• 제목/요약/키워드: two sample t-test

검색결과 588건 처리시간 0.027초

다양한 석고제품으로 제작한 석고 모형의 정확성의 평가: 3차원 이미지의 컴퓨터 지원 분석 (Three-dimensional evaluation of stone models made of various gypsum products)

  • 김욱태
    • 대한치과기공학회지
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    • 제42권4호
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    • pp.321-325
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    • 2020
  • Purpose: This study is to evaluate the accuracy of gypsum replica models made from various gypsum products. Methods: One main model was made of stainless steel by CNC milling process. Molds were formed from the main model, and the gypsum replica models were made using 8 types of type IV gypsum, 10 pieces each. The main model was digitized by a contact scanner (Incise; Renishaw) and the gypsum replicas were digitized by an optical scanner (E4; 3Shape A/S). The difference between the main model and the gypsum replicas were measured by inspection software (3D Systems). One-way ANOVA was performed to evaluate the statistical significance of differences between groups. In addition, the independent sample T test was performed to determine the difference between the conventional and scannable stone group (n=10, α=0.05). Results: The root mean square of the stone models were 7.24 ㎛ to 10.78 ㎛, and statistical significance was found between the two groups (SR, FR) and the other 6 groups (IS, SG, CA, CS, ER, EBG) (p<0.05). The accuracy of the gypsum replicas was 9.04 ㎛ and 7.62 ㎛ in the conventional and scannable stone group, respectively. There was statistical significance between the two groups (p<0.01). Conclusion: In the limited results of this study, the product with low setting expansion and the scannable showed high accuracy. Therefore, in order to obtain a stable and accurate scan model, it is more effective in terms of accuracy to use a scannable stone with a low setting expansion.

어촌특화 역량강화사업의 성과 및 주민의식 변화분석 (Analysis of the Performance and Change of Resident Consciousness of the Fishing Village Specialization Capacity Enhancement Project through Surveys - Focusing on the Comparative Analysis of Consciousness of Inland Water and Coastal Residents -)

  • 양민호;김기성;고진영
    • 한국농공학회논문집
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    • 제63권2호
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    • pp.19-31
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    • 2021
  • The Ministry of Maritime Affairs and Fisheries has been promoting the 'Fishing Village Specialization Capacity Enhancement Project' to pursue sustainable development of villages such as income generation by using local tangible and intangible resources led by local residents at the village level since 2013. For the fishing village-Specialization capacity enhancement project, six training sessions (mainly in the village unit) are selected by the public offering method, and the project (income generating business, village development project, etc.) is developed for the selected village residents. It has a process of establishing a village project plan (a preliminary plan for village development or a sixth preliminary industrialization plan) based on the training of experts 5 times, practice or excursion 1 time). In this study, four villages in Gangwon-do fishing villages (two coastal villages and two inland water villages) were surveyed on the perception and satisfaction of fishing village development projects before and after training. The survey analysis was conducted by dividing the analysis of resident capacity and satisfaction into personal, interpersonal, and social dimensions. The survey was conducted by distributing a survey before and after training, and a 1:1 survey was conducted according to the residents' cognitive status. Based on the survey, factor analysis, reliability analysis, and analysis using the corresponding sample t-test showed an increase of 0.02 for Yangyang Mulchi fishing village, 0.11 for Samcheok Jangho fishing village, and 0.36 for Hongcheon River fishing industry, but Yanggu Jinmok fishing industry was -0.29, unlike other regions. As a result of this analysis, it has been empirically proven that provision of training projects through resident participation is a very important factor for the success of the fishing village project. Therefore, rather than fostering local leaders, training and community activities to strengthen personal capacities of residents participating in the project, it is necessary to operate the software business with a focus.

전방 점프 착지 시 만성 발목 불안정성이 자세 조절에 미치는 영향 (The Effects of Chronic Ankle Instability on Postural Control during Forward Jump Landing)

  • Kim, Kew-wan;Jeon, Kyoungkyu;Park, Seokwoo;Ahn, Seji
    • 한국운동역학회지
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    • 제32권1호
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    • pp.9-16
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    • 2022
  • Objective: The purpose of this study was to investigate how the chronic ankle instability affects postural control during forward jump landing. Method: 20 women with chronic ankle instability (age: 21.7 ± 1.6 yrs, height: 162.1 ± 3.7 cm, weight: 52.2 ± 5.8 kg) and 20 healthy adult women (age: 21.8 ± 1.6 yrs, height: 161.9 ± 4.4 cm, weight: 52.9 ± 7.2 kg) participated in this study. For the forward jump participants were instructed to stand on two legs at a distance of 40% of their body height from the center of force plate. Participants were jump forward over a 15 cm hurdle to the force plate and land on their non-dominant or affected leg. Kinetic and kinematic data were obtained using 8 motion capture cameras and 1 force plates and joint angle, vertical ground reaction force and center of pressure. All statistical analyses were using SPSS 25.0 program. The differences in variables between the two groups were compared through an independent sample t-test, and the significance level was to p < .05. Results: In the hip and knee joint angle, the CAI group showed a smaller flexion angle than the control group, and the knee joint valgus angle was significantly larger. In the case of ankle joint, the CAI group showed a large inversion angle at all events. In the kinetic variables, the vGRF was significantly greater in the CAI group than control group at IC and mGRF. In COP Y, the CAI group showed a lateral shifted center of pressure. Conclusion: Our results indicated that chronic ankle instability decreases the flexion angle of the hip and knee joint, increases the valgus angle of the knee joint, and increases the inversion angle of the ankle joint during landing. In addition, an increase in the maximum vertical ground reaction force and a lateral shifted center of pressure were observed. This suggests that chronic ankle instability increases the risk of non-contact knee injury as well as the risk of lateral ankle sprain during forward jump landing.

Assessment of pharyngeal airway in Korean adolescents according to skeletal pattern, sex, and cervical vertebral maturation: A cross-sectional CBCT study

  • Elagib, Tassneem;Kyung, Hee-Moon;Hung, Bui Quang;Hong, Mihee
    • 대한치과교정학회지
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    • 제52권5호
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    • pp.345-353
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    • 2022
  • Objective: To investigate airway volumes using cone-beam computed tomography (CBCT) by skeletal patterns, sex, and cervical vertebral maturation (CVM) stages in Korean adolescents. Methods: The sample consisted of pretreatment CBCT and cephalograms of 95 adolescents (aged 12-19) obtained out of 1,611 patients examined for orthodontic treatment from 2018 to 2020 in Kyungpook National University Dental Hospital. The samples were classified into two sex groups; three skeletal pattern groups, four chronological age groups and four CVM stages. Nasopharyngeal volumes (NPV), oropharyngeal volumes (OPV), total pharyngeal airway volume (TAV) and minimum cross-sectional area (MCA) measurements were taken from the CBCT. Multiple linear regression analyses to find out which one of the independent variables are good predictors for airway variables. Significant factors were analyzed by two-way multivariate analysis of variance (MANOVA) then multiple comparisons were analyzed using a t-test, and Fisher least significant difference. Results: Age, sex, CVM, and Sella-Nasion-B point have significant influence on airway variable. Males and females showed similar patterns of change in chronological age groups 1-3; however, males had larger NPV, OPV, and MCA at CVM in group 4. According to CVM stages, males had larger OPV, TAV, and MCA at CVM stage 6 (p-value: 0.019, 0.021, 0.015, respectively) and no sex differences at CVM stages 3, 4, and 5. Conclusions: Skeletal patterns have an effect on airway volume. Sex differences were found in CVM 6.

대뇌 신경 교종 18F-FDG PET/CT 검사에서 포도당 부하 기법에 대한 고찰 (A Discussion on Glucose Loading Method in 18F-FDG PET/CTfor Cerebral Gliomas)

  • 최용훈;박민수;임한상;김재삼
    • 핵의학기술
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    • 제27권1호
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    • pp.62-65
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    • 2023
  • Purpose The purpose of this study is to determine whether the glucose loading method (GLM) is useful in the differentiation of cerebral gliomas by comparing it with fasting images. Materials and Methods The patients were 70 people diagnosed with cerebral gliomas, and the equipment was Discovery 710 (GE Healthcare, MI, USA). All patients fasted for more than 6 hours, and fasting images and GLM were performed under the same imaging conditions, and the examination interval was 1 to 14 days. GLM administered 250 ㎖ of 10% glucose solution prior to radiopharmaceutical injection. SUVmax of cerebral glioma and SUVmean of cerebral cortex were measured and then compared and analyzed by tumor-to-normal brain cortex ratio (TNR). Statistical analysis confirmed the difference between the two images with an independent-sample t-test. Results The averages of GLM and fasting TNR were 1.26 and 1.09, respectively, which were 15.6% higher in GLM. In low-grade, the difference in TNR was insignificant at 4%, but in high-grade, 23%, GLM was high. There was a statistically significant difference between the two images (P=0.008), but there was no statistically significant difference in TNR in the low grade (P=0.473), and there was a very significant difference in the high grade (P=0.005). Conclusion GLM increased TNR for cerebral gliomas. In particular, it was found that the TNR increased more in the high grade. Therefore, GLM is considered to be useful for the differentiation of high-grade gliomas.

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성별에 따른 대학생의 피자전문점 선택에 영향을 미치는 속성 평가 (Estimation of Attributes Affecting University Students to Select the Pizza Restaurant by Gender)

  • 강종헌;정인숙
    • 한국식생활문화학회지
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    • 제21권1호
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    • pp.57-64
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    • 2006
  • The purpose of this study was to measure the pizza purchasing behavioral characteristics of respondents and importances of factors affecting pizza purchase, to estimate the effects of attributes on pizza restaurant choice, and to predict probability of selecting a particular pizza restaurant. The questionnaire consisted of two parts: The paired experimental profiles, purchasing behavior and importances of factors affecting pizza purchase. This study generated profiles of 16 hypothetical pizza restaurant based on the seven attributes. The profiles comprised 16 discrete sets of variables, each of which had two levels. For this study, researcher randomly selected 150 students of university as respondents. Twenty students did not complete the survey instrument, resulting in a final sample size of 129. All estimations were carried out using frequencies, $X^2$, independent samples t-test, phreg procedure of SAS package. The results are as follows. Some purchasing behavioral characteristics and importances of factors affecting pizza purchase were significantly different by gender. Based on the estimated models developed for male student group and female student group, the Chi-square statistics were significant at p<0.001. The parameter estimate for late delivery time with male student group was highest, and the parameter estimate for price with female student group was highest. The pizza restaurant that charged \20,000, offered 100% discount on eleventh pizza, promised to deliver pizza in 40 mins, usually delivered the pizza as promised time, offered only 1 type of pizza crust, delivered warm pizza, offered the money-back guarantee was favored by each of male student group and female student group. The results from this study suggested that there was an opportunity to increase market share and profit by improving operations so that customers receive discount and money-back guarantee simultaneously, and by reducing price, delivery time.

일부 여자 중학생의 자아개념 및 스트레스와 적응행동에 관한 연구 (A Study on Self-Concept, Stress and Adaptation Beharior of Junior School Girls)

  • 노혜숙
    • 보건교육건강증진학회지
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    • 제3권1호
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    • pp.43-55
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    • 1985
  • The recent problems of adolescents are leading us to amphasize school mental health program. Therefore, for the first step of that program, this study was attempted to find out the students' daily life stress, their adaptation beharior to resolve that stress, and their self-concept which has an effect on that beharior, to analyze the relationship among those three variables, and to provide basic data which help maintain and promote students' adaptability and mental health. The subjects were 4 classes each grade, 743 students who were chosen as a sample subject among the total of 3,250 students of a junior girls' school in Seoul by stratified sampling method. The Oquestionnair surrey was done from April 1, 1985 to April 6, 1985. The instruments were (1) a part of Junghoon chois' perceptual Orientation Scale for measuring self-perception of students, (2) Rosenberg's Questionnair for measuring students' evaluation of self-esteem, (3) modified Bell's Adoptive Behavior Questionnair, and (4) the Measuring scale for stress developed by the investigator. The collected data were analyzed by using descriptive statistics, x²-test, t-test, ANOVA, and Pearsons' Correlation. The results are summarized as follows: 1. The range of mean score of self-concept, stress, and adaptation beharior is 1-5 respectively. The mean score of self concept was 3.45. The mean score of stress was 2.53, and the degree of stress was in order of the problem of study and grade marks, girl friend, appearance, and relaxation. The subjects preferred effective long-term adaptation method (Mean=2.81) to ineffective short-term adaptation method. (Mean=2.47) 2. The self-concept had the highest degree when students were 1st grade, in good health condition, taking high grade marks, both parents existing, fathers' educational level being above college, and being in high economic status. The degree of stress was significantly high when students were 3rd grade, in poor health condition, having low grade marks, being in poor economic status, and fathers' educational level being under elimentary school. In relation with adaptation method, 1st grade students used more sbort-term and long-term method, and when students had high grade marks, being in high economic status. they used more long-term adaptation behavior. 3. Two Hypotheses of this research were tested: Hypothesis 1. "The higher the students' self-concept is, the more they use long-term adaptation method." was accepted. (r=.2482, p<.01) (t=-4.99, p<.001) Hypothesis 2. "The higher the students' stress is, the more they use short-term adaptation method." was accepted. (r=.2897, p<.01) (t= -7.51, p<.001) In conclusion, a person in charge of school health can help students to adapt effectively by planning and implementing methods which highten their self-concept and lower their stress. But because the correlation among self-concept, stress and adaptation behavior was at a low level, I think that the study, which confirm the relationship of those three variables, is needed.

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병원 간호조직의 구조유형에 따른 간호조직특성과 직무만족과의 관계 (The Relationships Between The Hospital형s Organizational Pattern For Nursing, Organizational Characteristics Perceived By Nurses and Their Job Satisfaction)

  • 장정화;박성애
    • 대한간호학회지
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    • 제23권3호
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    • pp.397-416
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    • 1993
  • This study identified the relationships between the hospital’s organizational pattern for nursing, the organizational characteristics perceived by nurses and their job satisfaction. The study subjects were a convenience sample of 383 staff nurses working at 10 general hospitals with more than 300 beds in Seoul. Hospitals included in the study were classified Into five organizational patterns, where nursing was organized as an independent but lower level, attached to the medical department, attached to a department supporting medicine, and various other organizational pattern. The data were collected from July 10 to August 15, 1992. The organizational characteristics as perceived by the staff nurses were measured by Park & Yoon’s Scale (1986) and job satisfaction was measured by Slavitt’s Scale (1978). The data were analyzed by percentage distribution, Pearson’s correlation, x$^2$-test, t-test, ANOVA, and ANCOVA The summarized results are as follows : 1. The proportion of independent and attached nursing organizational patterns was 35.1% and 54.9% respectively. 2. There were differences between four general characteristics of the nurses, age, experience, position and education level, and the five structural types of nursing organization(p〈.05). 3. 1) There were no relationship between the perceived organizational characteristics and general characteristics of the nurses but there was a differ once in job satisfaction according to education level of nurses in hopitals where nursing was an independent department(T=-2.24, p〈.05). 2) There were differences in the perceived organizational characteristics according to age group and experience of nurses (F=3.26, 5.41, p〈 , 05)and in job satisfaction according to the position of nurses in the independent but lower level organizational pattern (T=2.26, p〈.05). 3) There was a difference in the perceived organizational characteristics according to age group (F=3.19, p〈 .05) and in job satisfaction according to the experience of nurses where nursing was attached to the medical department (F=3.49, p〈.05). 4) There was a difference in the perceived organizational characteristics according to nursing unit (F=3.19, p〈 .05), but none between job satis-faction and general characteristics of nurses where nursing was attached to a departiment supporting medicine. 5) There were no relationships between the perceived organizational characteristics and job sat isfaction and general characteristics of nurses in the various other organizational patterns. 4. Nurses in hospitals where nursing is organizationed as an independent department perceived their organizatianal pattern more positively and had higher job satisfaction than nurses working in hospitals where nursing is part of another department. 5. There were differences between perceived organizational characteristics and job satisfaction according to the organizational patterns for nursing (F=13.52, 8.76, p=.0000). 6. There were correlations between the perceived organizational characteristics and job satisfaction of nurses working in two independent nursing departments (r=0.2180, 2351, p〈.05). In conclusion, the relationship between perceived organizational characteristics and job satisfaction was significantly correlated in the hospitals where the nursing department is independent. Perceived organizational characteristics and job satisfaction depended on whether the nursing department is independent from or attached to other departments in the hospital. For nurses job satisfaction the nursing department should be independent from other departments and at the highest level of organization in the hospital.

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땅밀림 우려지의 토양 및 지질환경 특성에 관한 통계적 분석 (Statistical Analysis of Soil and Geological Environment Characteristics in Slow-moving Landslide Prone Areas in the Republic of Korea)

  • 양대성;임상준;서정일;봉태호;김동엽
    • 한국산림과학회지
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    • 제113권3호
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    • pp.382-392
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    • 2024
  • 이 연구는 국내에서 발견된 땅밀림 우려지와 일반산지 간의 토양 및 지질환경 특성값의 차이를 규명하기 위하여 실시되었다. 2019~2021년 3년간의 땅밀림 실태조사 결과에서 최종적으로 땅밀림 우려지로 판정된 107개소와 일반산지로 판정된 193개소 등 총 300개소에 대하여, 11개의 토양 및 지질환경 특성 인자를 각각 측정하였다. 땅밀림 우려지와 일반산지 등 두 집단 간의 특성 요인별 차이점을 파악하기 위하여 T-검정을 실시하였으며, 표본집단의 분포 특성을 고려하여 비모수검정인 χ2-검정 및 밀도그림 작성을 추가적으로 실시하였다. 그 결과, 토양 내부마찰각, 풍화암 층후, 기반암 층후, 주요 지질 이상대 개수 요인에서 두 집단 간에 통계적으로 유의한 특성값 차이가 나타났다. 결론적으로 국내 땅밀림 우려지는 일반산지와 비교하여 지층 층후 및 이상대 존재 유무 등 지질환경 특성에서 차이가 나는 것을 확인할 수 있었다. 추후 이 연구에서 규명된 지질환경 특성과 땅밀림 발생의 인과관계에 대한 명확한 이해를 위해서, 지속적인 현장 자료 확보 및 체계적인 분석이 필요할 것으로 생각되었다.

혁신형 중소기업의 재무적 제약과 배당스무딩간의 관계 (The Relations between Financial Constraints and Dividend Smoothing of Innovative Small and Medium Sized Enterprises)

  • 신민식;김수은
    • 중소기업연구
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    • 제31권4호
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    • pp.67-93
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    • 2009
  • 본 연구는 1999년 1월 1일부터 2007년 12월 31일까지 한국거래소의 유가증권시장과 코스닥시장에 상장된 혁신형 중소기업을 대상으로 재무적 제약과 배당스무딩간의 관계를 실증분석 하였으며, 주요한 분석결과는 다음과 같다. 기업들은 목표 배당성향을 가지고 있으며, 실제 배당성향이 목표 배당성향에서 이탈하면 다시 배당지급을 부분적으로 조정한다. 배당조정속도는 Lintner(1956)의 배당조정모형의 핵심변수인 전기 주당배당과 당기 주당이익을 사용하여 거의 대부분 측정할 수 있으며, 잔여배당이론과 그 이후에 등장한 배당신호이론, 대리인이론, 케이터링 이론 및 거래비용이론에 관한 대용변수들은 배당조정속도에 부분적으로 영향을 미친다. 그리고 전기 주당배당은 당기 주당이익보다 배당조정속도에 더 큰 영향을 미치는데, 이는 기업들이 특별한 이유가 없는 한 전기 주당배당 수준을 장기적으로 유지하는 안정적인 배당정책을 선호한다는 증거가 된다. 혁신형 중소기업은 비혁신형 중소기업보다 배당조정속도가 더 빠르다. 혁신형 중소기업은 R&D 투자에 따른 미래의 성장성과 수익성을 담보로 하여 장기적으로 안정적인 배당정책을 유지할 수 있다. 다시 말해, 혁신형 중소기업은 배당지급이 목표 배당성향에서 이탈하더라도, R&D 투자에 따른 미래의 성장성과 수익성을 담보로 하여 목표 배당성향을 향하여 배당지급을 신속하게 조정하여 배당스무딩을 효과적으로 달성할 수 있다. 그리고 혁신형 중소기업 중에서도 재무적 비제약 기업은 재무적 제약 기업보다 배당조정속도가 더 빠르다. 이는 재무적 비제약 기업일수록 자본시장을 통한 외부 자금조달이 용이하기 때문에 주당배당을 신속하게 조정한다는 증거가 된다. 따라서 자본시장 접근성이 용이하여 재무적 제약을 적게 받는 기업일수록 외부 자금조달이 용이하기 때문에 배당지급을 더 신속하게 조정함으로써 배당스무딩을 더 효과적으로 달성할 수 있다. 그리고 중소기업청이 정책적 목적으로 분류한 혁신형 중소기업(벤처기업, 이노비즈기업, 경영혁신형기업)은 비혁신형 중소기업보다 배당조정속도가 더 빠르다. 중소기업청에서 정책적 목적으로 분류한 혁신형 중소기업은 신용보증지원, 정책자금지원, 조세혜택, 공공입찰 우선권 부여 등과 같은 다양한 정책적 혜택으로 인해 재무적 제약을 적게 받기 때문에 배당지급을 더 신속하게 조정할 수 있다. 결론적으로, 한국거래소의 유가증권시장과 코스닥시장에 상장된 혁신형 중소기업은 비혁신형 중소기업보다 배당조정속도가 더 빠르고, 혁신형 중소기업 중에서도 재무적 비제약 기업은 재무적 제약 기업보다 배당조정 속도가 더 빠르다. 다시 말해, 중소기업 중에서도 R&D 집중도가 높은 혁신형 중소기업은 R&D 투자에 따른 미래의 성장성과 수익성을 담보로 하여 배당스무딩을 신속하게 할 수 있고, 혁신형 중소기업 중에서도 자본시장 접근성이 좋은 기업은 재무적 제약을 적게 받기 때문에 배당스무딩을 더 신속하게 할 수 있다. 따라서 중소기업 경영자는 R&D 집중도를 증가시키고 자본시장 접근성을 높여 재무적 제약을 회피함으로써 신속한 배당스무딩을 통해 장기적으로 안정적인 배당정책을 유지할 수 있다고 생각한다. 그리고 중소기업청이 정책적 목적으로 분류한 혁신형 중소기업(벤처기업, 이노비즈기업, 경영혁신형기업)의 경우에도 배당조정속도가 비혁신형 중소기업보다 더 빠르게 나왔다. 이러한 결과는 배당정책의 측면에서 중소기업청의 혁신형 중소기업 정책을 지지하는 실증적인 증거가 된다.