• Journal of Korean Dental Science
• /
• 제13권2호
• /
• pp.73-80
• /
• 2020

Purpose: The purpose of this case study series was to introduce successful implant cases that used the palatal bone in patients with severe maxillary alveolar bone atrophy or defects. Case Presentation: In this case series study, a total of four patients underwent implant placement in the palatal bone of the maxilla. A total of 6 implants were installed using the palatine bone. The patients' ages ranged from 40 to 73 years with an average age of 63.5 years. The patients had maxillary sinus-related diseases, such as maxillary sinusitis, oroantral fistula, and dentigerous cysts, prior to implantation. To achieve initial stability, the implants were placed on the palatal side, and buccally tilted. The average postoperative recovery period was 8 months. No postoperative complications occurred in any of the cases, and the approach was used without reported issues. Conclusion: Implant treatment by securing the initial fixation in the palatal bone is a good alternative when an implant must be installed in a patient who requires extensive and invasive bone graft.

• 한국콘텐츠학회논문지
• /
• 제10권9호
• /
• pp.251-258
• /
• 2010

위절제술을 시행한 위암환자를 대상으로 수술 전 위치확인을 위한 위장조영검사의 영상을 분석하여 위암묘출의 정확도 및 한계성을 알아보고, 이에 따른 대응책을 알아보고자 하였다. 2007년 10월부터 2009년 4월까지 본원에 내원하여 병리조직학적으로 위암으로 확진되어 위절제술을 시행한 조기위암 환자 88명과 조기위암과 비슷한 진행성위암 환자 14명을 대상으로 하여, 수술 전 시행했던 위장조영검사와 수술 후 병리학적 소견을 비교분석하였으며, 영상분석은 10년 이상 근무한 방사선사 2명이 분석하였다. 위암환자 102명의 위절제 후 병리학적 위암위치와 비교를 통한 위장조영검사에서 위암의 발견율은 "확실" 81 예(79.4%), "실패" 21예(20.6%)로 판정되었다. "실패"로 판정된 21예의 위암형태는 IIb+IIc형이 2예(100%), IIb형이 5예(83.3%)로 발견율이 매우 낮았다. 위암의 전구병변인 장형화생은 위장조영검사에서 92예 (90.2%)의 발견율을 보였다. 위장조영검사의 한계점은 IIb형 및 1.0cm이하 미소위암의 발견이 어려웠다. 위암과 동반된 장형화생 92예(90.2%)의 발견은 위장조영검사에서 위암의 발견에 중요한 기준으로 평가된 다. 위장조영검사의 한계점을 극복하기 위해서는 부위에 맞는 정확한 촬영법 및 풍부한 방사선학적 경험을 통한 미세한 점막의 변화를 확인하는 촬영습관이 위암을 발견하는데 기여할 것으로 사료된다.

• Communications for Statistical Applications and Methods
• /
• 제16권2호
• /
• pp.335-348
• /
• 2009

Fuzzy regression is used as a complement or an alternative to represent the relation between variables among the forecasting models especially when the data is insufficient to evaluate the relation. Such phenomenon often occurs in seasonal time series data which require large amount of data to describe the underlying pattern. Semiparametric model is useful tool in the case where domain knowledge exists about the function to be estimated or emphasis is put onto understandability of the model. In this paper we propose fuzzy semiparametric support vector regression so that it can provide good performance on forecasting of the seasonal time series by incorporating into fuzzy support vector regression the basis functions which indicate the seasonal variation of time series. In order to indicate the performance of this method, we present two examples of predicting the seasonal time series. Experimental results show that the proposed method is very attractive for the seasonal time series in fuzzy environments.

• 한국통계학회:학술대회논문집
• /
• 한국통계학회 2005년도 춘계 학술발표회 논문집
• /
• pp.185-190
• /
• 2005

For the almost certainly convergent series $S_n$ of independent random variables the limiting behavior of tail series ${T_n}{\equiv}S-S_{n-1}$ is reviewed. More specifically, tail series strong laws of large number and tail series weak laws of large numbers will be introduced, and their relationship will be investigated. Then, the relationship will also be extended to the case of Banach space valued random elements, by investigating the duality between the limiting behavior of the tail series of random variables and that of random elements.

• Kyungpook Mathematical Journal
• /
• 제52권3호
• /
• pp.347-357
• /
• 2012

When Newton's method, or Halley's method is used to approximate the pth root of 1-z, a sequence of rational functions is obtained. In this paper, a beautiful formula for these rational functions is proved in the square root case, using an interesting link to Chebyshev's polynomials. It allows the determination of the sign of the coefficients of the power series expansion of these rational functions. This answers positively the square root case of a proposed conjecture by Guo(2010).

• 한국수학교육학회지시리즈A:수학교육
• /
• 제57권4호
• /
• pp.353-369
• /
• 2018

This study started with the following questions. Suppose that students do not accept various forms of geometric series tasks as the same task. Also, let's say that the approach was different for each task. Then, when they realize that they are the same task, how will students connect the different approaches? This study is a process of pro-actively confirming whether or not such a question can be made. For this purpose, three students in the second grade of high school participated in the teaching experiment. The results of this study are as follows. It also confirmed how the students think about the various types of tasks in the geometric series. For example, students have stated that the value is 1 in a series type of task. However, in the case of the 0.999... type of task, the value is expressed as less than 1. At this time, we examined only mathematical expressions of students approaching each task. The problem of reachability was not encountered because the task represented by the series symbol approaches the problem solved by procedural calculation. However, in the 0.999... type of task, a variety of expressions were observed that revealed problems with reachability. The analysis of students' expressions related to geometric series can provide important information for infinite concepts and limit conceptual research. The problems of this study may be discussed through related studies. Perhaps more advanced research may be based on the results of this study. Through these discussions, I expect that the contents of infinity in the school field will not be forced unilaterally because there is no mathematical error, but it will be an opportunity for students to think about the learning method in a natural way.

• 품질경영학회지
• /
• 제50권4호
• /
• pp.701-716
• /
• 2022

Purpose: This study aims to predict the dry cargo transportation market economy. The subject of this study is the BDI (Baltic Dry Index) time-series, an index representing the dry cargo transport market. Methods: In order to increase the accuracy of the BDI time-series, we have pre-processed the original time-series via time-series decomposition and data augmentation techniques and have used them for ANN learning. The ANN algorithms used are Multi-Layer Perceptron (MLP), Recurrent Neural Network (RNN), and Long Short-Term Memory (LSTM) to compare and analyze the case of learning and predicting by applying time-series decomposition and data augmentation techniques. The forecast period aims to make short-term predictions at the time of t+1. The period to be studied is from '22. 01. 07 to '22. 08. 26. Results: Only for the case of the MAPE (Mean Absolute Percentage Error) indicator, all ANN models used in the research has resulted in higher accuracy (1.422% on average) in multivariate prediction. Although it is not a remarkable improvement in prediction accuracy compared to uni-variate prediction results, it can be said that the improvement in ANN prediction performance has been achieved by utilizing time-series decomposition and data augmentation techniques that were significant and targeted throughout this study. Conclusion: Nevertheless, due to the nature of ANN, additional performance improvements can be expected according to the adjustment of the hyper-parameter. Therefore, it is necessary to try various applications of multiple learning algorithms and ANN optimization techniques. Such an approach would help solve problems with a small number of available data, such as the rapidly changing business environment or the current shipping market.

• 생명과학회지
• /
• 제8권1호
• /
• pp.40-50
• /
• 1998

Staphylococuus aureus and Escherichia coli is increasingly responsible for outbreaks of nosocomial infection around the world. Because serious infections due to these organisms currently necessiate use of non-$\beta$-lactam antimicrobial therapy and because strains is ofen resistant to many antimicrobial agents, infections with this organism are difficult to treat. Isolated strains from post operaton wounds of PNU hospital patient were tested for the antimicrobial susceptibility, resistant pattern and combined action to the 6 antibiotics. The minimal inhibitory concentraction of each antibiotic anc antibiotics combining in various ratios were measured by checkerboard dilution method. the synergism was determined through calculating the fractional inhibitory concentraction index (FICI). In case of S. aureus, 15 strains was shown to be highly sensitive to streptomycin and 13 strains to cephalothin. In case of E. coli, it is excellent senstitive 16 strains, sensitive 4 strains on cefoperazone, as like S. aureus, and thus the sensitive is most to be 66%. As the result of gaining MIC from S. aureus upon agar dilution method, MIC$_{50}$ was 8$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml and thus the streptomycine is shown to be lowest. In case of E, coli, S. MIC$_{50}$ was 4$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml, in streptomycin and thus is shown to be lower than S. aureus. As the result of comparing the resistance aspect of combining the antibiotics on S. aureus and E. coli, the resistant strain can be known to be reduced to the large range more than each 40% than combining with only aminoglycoside-series or cephalosporine-series. As the result of combining aminoglycoside-series, streptomycin and cephalothin or cefuroxime sensitive to S. aureus and E. coli in the above mentioned results, the increase or imporovement of effect is over 73% and 80%, respectively, thus the case od combining 2 antibiotics is shown to be better in the effect. Isolated strains from operating wounds were for the antimicrobial susceptibility. In case of S. aureus 15 strains was shown to be sensitive very much on streptomycin. In case of E. coli it is excellent sensitive 16 strains. As the results of combining aminoglycosides-series, streptomycin and cephalosporine series, cephalothin and cefuroxime, the increase or improvement of effect is over 73%, thus case of combining 2 antibiotics is shown to be better in the effect.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제49권1호
• /
• pp.2-12
• /
• 2023

The current study aimed to explore the types and frequencies of uncommon complications associated with third molar extractions based on a scoping review of case reports and case series. The study used an electronic literature search based on PubMed and Embase up to March 31, 2020, with an update performed on October 22, 2021. Any case reports and case series that reported complications associated with third molar extractions were included. The types of complications were grouped and the main symptoms of each type of complication were summarized. A total of 51 types of uncommon complications were identified in 248 patients from 186 studies. Most types of complications were post-operative. In the craniofacial and cervical regions, the most frequent complications included iatrogenic displacement of the molars or root fragments in the craniofacial area, late mandibular fracture, and subcutaneous emphysema. In other regions, the most frequent complications include pneumomediastinum, pneumorrhachis, pneumothorax, and pneumopericardium. Of the patients, 37 patients had life-threatening uncommon complications and 20 patients had long-term/irreversible uncommon complications associated with third molar extractions. In conclusion, a variety of uncommon complications associated with third molar extractions were identified. Most complications occurred in the craniofacial and cervical regions and were mild and transient.

• 대한조선학회논문집
• /
• 제32권2호
• /
• pp.93-102
• /
• 1995

2개의 직렬 흑은 병렬로 원공이 배치된 $[0^{\circ}/45^{\circ}/90^{\circ}/-45^{\circ}]_s$ 복합적층판에 대하여 기계적 접합부의 강도 및 파손양상을 알아보고, 기하학적 형상을 변화시키면서, 파손강도 및 파손모드에 대하여 FEM으로 예측한 값과 실험결과로 얻은 자료, 그리고 실험식으로 계산한 값을 각각 비교 검토했다. 두 직렬 원공이 있는 적층판의 기계적 접합에 있어, $W/d{\geq}4.0$과 $E/d{\geq}3.0$의 기하학적 범위에서 Full bearing 강도를 얻을 수 있다. 두개의 병렬 및 직렬원공인 경우, $G_h{\geq}3.0d$(원공간의 수평거리가 직경의 3배 이상)이고, $G_v{\geq}3.0d$(원공간의 수직거리가 직경의 3배 이상)이면 원공간의 상호간섭효과는 작게 되어, 각각의 원공들을 독립적으로 취급할 수 있다. 복합재료의 특성파악에 알맞은 비파괴 시험법인 AE을 이용했고 미시적 구조를 관찰하기 위해 주사형 전자현미경(SEM)으로 파단면을 촬영하여 탐색하였다.