• 한국컴퓨터정보학회논문지
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• 제19권9호
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• pp.161-168
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• 2014

공항에 불규칙한 시간간격으로 접근하는 항공기들을 최소의 비용으로 착륙시키는 항공기 착륙 문제 (ALP)는 최적 해를 구하기 어려워 다양한 메타휴리스틱 방법들이 제안되고 있다. 본 논문에서는 ALP에 대해 O(nlog n)의 다항시간으로 최적 해를 구하는 휴리스틱 알고리즘을 제안한다. 제안된 알고리즘은 착륙 목표시간 오름차순으로 정렬시키고, 항공기들 간의 분리 시간과 착륙 비용을 고려하여 착륙순서를 변경시킨 최적화 과정을 수행하는 방법을 적용하였다. ALP에 대한 예제 데이터인 Airland1 ~ Airland8에 대해 소요비용이 0이 되는 활주로 개수 m까지 25개 데이터를 실험한 결과 모든 데이터에 대해 최적 해를 구하였다. 특히, Airland8의 m = 1 데이터에 대해서는 기존에 알려진 최적 해를 개선하였다.

• 운동영양학회지
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• 제25권1호
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• pp.7-15
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• 2021

[Purpose] Sodium bicarbonate shows ergogenic potential in physical exercise and sports activities, although there is no strong evidence which performance markers show the greatest benefit from this supplement. This study evaluated the effects of sodium bicarbonate supplementation on time trial performance and time to exhaustion in athletes and sports practitioners. [Methods] A systematic review was conducted using three databases, including 17 clinical trials. Among these clinical trials, 11 were considered eligible for the meta-analysis according to the criteria for the assessment of methodological quality using the PEDro Scale. Time to exhaustion was assessed in six studies, while time trial performance was evaluated in five studies. [Results] A significant beneficial effect of supplementation on time to exhaustion was found in a random effects model (1.48; 95% confidence interval [CI], 0.49 to 2.48). There was no significant effect of supplementation on time trial performance in a fixed effects model (slope = -0.75; 95% CI, -2.04 to 0.55) relative to a placebo group. [Conclusion] Sodium bicarbonate has the potential to improve sports performance in general, especially in terms of time to exhaustion.

• 대한전자공학회논문지TC
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• 제44권1호
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• pp.113-122
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• 2007

이동 통신망에서 시간 기반 및 이동 기반의 위치 갱신 방법을 결합한 혼합형 위치 갱신 방법을 제안한다. 제안된 방법에서는 이동단말이 셀 경계를 n번 이동한 후 T의 시간이 지난 후에 자신의 위치를 갱신한다. 또한 사용자의 이동특성을 다중 상태의 지수분포 셀 체류시간 모델로 정의하여, 제안된 혼합형 위치 갱신 방법을 적용한다. 제안된 혼합형 위치 갱신 방법 및 다중 상태의 지수 분포 셀 체류시간 모델에 대한 수식적인 분석을 수행하였으며, 이를 모의 실험 분석을 통하여 검증하였다. 수식적인 분석과 모의 실험 분석의 결과, 다중 상태의 이동성 모델의 경우 제안하는 혼합형 위치 갱신 방법이 시간 기반의 위치 갱신 방법이나 이동 기반의 위치 갱신 방법 보다 뛰어남을 보여주며, 따라서 시간에 따라 수시로 변하는 이동성을 갖는 사용자에게 혼합형 위치 갱신 방법이 효과적으로 적용될 수 있음을 알 수 있었다.

• 한국간담췌외과학회지
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• 제28권2호
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• pp.115-124
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• 2024

To compare the outcomes of low central venous pressure (CVP) to standard CVP during laparoscopic liver resection. The study design was a systematic review following the PRISMA statement standards. The available literature was searched to identify all studies comparing low CVP with standard CVP in patients undergoing laparoscopic liver resection. The outcomes included intraoperative blood loss (primary outcome), need for blood transfusion, mean arterial pressure, operative time, Pringle time, and total complications. Random-effects modelling was applied for analyses. Type I and type II errors were assessed by trial sequential analysis (TSA). A total of 8 studies including 682 patients were included (low CVP group, 342; standard CVP group, 340). Low CVP reduced intraoperative blood loss during laparoscopic liver resection (mean difference [MD], -193.49 mL; 95% confidence interval [CI], -339.86 to -47.12; p = 0.01). However, low CVP did not have any effect on blood transfusion requirement (odds ratio [OR], 0.54; 95% CI, 0.28-1.03; p = 0.06), mean arterial pressure (MD, -1.55 mm Hg; 95% CI, -3.85-0.75; p = 0.19), Pringle time (MD, -0.99 minutes; 95% CI, -5.82-3.84; p = 0.69), operative time (MD, -16.38 minutes; 95% CI, -36.68-3.39; p = 0.11), or total complications (OR, 1.92; 95% CI, 0.97-3.80; p = 0.06). TSA suggested that the meta-analysis for the primary outcome was not subject to type I or II errors. Low CVP may reduce intraoperative blood loss during laparoscopic liver resection (moderate certainty); however, this may not translate into shorter operative time, shorter Pringle time, or less need for blood transfusion. Randomized controlled trials with larger sample sizes will provide more robust evidence.

• 제어로봇시스템학회논문지
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• 제19권5호
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• pp.481-487
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• 2013

This paper presents an FIR (Finite Impulse Response) fixed-interval smoothing filter for fast and exact estimating state variables of a discrete nonlinear system with modeling uncertainty. Conventional IIR (Infinite Impulse Response) filter and smoothing filter can estimate state variables of a system with an exact model when the system is observable. When there is an uncertainty in the system model, however, conventional IIR filter and smoothing filter may cause large errors because the filters cannot estimate the state variables corresponding to the uncertain model exactly. To solve this problem, FIR filters that have fast estimation properties and have robustness to the modeling uncertainty have been developed. However, there is time-delay estimation phenomenon in the FIR filter. The FIR smoothing filter proposed in this paper makes up for the drawbacks of the IIR filter, IIR smoothing filter, and FIR filter. Therefore, the FIR smoothing filter has good estimation performance irrespective of modeling uncertainty. The proposed FIR smoothing filter is applied to the integrated navigation system composed of a magnetic compass based DR (Dead Reckoning) and a GPS (Global Positioning System) receiver. Even when the magnetic compass error that changes largely as the surrounding magnetic field is modeled as a random constant, it is shown that the FIR smoothing filter can estimate the varying magnetic compass error fast and exactly with simulation results.

• Physical Therapy Rehabilitation Science
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• 제13권2호
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• pp.143-151
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• 2024

Objective: This study aims to assess the test-retest reproducibility of the Short Form Berg Balance Scale (SF-BBS) and the Short Form Postural Assessment Scale for Stroke (SF-PASS) among chronic stroke survivors, focusing on their reliability for consistent measurements over time. Design: A cross-sectional study design Methods: Thirty chronic stroke survivors participated in this study, undergoing evaluations with SF-BBS and SF-PASS scales at two different points, separated by a seven-day interval. The analysis focused on test-retest reliability, employing statistical measures such as the Intra-Class Coefficient (ICC_2,1), Standard Error of Measurement (SEM), Minimal Detectable Change (MDC), and MDC%, the Bland-Altman plot to assess the limits of agreement and the extent of random measurement error. Results: The study found notable test-retest reproducibility for both SF-BBS and SF-PASS, with ICC values demonstrating strong reliability (0.932 to 0.941, with a confidence interval of 0.889 to 0.973). SEM values for SF-BBS and SF-PASS were reported as 1.34 and 0.61, respectively, indicating low measurement error. MDC values of 3.71 for SF-BBS and 1.69 for SF-PASS suggest that the scales have an acceptable level of sensitivity to change, with reliability metrics falling below 20% of the maximum possible score. Conclusions: The findings suggest that both SF-BBS and SF-PASS exhibit high intra-class correlation coefficients, indicating strong test-retest reliability. The SEM and MDC values further support the scales' reproducibility and reliability as tools for evaluating mobility and dynamic balance in chronic stroke survivors. Therefore, these scales are recommended for clinical use in this population, providing reliable measures for assessing progress in rehabilitation.

• 대한간호학회지
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• 제4권1호
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• pp.95-106
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• 1974

The Purpose of this study was to observe the body temperature changes of newborn infants in general crib and electric heat crib after birth for the period required to reach the optimum body temperature. Forty-seven newborn infants who were delivered at Seoul National University Hospital during the period from June 12 to September 13, 1973 were chosen as Subjects for this study. The criteria for the choice of subjects were the babies with normal spontaneous delivery; body weight 2.5kg and over at birth; Apgar so ore seven and over and gestation period over thirty-six weeks. Of these subjects, by random sampling thirty-one newborn infants were placed in the general crib and sixteen in the electric-heat crib. The rectal body temperature of these newborn infants were taken and recorded at fifteen-minute interval for the first one hour period after birth, at thirty minute interval for the next two hours and at one hour interval for the remaining period up to eight hours. The results of the study were as follows: 1. The mean body temperature of the newborn infants on admission to nursery ranged from 98.7℉. to 99℉. irrespective of the body weight and the room temperature. 2. There was a significant difference in the body temperature changes of the newborn infants as a total between the general crib and the electric-heat crib from three to eight hours after birth. It was found that the body temperature of the newborn infants in the electric-heat crib was significantly higher than that of the newborn infants in the general crib. 3. In comparison with the body temperature changes of the newborn infants in the general crib, the newborn infants in the electric- heat crib exhibited significantly higher body temperatures in all three body weight groups; from four to eight hours after birth in the 2.5-2.9kg body weight group; from three to seven hours after birth in the 3.0-3.4kg body weight group; from two and half to six hours after birth in the group with body weight over 3.5kg. 4. Time required to reach 98℉. of body temperature was four hours in the 3.5-2.9kg body weight group, three hours in the 3.0-3.4kg. body weight group and two and half hours in the group with body weight over 3.5kg in the electric- heat crib. In the general crib, it took over eight hours in the 2.5-2.9kg body weight group and five hors in both the 3.0-3.4kg and over 3.5kg body weight group to reach 98℉ of body temperature. 5. The lowest mean body temperature of newborn infants in both general and electric- heat crib appeared in forty-five minute after birth and the temperature ranged from 96.4℉ to 96.5℉. 6. The mean body temperature of the newborn infants in the general crib was increased as the room temperature. 7. The body weight, the room temperature and the time elapsed after birth fore proved to be significant factors influencing the body temperature changes of newborn infants. From tile above results, the three hypotheses were positively accepted.

• 한국항해항만학회지
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• 제40권2호
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• pp.83-87
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• 2016

The maritime industry is expanding at an alarming rate hence there is a perpetual need to improve situation awareness in the maritime environment using new and emerging technology. Tracking is one of the numerous ways of enhancing situation awareness by providing information that may be useful to the operator. The tracking module designed herein comprises determining existing states of high dynamic target warship, state prediction and state compensation due to random noise. This is achieved by first analyzing the process of tracking followed by design of a tracking algorithm that uses ${\alpha}-{\beta}-{\gamma}$ tracking filter under a random noise. The algorithm involves initializing the state parameters which include position, velocity, acceleration and the course. This is then followed by state prediction at each time interval. A weighted difference of the observed and predicted state values at the $n^{th}$ observation is added to the predicted state to obtain the smoothed (filtered) state. This estimation is subsequently employed to determine the predicted state in the next radar scan. The filtering coefficients ${\alpha}$, ${\beta}$ and ${\gamma}$ are determined from a pre-determined value of the damping parameter, ${\xi}$. The smoothed, predicted and the observed positions are used to compute the twice distance root mean square (2drms) error as a measure of the ability of the tracking module to manage the noise to acceptable levels.

• Communications for Statistical Applications and Methods
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• 제15권4호
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• pp.563-585
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• 2008

본 연구는 다양하고 복잡해지는 파생상품 추세에 상응하는 적절한 가치평가에 대한 연구의 필요성을 인지하고 가격 및 민감도 평가에 있어서 속도와 정확도를 향상시키는데 그 의의를 두고자 한다. 몬테카를로 시뮬레이션에서 의사난수 대신 저불일치수열인준난수를 이용하면 시행횟수의 감소와 정확도 개선이 가능한데, 미국형 옵션이나 경로의존형 상품 등 다차원의 난수가 필요할 경우 기존의 준난수를 사용하면 상관관계가 증가하는 문제로 적용에 한계가 있다. 이런 단점을 보완하기 위해 문제를 발생시키는 차원의 난수를 제외시켜 상관계수를 특정값 이하로 제어하는 새로운 방법을 고안하여 다차원 상품에 적용이 가능토록 하였고 미국형 풋옵션에 적용하여 새로운 방법의 유용성을 검증하였다. 또한, 몬테카를로 시뮬레이션에서 민감도 계산방법으로 우도비율법과 경로의존형 근사방법을 사용하면 속도 및 정확도가 개선됨을 보인다. 이러한 결과는 최근 시장의 추세인 기초자산이나 위험요소가 여러 개인 경우 그리고 경로의존형 및 조기상환형 상품 등에 적용 가능토록하여 몬테카를로 시뮬레이션 방법에 있어 가장 큰 단점으로 지적되는 수행시간을 단축시키고 민감도 계산의 오차를 줄여줌을 보여준다. 또한, 2개 이하의 기초자산으로 이루어진 파생상품의 가치 및 민감도 평가에 가장 효율적인 수치해석적 방법론으로 알려져 있는 유한차분법의 적용시 격자생성구간의 설정이 매우 중요하다는 사실을 비대칭 나비형스프레드에 적용하여 실증적으로 보인다.

• The Journal of Advanced Prosthodontics
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• 제8권6호
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• pp.457-464
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• 2016

PURPOSE. The aim of this study was to determine whether two methods of documentation, print and electronic forms, for the assessment of patient-reported outcomes (PRO) in complete denture wearers provide comparable results. The study also quantified the time needed for filling the forms by each method. MATERIALS AND METHODS. Thirty participants enrolled in a university clinic answered two forms (a questionnaire for denture satisfaction and OHIP-EDENT). They provided answers with two application methods in a random order, with a one-month interval between them: (1) electronic forms on a tablet computer; and (2) print forms. The methods were compared in terms of mean results, correlation/agreement, internal consistency, and spent time. RESULTS. Mean results for both methods were similar for each denture satisfaction item (100-mm VAS) and OHIP-EDENT summary score. Both questionnaires presented good internal consistency regardless of the application method (Cronbach's ${\alpha}=0.86$ or higher). Correlation and agreement between the methods regarding specific items was at least moderate for the majority of cases. Mean time for the electronic and print forms were 9.2 and 8.5 minutes, respectively (paired t test, P=.06, non-significant). CONCLUSION. The electronic method is comparable to print forms for the assessment of important PRO of prosthetic treatment for edentulism, considering the results and time needed. Findings suggest the viability of replacing print forms with a tablet for applying the tested inventories in clinical trials.