• 한국조경학회지
• /
• 제21권4호
• /
• pp.29-41
• /
• 1994

The purposes of this study are (a)to investigate the effect of follow-up on the increase of response rate;(b)to analyze the effect of follow-up on the statistics by predetermined response rates ; therefore, (c)to describe the importance of high response rate and to suggest methods in order to increase response rate in mail survey. Telephone directory of Seoul was utilized as a sampling frame, and modified Total Design Method(TDM) was applied to collect the data. The results are summarized as follows. 1. Final response rate was 76.5% by 2 follow-ups. 2. The first follow-up with telephone call had a significant effect on increase of response rate. As a result, follow-up by postcard in TDM could be omitted in this method. 3. The second follow-up by registered mail did not have a significant effect. Therefore, use of this procedure is depending upon such research situtations as importance of high response rate and cost available. 4. Follow-ups helped to make collected sample highly representative. 5. Most questionnaires were arrived on the first half of data collection period in each follow-up. 6. Most of questionnaires were collected for 10 weeks. Accumulated responses could be fitted by exponential and logistic curve, simultaneously. The fitted curve suggested that eventually limited number of questionnaires by arrived. So, if researchers want higher response rate, they have to conduct more follow-ups. 7. Statistics in the predetermined response rate were not changed significantly. But replications are needed to generalize this result.

• KDI Journal of Economic Policy
• /
• 제40권2호
• /
• pp.75-96
• /
• 2018

Recently, the government has been pursuing various policies to create new industries and jobs through the invigoration of start-ups. For the sustained growth of start-ups, it is necessary to look not only at the supply of risk capital but also at policies for venture capital firms that nurture and foster start-ups. The purpose of this study is to estimate the effects of the nurturing and fostering role of risk capital, such as mentorship on the performance of start-ups, and to do this we analyzed the effects, as a newly introduced form of venture capital, of mentoring by an accelerator and investor ties on the performance outcomes of start-ups. We find that mentoring and investor ties for start-up enterprises positively influence follow-up investment in start-ups. In addition, this study finds that with a younger CEO of a start-up, it is more likely that the performance of the start-up will improve. Meanwhile, when examining increases in employment as a measure of the business performance of start-ups, mentoring and investor ties are found to have a positive effect on the increase of employment at start-ups. These results suggest that there is a need to promote policies that strengthen the mentoring role of venture capital in Korea's equity finance policies and in the government's SME support policies.

• 대한소아치과학회지
• /
• 제45권3호
• /
• pp.324-333
• /
• 2018

유년기는 치열변화, 치아우식 등 전반적으로 변화가 많은 시기로, 구강질환 예방 및 조기치료를 위해 정기적 내원이 필요하다. 본 연구는 진정법 하 치과치료 후 정기검진 패턴에 영향을 미치는 요인을 파악하고자 했다. 2009년부터 2013년까지 이대목동병원 소아치과에서 진정법 하 치과치료를 받은 환자 562명을 3년간 내원 횟수에 따라 4개의 군으로 분류한 뒤, Chi-square test를 이용하여 정기검진에 영향을 미치는 요인을 파악했다. 내원 기간 동안 주치의 변경, 진정법 하 치료한 치아 개수, 총 치료시간, 수복치료, 소수술, 예방적 치료는 재내원 그룹과 통계적으로 유의한 차이가 있었다(p < 0.05). 소수술을 받은 환자 및 우식 이환 치아 개수가 적거나 중등도인 환자의 경우 재내원 가능성이 낮으므로, 보호자에게 치료의 예후관찰 및 구강질환 예방을 위해 정기검진이 필요함을 강조해야 할 것이다.

• Environmental Analysis Health and Toxicology
• /
• 제31권
• /
• pp.23.1-23.6
• /
• 2016

Objectives A stable follow-up participation rate is a very important factor for validity in a cohort study. This study analyzed the factors that affect the participation rate at one hospital-based birth cohort in South Korean. Methods The participants were recruited from the Mothers' and Children's Environmental Health study between 2006 and 2010. The analysis targeted 1751 mothers who participated in a birth cohort. We conducted analyses of general characteristics during pregnancy and those of infants at birth that affect the participation rate of the 6-month follow-up survey. Results The participation rate for the 6-month follow-up survey was 60.4%. The participation rate in the follow-up of the subsequent period decreased within a 5% to 10% range compared to the number of subjects. The participation rate of premature infants was 16.9% lower than that of a full-term infant (52.6% vs. 69.5%). Analysis showed a 16.7% difference between the participation rate of low-birthweight infants in follow-ups (53.7%) and the participation rate of infants with normal weight (70.4%). The participation rate of mothers who were employed during pregnancy was significantly lower for the 6-month follow-up compared to the participation rate of mothers who were unemployed during pregnancy. Conclusions In this study, factors such as premature birth, low-birthweight, and the employment status of the mother during pregnancy affected the participation rate of the follow-up survey for the birth cohort at six months. A specific strategy is needed to encourage survey participation for the high risk groups in the follow-ups.

• Journal of Korean Neurosurgical Society
• /
• 제55권1호
• /
• pp.12-17
• /
• 2014

Objective : Anterior cervical discectomy and fusion (ACDF) is often complicated by subsidence, pseudoarthrosis, kyphosis, and graft donor site morbidities. To decrease the occurrence of these complications, various types of cages have been developed. We designed this retrospective study to analyze and compare the efficacy and outcomes of ACDF using double cylindrical cages (DCC) (BK Medical, Seoul, Korea) versus an anterior cervical plating system with autogenous iliac crest grafts. Methods : Forty-eight patients were treated with autograft and plating (plate group), and 48 with DCC group from October 2007 to October 2011. We analyzed construct length, cervical lordotic curvarture, the thickness of the prevertebral soft tissue, segmental instability, and clinical outcomes. Results : There were no significant differences between the two groups with regard to the decrease in construct length or cervical lodortic curvature at the 3-, 6-, and 12-month follow-ups. The prevertebral soft tissue was thinner in the DCC group than the plate group immediately after surgery and at the 3-, 6-, and 12-month follow-ups. The difference in interspinous distance on flexion-extension was shorter in the plate group than the DCC group at the 3- and 6-month follow-ups. However, there was no significant difference in this distance between the two groups at the 12-month follow-up. Conclusion : A double cylindrical cage is a good alternative for fusion in patients with cervical degenerative diseases; the surgical method is relatively simple, allows good synostosis, has less associated prevertebral soft tissue swelling, and complications associated with autografting can be avoided.

• 가정과삶의질연구
• /
• 제21권5호
• /
• pp.93-107
• /
• 2003

The purpose of this study was to verify the effectiveness of sociodrama on adolescents who are maladjusted in school. For this study, nine adolescents were selected from a middle school located in Seoul. The Inventory of School adjustment by Bae Sook-Jin, Buss-Durkee Hostility Inventory(BDHI) and Impulsivity Test by Eysenck were administered. The experiment group acted out a sociodrama twelve times. The first follow-up test was conducted twelve weeks after the pre-test. The second follow-up test was conducted six weeks after first follow-up test. Each time the adolescents acted out a sociodrama their behavior was recorded by a video- camera and then documented by research assistants. Also in order to discover any changes in daily life after sociodrama, an interview survey were done with the adolescents' teachers. The findings were as follows. First, in the initial follow-up test degree of school-maladjustment was less than in the pre-test. Further decreases in the level of maladjustment were noted in the subsequent follow-ups. Therefore, it can be concluded that the performance of sociodramas can reduce school-maladjustment among adolescents and that this reduced level is maintained. Second, the level of hostility discovered in the first follow-up test was less than that in the pre-test, and this level continued to decrease in the following follow-ups. Therefore, we may conclude that sociodrama that reduces adolescent hostility and the reduced levels continue. Finally, the degree of impulse detected in the first follow-up was, once again, less than that of the pre-test, And, as in the other cases, there was a continued decrease in this level. We may therefore conclude that sociodrama does reduce the impulse of adolescents and that this reduction is maintained. This study indicates that sociodrama is an effective method to improve the psychological characters of adolescents who are maladjusted in school. Given the above, a follow up study is suggested.

• 디지털융복합연구
• /
• 제16권6호
• /
• pp.1-8
• /
• 2018

이 논문의 목적은 첫째 온라인에서 학습활동을 하는 e-러닝 이용자의 사후 태도에 영향을 미치는 선행요인을 파악하고, 어떤 요인들이 사후태도에 주로 영향을 미치는가를 파악하는 것이다. 둘째, 한국, 베트남, 싱가폴의 e-러닝 사용자들을 조사 대상으로 하여 3개국 간에 사회적, 문화적, 지리적 차이에 따라 e-러닝과 관련된 선행요인과 사후태도에 유의한 차이가 있는가를 파악하는 것이다. 이 논문에서는 ANOVA 기법을 사용하여 e-러닝 선행요인에 차이가 있는지 확인했으며, 회귀분석을 통하여 3개 국가별로 어떠한 선행요인이 e-러닝 후행요인에 영향을 주는지 밝히고, 국가간 차이를 확인하였다. 분석결과 국가간에 선행요인에 차이가 있었으며, 각 국가별로 e-러닝 후행요인에 영향을 미치는 선행요인도 차이를 발견할 수 있었다. 발견된 국가별 차이점은 각국의 e-러닝 사업 실무자에게 의미있는 시사점을 제공할 수 있다. 향후 조사대상을 초중고생에까지 확대 연구할 수 있을 것이다.

• Nutrition Research and Practice
• /
• 제15권1호
• /
• pp.38-53
• /
• 2021

BACKGROUND/OBJECTIVES: Abdominal obesity is associated with metabolic disorders, and, in recent years, its prevalence in Korea has continuously increased. The change of lifestyle, particularly diet, is critical for the reduction of abdominal obesity. This study evaluated the effectiveness of an intervention focused on dietary self-efficacy and behaviors on the improvement of abdominal obesity. SUBJECTS/METHODS: Abdominally obese adults with additional cardiovascular risk factors were recruited through 16 medical facilities in South Korea from the year 2013 to 2014. The participants were randomly divided into 2 groups: an intensive intervention group (IG) that received a multi-component intervention to reduce abdominal obesity, by mainly focusing on dietary attitude and dietary behavior change, and a minimal information intervention group (MG) that received a brief explanation of health status and a simple recommendation for a lifestyle change. The interventions were provided for 6 mon, and health examinations were conducted at baseline, 3-, 6-, and 12-mon follow-ups. A path analysis was conducted to identify the process governing the changes in abdominal obesity. RESULTS: The IG showed an improvement in self-efficacy for eating control and diet quality at 6-mon follow-up. Abdominal obesity improved in both groups. Waist circumference was observed to be decreased through the path of "improved self-efficacy for eating control in food availability-eating restriction-improved dietary quality" in IG. Most changes in follow-ups were not significantly different between two groups. CONCLUSIONS: The intensive program targeting the modification of dietary behavior influenced management of abdominal obesity, and the effect occurred through a step-by-step process of change in attitude and behavior. Generally, improvements were also seen in the MG, which supports the necessity of regular health check-ups and brief consultation. The results can be used for further development and implementation of more successful interventions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제46권4호
• /
• pp.282-287
• /
• 2020

Undifferentiated pleomorphic sarcoma (UPS) is a high-grade neoplasm that is usually located in the extremities and retroperitoneum. In the past, UPS was considered the most common soft tissue sarcoma in adults; due to improvements in diagnostic techniques, most cases have been reclassified as other lineage-specific tumors. Gnathic bones are rarely affected, and the clinicopathological characteristics of this neoplasm when diagnosed in the jaw remain to be better described. In this report, we present a rare case of mandibular UPS affecting an 88-year-old female who demonstrated a painful swelling on the right side of the mandible that was accompanied by a pathological fracture. Microscopic examination revealed a pleomorphic spindle-cell neoplasm with mitotic figures and necrosis. The patient underwent surgery and adjuvant radiotherapy but experienced metastasis after 12 months of follow-up and died. Diagnosis of UPS is challenging, and oral pathologists must be aware of this entity when dealing with aggressive undifferentiated neoplasms.

• Journal of the Korean Statistical Society
• /
• 제29권4호
• /
• pp.385-394
• /
• 2000

Jackknife variance estimation based on adjusted imputed values when nonresponse is nonrandom and follow-up data are available for a subsample of nonrespondents is provided. Both hot-deck and ratio imputation method are considered as imputation method. The performance of the proposed variance estimator under nonrandom response mechanism is investigated through numerical simulation.