• Journal of the korean academy of Pediatric Dentistry
• /
• v.44 no.1
• /
• pp.56-63
• /
• 2017

Delayed eruption of the first molar, without a generalized or localized cause, is usually associated with delayed development of the affected tooth. The aim of this study was to investigate the clinical features of the first permanent molar showing delayed development and eruption, and its association with developmental anomalies of other teeth. Panoramic radiographs of 40 healthy children showing delayed development and eruption of first permanent molars were analyzed. The clinical features of affected first molars and developmental anomalies of other teeth (except third molars) were evaluated. Delayed first molars were more frequent in the maxilla. The incidence of bilateral delayed development of first molars was greater than that of unilateral cases in female patients. In contrast, male patients showed unilateral delayed development of the first molar more frequently. A higher incidence of congenitally missing teeth was observed in patients with delayed first molar. In each case, delayed development or congenital absence was observed in the second molar adjacent to the delayed first molar. Overall, delayed first molar seems to be associated with congenital absence of additional teeth. Understanding the developmental mechanisms of this phenomenon requires further studies.

• 레미콘
• /
• no.9 s.9
• /
• pp.70-76
• /
• 1986

다음 내용은 8월 29일 광주에서 열린 전남도 공장새마을 품질관리 경진대회에서 중원산업(주) 광주공장 분임조가 발표한 활동사례를 요약한 것이다.

• Proceedings of the Korean Association for Survey Research Conference
• /
• 2006.06a
• /
• pp.225-233
• /
• 2006

• Proceedings of the Korean DIstribution Association Conference
• /
• 2006.08a
• /
• pp.21-46
• /
• 2006

본 연구에서는 인터넷 쇼핑몰에서 불만족을 경험한 고객들의 불평요인 및 불평행동유형을 파악하고, 쇼핑몰 업체의 불평처리방법에 대한 평가를 바탕으로 효과적인 불평처리방안을 제시하였다. 연구 결과 불평행동을 하는 고객의 유형은 직접행동파, 사적행동파, 소극행동파, 적극행동파 등으로 구분되었다. 이 가운데 사적행동파가 가장 높게 나타나 인터넷 환경에서는 사적행동파에 대한 효과적인 불평처리 방안에 관한 노력이 가장 필요한 것으로 확인되었다. 직접행동파는 해당 쇼핑몰 업체에게 직접 문제해결을 요구하기 때문에 불평처리에 대한 공정성, 불평 후 만족과 충성도 측면에서 가장 효과적인 것으로 확인되었다. 그리고 고객의 모든 불평행동유형에서 가장 심각한 불만족 요인으로는 배송오류 및 지연과 제품결함인 것으로 확인되었지만, 사적행동파와 소극행동파는 부정확한 정보제공과 과장광고 등을 심각하게 생각하고 있었다. 인터넷 쇼핑몰 업체는 불평고객들의 불평해결을 위해 직접적인 접촉을 할 경우 가장 효과적인 불평처리를 할 수 있기 때문에 사적행동파와 소극행동파의 불평행동을 유발하기 위한 노력이 필요하다. 또한 쇼핑몰 관리자의 불친절 및 반응은 심각한 불만족 요인은 아니지만, 배송오류 및 지연과 제품결함과 같은 심각한 불만족요인에 대해서는 직접적인 사과 및 쇼핑몰 관리자의 친절한 태도를 포함하여 현금 환불 등 불평처리를 해야 한다. 그리고 고객의 관점에서 인터넷 쇼핑몰을 보다 편리하고 유용하게 설계할 필요가 있다.

• Journal of the Korean Chemical Society
• /
• v.44 no.4
• /
• pp.328-336
• /
• 2000

The pulsed-delayed extraction (PDE) in linear time-of-flight mass spectrometer(TOF MS) is characterized on the enhancement of resolution, mass-depth of focus and effect of instrumentahan 2000. The ion signals separate isotopically by up to molecular weight of 2500 in instrumental broadening of 5 ns, which is a good agreement with calculation. The fragmentation paths of PPG can be sug-gested by the isotopica distributions of fragment series produced when PPG desorbed from graphite surface.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37A no.10
• /
• pp.895-902
• /
• 2012

In this paper, we propose a novel equalizer to compensate for the group delay including AM/PM nonlinear distortion characteristics by the nonlinear power amplifier (PA). The group delay characteristic is a nonlinear non-constant time delay that appears differently depending on each frequency component. The phase distortion by AM/PM characteristics arising from the power amplifier is a major factor to increase group delay. By the group delay distortion, the signal in the constellation expands and is rotated. Considering the problem mentioned above, the nonlinear time delay that appears differently depending on each frequency component is classified as a static group delay and AM/PM characteristic of PA, the different phase transitions depending on the size of input signal as a dynamic group delay. Static group delay estimates and compensate for phase distortions in the frequency domain with type-based method and dynamic group delay compensates for phase rotation in the time domain. We confirmed that the group delay compensation techniques were enough to compensate the group delay characteristics including AM/PM characteristics of the power amplifier.

• Journal of Convergence for Information Technology
• /
• v.11 no.2
• /
• pp.138-145
• /
• 2021

The purpose of this study was to investigate the mediating effects of academic procrastination behavior on the relationship between academic stress and dropout intention. The research questions are First, does the academic stress of college students influence the intention to drop out? Second, does academic procrastination behavior the relationship between academic stress and dropout intention? A survey was conducted on 218 college students about academic stress, dropout intention, and academic procrastination behavior. Correlation analysis was conducted to find out the relationship between academic stress, dropout, and academic procrastination behavior, and Multiple regression analysis was performed to determine the moderating effect of academic procrastination behavior. The mediating effect was verified using Baron and Kenny's procedure, and the significance was verified by Sobel verification. The results are as follows: First, academic stress, dropout intention, and academic delay behavior showed significant positive correlations.. Second, Academic stress showed 15% of explanatory power as an influential factor on dropout intention, and 5% of explanatory power was an influential factor on academic procrastination behavior. Third, the through mediation analysis, there was partial mediated effects of academic procrastination behavior between academic stress and dropout intention. Our findings suggest that to improve the dropout intention among college students, educators should carefully design and develop an education program

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2012.04a
• /
• pp.178-181
• /
• 2012

이 연구 대상자는 일개 대학병원 응급의료센터로 소방구급대를 통해 내원한 환자 중 컴퓨터 단층촬영으로 뇌졸중으로 진단된 환자에서 이송 시 환자평가 시행에 영향을 미치는 요인을 분석한 연구이다. 연구결과 환자 평가에 영향을 미치는 요인은 환자분류(응급, 비응급, 지연), 의식상태(AVPU 척도)보다는 구급대원 자격별이 병원 전 뇌졸중 환자 이송 시 환자평가 시행에 영향을 미치는 것으로 확인되었다.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.05a
• /
• pp.119-120
• /
• 2015

Appropriate management of the finish works in construction project is one of most important activities that must be conducted considering the total duration of the project. Masonry work is a fundamental process that is performed in the preliminary steps of finish works. However, it has been investigated that the analysis of delay factors affecting masonry work has been neglected in the domestic construction site. Therefore, this study deducts delay factors affecting masonry work by literature review and survey on site engineers and labors. This study has been conducted as a preliminary step of developing a construction project interference management system which is expected to suggest objective information for the decision making in construction sites.

• Fire Science and Engineering
• /
• v.32 no.2
• /
• pp.57-66
• /
• 2018

The most urgent requirement in the event of disaster and fire in a skyscraper is to establish a system that enables people inside to evacuate safely. Hence, a practical direction needs to give evacuees confidence in the evacuation by reducing the psychological anxiety caused by the relatively large number of people inside and at the same time, the physically prolonged evacuation travel line. Evacuation tests with large numbers of people were conducted three times to solve these challenges and identify phenomena and issues that occurred during the experiment. The results revealed the factors that could cause a delay in evacuation and suggested improvements. The study results of this paper are as follows. First, a recent fire at a multipurpose high-rise resulted in a number of casualties due to a lack of experience with the disaster prevention system. To prevent such cases from occurring in advance, adaptability was achieved by conducting evacuation tests. Second, the data collected in the evacuation simulation statistics and the actual escape drills were compared and analyzed. Third, in the evacuation experiment, a large number of people could not participate in the experiment. The reasons for not participating were analyzed and their impact on the actual evacuation time was confirmed. Fourth, equipment aids were purchased to establish the optimal response measure to the causes of a delay in escape time and the standards for ensuring the safety of the evacuee were specified by developing improvements to minimize the evacuation delay time through comparative before and after analysis of the experiment. These results can be used for fire safety control of skyscrapers to improve the efficiency of evacuation.