TPS^{(R)}$(-1.92), $Osseotite^{(R)}$ & $RBM^{(R)}$(-2.08) and there was no significance, either. 5. Removal torque in RTV measurement showed the increasing order of $MKII^{(R)}(5.31kgf{\cdot}cm)$, $Oeeotite^{(R)}(5.71kgf{\cdot}cm)$, $TPS^{(R)}(5.92kgf{\cdot}cm)$ and $RBM^{(R)}(7.24kgf{\cdot}cm)$ and there was no significance among groups. Above observations explains that surface roughness does not make any impact on the initial stability of implants installation.

  • PDF

연구개발투자와 기업가치: 소유 및 지배구조의 조절효과를 중심으로 (R&D Investment and Firm Value: Focusing on the Moderating Effect of Corporate Governance and Ownership Structure)

  • 설원식
    • 산업융합연구
    • /
    • 제19권5호
    • /
    • pp.13-19
    • /
    • 2021
  • 본 연구에서는 ESG의 G(Governance) 구성요소인 기업의 소유·지배구조가 연구개발투자와 기업가치간 관련성에 유의미한 조절효과를 가지는가를 검증하였다. 2013~2020년 동안 KOSPI 시장에 상장된 405개 제조기업 총 2,825개의 표본을 대상으로 패널분석을 수행한 결과, 연구개발투자는 기업가치에 부정적인 영향을 미치며, 또한 이들 관계는 기업의 소유·지배구조 특성에 따라 조절됨을 발견하였다. 소유경영자에 비해 상대적으로 경영에 대한 전문지식 수준이 높은 전문경영자가 연구개발투자를 주도할 때, 연구개발투자가 기업가치에 미치는 부정적인 영향이 완화됨을 확인하였다. 또한, 외부 주요주주의 지분율이 높을수록 연구개발투자가 기업가치에 미치는 부정적 영향을 감소시켰는데, 이는 외부 주요주주의 힘이 강할수록 경영자를 효과적으로 감시할 수 있고 경영자에게 정보 공개를 요구하여 기업 내외부 주주간 정보비대칭성이 완화되기 때문으로 해석된다. 연구결과는 ESG의 요소들이 기업가치에 직접적인 영향을 미칠 뿐 아니라 기업가치에 대한 조절효과를 가질 수 있음을 시사한다.

$xPb(R_{1/2}Ta_{1/2})O_3-(1-x)Pb(Zr_{0.52}Ti_{0.48})O_3$(R=Al, Y) 세라믹스의 전기적 특성에 관한 연구 (A Study on the Electrical Properties of $xPb(R_{1/2}Ta_{1/2})O_3-(1-x)Pb(Zr_{0.52}Ti_{0.48})O_3$(R=Al,Y) Ceramics)

  • 강도원;박태모
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
    • /
    • pp.157-160
    • /
    • 2001
  • We have investigated the Dielectric and Piezoelectric properties of $xPb(R_{1/2}Ta_{1/2})O_3-(1-x)Pb(Zr_{0.52}Ti_{0.48})O_3$ (R=Al,Y) solid solutions in which R ions are substituted for Al and Y ions. The maximum value of electromechanical coupling factor kp of 55% and 51% were obtained at the composition of 5mol% PAT and 5mol% PYT. However mechanical quality factor$(Q_m)$ had a minimum value of 44 and 69 at the composition of 5mol% PAT and 5mol% PYT. Also, the maximum value of piezoelectctric constant of $d_{33}(329[pC/N])$ and $d_{33}(310[pC/N])$ were obtained at the composition of 5mol% PAT and 5mol% PYT.

  • PDF

Reactions of 4-Nitrophenyl 2-Thiophenecarboxylates with R2NH/R2NH2+ in 20 mol % DMSO (aq). Effects of 5-Thienyl Substituent and Base Strength

  • Pyun, Sang Yong;Cho, Bong Rae
    • Bulletin of the Korean Chemical Society
    • /
    • 제34권7호
    • /
    • pp.2036-2040
    • /
    • 2013
  • Reactions of 4-nitrophenyl 2-thiophenecarboxylate (1a-e) with $R_2NH/R_2NH{_2}^+$ in 20 mol % DMSO (aq) have been studied kinetically. The $2^{nd}$ order kinetics, ${\beta}_{nuc}$ = 0.88-0.98, and linear Hammett and Yukawa-Tsuno plots observed for these reactions indicate an addition-elimination mechanism in which the $2^{nd}$ step is rate limiting. The ${\beta}_{nuc}$ value increased with a stronger electron-withdrawing 5-thienyl substituent, the Hammett plots are linear except for X = MeO, and Yukawa-Tsuno plots are linear with ${\rho}$ = 0.79-1.32 and r = 0.28-0.93, respectively. The ${\rho}$ value increased and r value decreased with a stronger nucleophile, indicating an increase in the electron density at the C=O bond and a decrease in the resonance demand. These results have been interpreted with enhanced N-C bond formation in the transition state with the reactivity increase.

경영자 특성에 따른 R&D 투자와 기업가치 관련성: 벤처기업을 중심으로 (Relationship between R&D Investment and Firm Value by Characteristics of CEO: Focused on Venture Business)

  • 김이진;김정은;전성일
    • 중소기업연구
    • /
    • 제41권1호
    • /
    • pp.75-96
    • /
    • 2019
  • 본 연구의 목적은 기업 내 최고의사결정권한을 가진 CEO의 특성이 R&D 투자 결정과 기업가치에 어떠한 영향을 미치는지를 검증하는 것이다. 구체적으로 CEO의 특성을 나이, 학력, 전공일치, 재직기간으로 측정하여, 이러한 특성이 연구개발투자 및 기업가치에 미치는 영향을 실증적으로 분석하였다. 2005년부터 2014년까지 코스닥 시장에 상장된 벤처기업을 대상으로 실증 분석한 결과는 다음과 같다. 첫째, CEO의 나이는 적을수록 R&D 투자를 보다 많이 하는 것으로 나타났으며, 나이가 적은 CEO의 R&D 투자는 기업가치와 유의한 양(+)의 상관성을 보이는 것으로 나타났다. 둘째, CEO의 학력은 높을수록 R&D 투자를 보다 많이 하는 것으로 나타났고, 교육수준이 높은 CEO의 R&D 투자는 주가와 유의한 양(+)의 관련성을 보였다. 셋째, CEO의 전공과 업종이 일치할수록 R&D 투자는 보다 많이 하는 것으로 나타났으며, CEO의 전공일치도가 높은 기업의 R&D 투자와 주가와의 가치관련성은 보다 높은 것으로 나타났다. 마지막으로 CEO의 재직기간은 길수록 R&D 투자에 보다 적극적인 태도를 보였으나, 재직기간이 긴 CEO의 R&D 투자는 기업가치와 유의한 음(-)의 관련성을 보였다. 이와 같은 실증 분석을 통해 벤처기업의 R&D 투자와 기업가치관련성은 CEO의 특성이 반영된다는 사실을 확인할 수 있었다. 본 연구는 CEO의 인구통계학적 특성을 반영한 R&D 투자가 자본시장에서 어떻게 평가 받고 있는지를 실증적으로 검증하였다는 점에 의의가 있다.

마른 오징어의 품질평가 및 보존기간 (Quality Evaluation and Shelf-life of Dried Squid)

  • 유병진;이강호
    • 한국수산과학회지
    • /
    • 제21권3호
    • /
    • pp.169-176
    • /
    • 1988
  • In order to obtain the objective indices which can assess the quality and the shelf-life of dried squid, nonenzymatic browning, carbonyl value, trimethyl amine (TMA) and trimethyl amine oxide (TMAO) decrease and panel test were determined in dried squid at various water activity levels. When the data of nonenzymatic browning fit a zero order equation, $r^2$ value were more than 0.92 except aw 0.52 for 0.8241. Through variance analysis for the data of browning extent and TMAO decrease, the confidence limits of regression equation were $99\%$ and their limit values of shelf-life were shown 0.45390 O. D./g. solid and 190.322 g/g respectively. In case of TMAO, $r^2$ value was calculated more than 0.95. Linear regression equation for the correlation between browning data and average panel score was Y=0.6138-0.053X and its $r^2$ value was 0.9285. Also in TMAO decrease, the equation was InY=2.0314+0.08269x and $r^2$ value was 0.7854. The shelf-life, evaluated by nonenzymatic browning, TMAO decrease and panel test, was 110-170 days at aw 0.45-0.76 except aw 0.15.

  • PDF

ON THE γ-TH HYPER-KLOOSTERMAN SUMS AND A PROBLEM OF D. H. LEHMER

  • Tianping, Zhang;Xifeng, Xue
    • 대한수학회지
    • /
    • 제46권4호
    • /
    • pp.733-746
    • /
    • 2009
  • For any integer k $\geq$ 2, let P(c, k + 1;q) be the number of all k+1-tuples with positive integer coordinates ($a_1,a_2,...,a_{k+1}$) such that $1{\leq}a_i{\leq}q$, ($a_i,q$) = 1, $a_1a_2...a_{k+1}{\equiv}$ c (mod q) and 2 $\nmid$ ($a_1+a_2+...+a_{k+1}$), and E(c, k+1; q) = P(c, k+1;q) - $\frac{{\phi}^k(q)}{2}$. The main purpose of this paper is using the properties of Gauss sums, primitive characters and the mean value theorems of Dirichlet L-functions to study the hybrid mean value of the r-th hyper-Kloosterman sums Kl(h,k+1,r;q) and E(c,k+1;q), and give an interesting mean value formula.

소방대원의 외상후 스트레스 실태 (Posttraumatic Stress in Fire fighters)

  • 고봉연
    • 한국응급구조학회지
    • /
    • 제12권3호
    • /
    • pp.5-15
    • /
    • 2008
  • Purpose : This study is a descriptive research to provide basic factors of posttraumatic stress in Firefighters. This study was carried out to develop the effective program for the fire fighters to cope with the posttraumatic stress following the disasters. Methods : The questionnaires were collected among fire fighters who serviced in K and I community from April 1 to June 30 in 2008. Total 304 questionnaires were analyzed by SPSS WIN program for descriptive statistics, Pearson's correlation coefficient and t-test. Results : 1. 48.0% of 300 fire fighters were at the age of 31-40, and 42.3% were under 30. 2. Work burden had a significant difference of 2.30 in low-risk group, 2.60 in high-risk group(t-value=-3.85, p=0.00). However, life event had no significant difference 0.79 event in low-risk group, 1.41 event in high-risk group(t-value=-2.27, p=0.24). 3. Concerning posttraumatic stress factors, there was positive correlation between mobilization impact level r=0.38(P<0.01), work burden r=0.38(p<0.01), and life event r=0.27(p<0.01). 4. According to the Symptom Check List-Revised(SCL-90-R), somatization had a significant differences(t-value=5.46, p=0.00), obsessive-compulsive(t-value=7.16, p=0.00), interpersonal sensitivity(t-value=6.15, p=0.00), depression(t-value=6.62, p=0.00), anxiety (t-value=7.33, p=0.00), hostility(t-value=5.94, p=0.00), phobia anxiety(t-value=6.85, p=0.00), paranoid ideation(t-value=5.55, p=0.00), psychotism(t-value=6.52, p=0.00) in low-risk and high-risk group. Conclusion : As a consequence, mobilization impact, work burden, and life event were the influential factors on posttraumatic stress. Also, high-risk group revealed significantly higher score on all 9 scales. The information obtained from surveys made recommendation to develop the intervention of stress management to control mobilization impact and posttraumatic stress.

  • PDF