• 제목/요약/키워드: statistical limits

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유방전용감마카메라에서 유방 보형물이 영상에 미치는 영향에 관한 고찰 (A Study on Effect of the Image Applying to Breast Implants in Breast Specific Gamma Imaging)

  • 이주영;이태수;박훈희
    • 대한방사선기술학회지:방사선기술과학
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    • 제41권1호
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    • pp.33-38
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    • 2018
  • There are limits to check the lesion as inserting a breast implant patients. So the application of BSGI based on Nuclear Medicine examination has increased. In this study, therefore we confirmed the effect of the image applying to breast implants in Breast Specific Gamma Imaging. We utilized Dilon 6800 BSGI scanner and developed the phantom. The self-development phantom was a rectangular shape of $230{\times}190{\times}80mm$ size and had 5 spheres which consisted of diameters of 10, 13, 17, 22, 28 mm in central part. We injected $^{99m}TcO_4$ into the self-development phantom in the proportion of four to one and made each additional phantom filled with 0.9 % sodium chloride, silicon and paraffin. Each additional phantom was placed between detector and self-development phantom. Each image was acquired five times depending on the type and thickness of the additional phantom. Statistical analysis with SPSS ver.18 was applied. In the test of variation according to the thickness of all additional phantoms, as the phantoms which 0.9% sodium chloride, silicon and paraffin increased, the attenuation variation was higher(P<0.005). There was no significant difference in the attenuation variation and the quality of image for type of the additional phantom. Therefore, if the effect of the image applying to breast implants in Breast Specific Gamma Imaging is confirmed, the higher diagnostic value can be achieved.

Variations of SST around Korea Inferred from NOAA AVHRR Data

  • Kang, Yong-Q.;Hahn, Sang-Bok;Suh, Young-Sang;Park, Sung-Joo
    • 대한원격탐사학회지
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    • 제17권2호
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    • pp.183-188
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    • 2001
  • The NOAA AVHRR remotely sensed SST data, collected by the National Fisheries Research and Development Institute (NFRDI), are analyzed in order to understand the spatial and temporal distributions of SST in the sea near korea. Our study is based on 10-day SST images during last 7 years (1991-1997). For a time series analysis of multiple SST images, all of images must be consistent exactly at the same position by adjusting the scales and positions of each SST image. We devised an algorithm which automatically detects cloud pixels from multiple SST images. The cloud detection algorithm is based on a physical constraint that SST anomalies in the ocean do not exceed certain limits (we used $\pm$3$^{\circ}C$ as a criterion of SST anomalies). The remotely sensed SST data are tuned by comparing remotely sensed data with observed SST at coastal stations. Seasonal variations of SST are studied by harmonic fit of SST normals at each pixel and the SST anomalies are studied by statistical method. It was found that the SST anomalies are rather persistent for one or two months. Utilizing the persistency of SST anomalies, we devised an algorithm for a prediction of future SST. In the Markov lprocess model of SST anomalies, autoregression coefficients of SST anomalies during a time elapse of 10 days are between 0.5 and 0.7. The developed algorithm with automatic cloud pixel detection and rediction of future SST is expected to be incorporated to the operational real time service of SST around Korea.

학교폭력예방을 위한 무선호출기 시범사업 효과성에 관한연구 (Study on Effects of Radio Pager Demonstration Project on School Violence Prevention)

  • 이성대;박종옥;염동문
    • 재활복지공학회논문지
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    • 제8권2호
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    • pp.101-107
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    • 2014
  • 학교폭력예방을 위한 무선호출기에 대한 인식과 효과성을 알아보기 위해 무선호출기 시범사업에 참여하고 있는 청소년 606명을 대상으로 분석하였다. 분석결과 첫째, 학교폭력 피해경험 유무와 가해경험 유무에 따른 두 집단간의 통계적 차이를 확인한 결과 학교폭력 피해경험 학생과 가해경험 학생 모두 무선호출기기가 학교폭력 예방에 도움이 된다고 생각하고 있었으며, 무선호출기기를 지속적으로 사용하기를 희망하는 것으로 나타났다. 둘째, 무선호출기기가 학교폭력 예방에 미치는 영향을 알아본 결과 무선호출기 소지정도, 무선호출기 필요성향, 무선호출기 만족성향이 높을수록 학교폭력 예방과 학교생활만족도에 긍정적인 영향일 미치는 것으로 나타났다. 이러한 내용을 바탕으로 연구의 함의와 함께 제한점을 제시하였다.

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아이돌 휴먼브랜드의 특성이 소비자의 아이돌 휴먼브랜드 애착, 모방 욕구, 동일시 욕구와 패션 제품 구매 의도에 미치는 영향 (The Effects of Idol Human Brand's Characteristics on Consumer's Idol Human Brand Attachment, Desire to Imitate, Desire to Identify, and Purchase Intention)

  • 황지영;박민정
    • 한국의류산업학회지
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    • 제23권5호
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    • pp.559-575
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    • 2021
  • The popularity of K-pop, the development of diverse media and communications, and rapid globalization are increasing consumers' attachment to celebrities. These celebrities, called "Human brand", have a growing impact on consumers. However, research on idol celebrities has been conducted mainly on teenagers. Furthermore, there are limits to the studies on consumers' attachment to idol celebrities who do not advertise specific products and intention to purchase products which are not advertised but related to the idol human brand. Therefore, this study has been conducted on 301 out of 400 adult women in their twenties to forties in Korea to examine the relationship between the characteristics of the idol human brand, attachment to the idol human brand, desire to imitate the idol human brand, desire to identify with the idol human brand and its fandom community, and the effect on purchase intention. For the statistical analysis, SPSS and AMOS were used. The study found that the characteristics of the idol human brand which are trust, professionality, social attractiveness, and physical attractiveness positively influenced attachment to the idol human brand. The attachment to the idol human brand positively affected the imitation desire toward the idol human brand, and the identification desire with the idol human brand, and to identify with its fandom community. Additionally, the desire to imitate and to identify with the idol human brand and its fandom community positively affected the intention. Furthermore, the relationships between all variables were found to have a significant mediating effect.

Estimation of Lead Exposure Intensity by Industry Using Nationwide Exposure Databases in Korea

  • Koh, Dong-Hee;Park, Ju-Hyun;Lee, Sang-Gil;Kim, Hwan-Cheol;Jung, Hyejung;Kim, Inah;Choi, Sangjun;Park, Donguk
    • Safety and Health at Work
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    • 제12권4호
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    • pp.439-444
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    • 2021
  • Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results: A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion: Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

AEB 장치에 대한 사고경감 효과 연구 (Study on Effectiveness of Accident Reduction Depending on Autonomous Emergency Braking System)

  • 최준영;강승수;박은아;이강원;이시훈;조수강;권영길
    • 자동차안전학회지
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    • 제11권2호
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    • pp.6-10
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    • 2019
  • This paper describes effectiveness of accident reduction on vehicles equipped with AEB using accident data occurring in Korea. During the statistical period, we used the number of vehicles which are covered by auto insurance and the number of accidents. To maximize the reduction effect of accidents caused by the driver's carelessness, the analysis was limited to Physical Damage Coverage that covers the cost of repairing or replacing the damaged vehicle caused by the driver's fault. Due to Personal Information Protection Law, it was not capable of comparing the same vehicle using Vehicle Identification Number in this study. Instead of that, we used it as a similar vehicle, so there are limits to the comparison and analysis results. As a result of this study, we have found that the effect of reducing accidents was different depending on the vehicle class, but it was generally concluded that the number of accidents decreased when the vehicle was equipped with an AEB system. Domestic research on the AEB effect of reducing accidents is not active yet. Therefore, it is absolutely essential to analyze the effects according to various conditions such as driver's age, occupation and gender as well as expanding the study models in the future.

Ten Tips for Performing Your First Peer Review: The Next Step for the Aspiring Academic Plastic Surgeon

  • Frendo, Martin;Frithioff, Andreas;Andersen, Steven Arild Wuyts
    • Archives of Plastic Surgery
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    • 제49권4호
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    • pp.538-542
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    • 2022
  • Performing the first peer review of a plastic surgical research article can be an overwhelming task. However, it is an essential scholarly skill and peer review is used in a multitude of settings: evaluation of journal articles, conference abstracts, and research proposals. Furthermore, peer reviewing provides more than just the opportunity to read and help improve other's work: peer reviewing can improve your own scientific writing. A structured approach is possible and recommended. In these ten tips, we provide guidance on how to successfully conduct the first peer reviews. The ten tips on peer reviewing concern: 1) Appropriateness: are you qualified and prepared to perform the peer review? 2) Familiarization with the journal and its reviewing guidelines; 3) Gathering first impressions of the paper followed by specific tips for reviewing; 4) the abstract and introduction; 5) Materials, methods, and results (including statistical considerations); and 6) discussion, conclusion, and references. Tip 7 concerns writing and structuring the review; Tips 7 and 8 describe how to provide constructive criticism and understanding the limits of your expertise. Finally, Tip 10 details why-and how-you become a peer reviewer. Peer review can be done by any plastic surgeon, not just those interested in an academic career. These ten tips provide useful insights for both the aspiring and the experienced peer reviewer. In conclusion, a systematic approach to peer reviewing is possible and recommended, and can help you getting started to provide quality peer reviews that contribute to moving the field of plastic surgery forward.

예비사서의 경력 미결정 요인에 관한 연구 (A Study on the Antecedents of Career Indecision for Prospective Librarians)

  • 최정희;최병우;안인자
    • 한국비블리아학회지
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    • 제17권1호
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    • pp.265-283
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    • 2006
  • 본 연구는 예비사서들의 경력 미결정 수준에 미치는 영향력을 분석하기 위해서 수도권 및 충청권 소재 문헌정보학과 재학생을 대상으로 실증연구를 하였다. 외생변수로는 인적특성, 학교 조직적 특성 그리고 제도적 특성으로 설정하여 조사하였다. 구조방정식모형을 이용하여 분석한 결과, 대학생들의 인적특성이 경력 미결정 수준에 영향을 미친다는 것이 밝혀졌으나, 조직특성 및 제도적 특성은 경력 미결정 수준에 통계적 유의성을 보여주지 못하였다. 이는 예비사서로서의 경력 결정수준을 높이기 위해서는 직업적 자아정체감 및 자기 효능감을 향상시킬 수 있는 자기개발 프로그램의 개발과 아울러 교과과정, 현장 사서가 갖추어야 할 실무능력, 사서자격제도 개선 등의 학교 조직적 제도적 차원의 지원이 뒤따라야 함을 시사하는 것이다. 끝으로, 이와 같은 결과를 토대로 연구의 한계점 및 추후 연구방향에 대하여 논의하였다.

Application of a Semi-Physical Tropical Cyclone Rainfall Model in South Korea to estimate Tropical Cyclone Rainfall Risk

  • Alcantara, Angelika L.;Ahn, Kuk-Hyun
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.152-152
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    • 2022
  • Only employing historical data limits the estimation of the full distribution of probable Tropical Cyclone (TC) risk due to the insufficiency of samples. Addressing this limitation, this study introduces a semi-physical TC rainfall model that produces spatially and temporally resolved TC rainfall data to improve TC risk assessments. The model combines a statistical-based track model based on the Markov renewal process to produce synthetic TC tracks, with a physics-based model that considers the interaction between TC and the atmospheric environment to estimate TC rainfall. The simulated data from the combined model are then fitted to a probability distribution function to compute the spatially heterogeneous risk brought by landfalling TCs. The methodology is employed in South Korea as a case study to be able to implement a country-scale-based vulnerability inspection from damaging TC impacts. Results show that the proposed model can produce TC tracks that do not only follow the spatial distribution of past TCs but also reveal new paths that could be utilized to consider events outside of what has been historically observed. The model is also found to be suitable for properly estimating the total rainfall induced by landfalling TCs across various points of interest within the study area. The simulated TC rainfall data enable us to reliably estimate extreme rainfall from higher return periods that are often overlooked when only the historical data is employed. In addition, the model can properly describe the distribution of rainfall extremes that show a heterogeneous pattern throughout the study area and that vary per return period. Overall, results show that the proposed approach can be a valuable tool in providing sufficient TC rainfall samples that could be an aid in improving TC risk assessment.

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원자력발전소 온배수 영향 해양물리분야 조사의 표준지침 (A Standard Guide to Physical Oceanographic Survey of the Effect of Thermal Discharge from a Nuclear Power Plant)

  • 이재학;노영재;조양기
    • 한국해양학회지:바다
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    • 제12권1호
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    • pp.43-49
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    • 2007
  • 원자력발전소 온배수 영향 조사 과정상 문제점을 평가하고 대안으로서 조사 표준 지침을 제시하였다. 관측이나 온배수 확산 모델링 단독으로 이루어진 지금까지의 방법으로는 시간에 따른 온배수에 의한 수온 분포의 변화를 정량적으로 파악하는데 한계가 있으므로, 관측과 온배수 확산 수치모델링의 상호 보완적인 조사를 병행하는 것이 바람직하다. 현장 관측은 원자력발전소 인근 해역의 모든 자연적 열원의 영향을 고려한 열수지 모형의 개념에 근거한 조사가 중요하며, 수치모델링의 결과를 기준 수온분포로서 활용하고자 할 경우에는 수치모델링에 의한 현상 재현이 통계적 유의수준에 도달한 경우에 한정하도록 하였다. 또한, 과거의 순환 및 확산 모델링의 문제점을 개선하기 위한 대안으로서 표준코드의 개발을 제안하였다.