• Journal of Ecology and Environment
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• 제35권2호
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• pp.91-98
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• 2012

This study was performed in order to suggest the possibility of tree species classification using high-resolution QuickBird-2 images spectral characteristics comparison(digital numbers [DNs]) of tree species, tree species classification, and accuracy verification. In October 2010, the tree species of three conifers and eight broad-leaved trees were examined in the areas studied. The spectral characteristics of each species were observed, and the study area was classified by image classification. The results were as follows: Panchromatic and multi-spectral band 4 was found to be useful for tree species classification. DNs values of conifers were lower than broad-leaved trees. Vegetation indices such as normalized difference vegetation index (NDVI), soil brightness index (SBI), green vegetation index (GVI) and Biband showed similar patterns to band 4 and panchromatic (PAN); Tukey's multiple comparison test was significant among tree species. However, tree species within the same genus, such as $Pinus$ $densiflora-P.$ $rigida$ and $Quercus$ $mongolica-Q.$ $serrata$, showed similar DNs patterns and, therefore, supervised classification results were difficult to distinguish within the same genus; Random selection of validation pixels showed an overall classification accuracy of 74.1% and Kappa coefficient was 70.6%. The classification accuracy of $Pterocarya$ $stenoptera$, 89.5%, was found to be the highest. The classification accuracy of broad-leaved trees was lower than expected, ranging from 47.9% to 88.9%. $P.$ $densiflora-P.$ $rigida$ and $Q.$ $mongolica-Q.$ $serrata$ were classified as the same species because they did not show significant differences in terms of spectral patterns.

• Journal of Preventive Medicine and Public Health
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• 제48권5호
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• pp.239-248
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• 2015

Objectives: The purpose of this study was to assess the inter-rater reliability and intra-rater reliability of medical record review for the detection of hospital adverse events. Methods: We conducted two stages retrospective medical records review of a random sample of 96 patients from one acute-care general hospital. The first stage was an explicit patient record review by two nurses to detect the presence of 41 screening criteria (SC). The second stage was an implicit structured review by two physicians to identify the occurrence of adverse events from the positive cases on the SC. The inter-rater reliability of two nurses and that of two physicians were assessed. The intra-rater reliability was also evaluated by using test-retest method at approximately two weeks later. Results: In 84.2% of the patient medical records, the nurses agreed as to the necessity for the second stage review (kappa, 0.68; 95% confidence interval [CI], 0.54 to 0.83). In 93.0% of the patient medical records screened by nurses, the physicians agreed about the absence or presence of adverse events (kappa, 0.71; 95% CI, 0.44 to 0.97). When assessing intra-rater reliability, the kappa indices of two nurses were 0.54 (95% CI, 0.31 to 0.77) and 0.67 (95% CI, 0.47 to 0.87), whereas those of two physicians were 0.87 (95% CI, 0.62 to 1.00) and 0.37 (95% CI, -0.16 to 0.89). Conclusions: In this study, the medical record review for detecting adverse events showed intermediate to good level of inter-rater and intra-rater reliability. Well organized training program for reviewers and clearly defining SC are required to get more reliable results in the hospital adverse event study.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.147-154
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• 2007

This paper describes a 'gyro-mouse', which provides a new human-computer interface (HCI) for persons who are disabled in their upper extremities, for handling the mouse-click and mouse-move function. We adopted the artificial neural network to recognize a quick-nodding pattern of the disabled person as the gyro-mouse click. The performance of our gyro-mouse was evaluated by three indices that include 'click recognition rate', 'error in cursor position control', and 'click rate per minute' on a target box appearing at random positions. Although it turned out that the average error in cursor positioning control was 1.4-1.5 times larger than that of optical mouse control, and the average click rate per minute was 40% of the optical mouse, the overall click recognition rate was 93%. Moreover, the click rate per minute increased from 35.2% to 44% with repetitive trials. Hence, our suggested gyro-mouse system can be used to provide a new user interface tool especially for those persons who do not have full use of their upper extremities.

• 한국수산과학회지
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• 제53권5호
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• pp.699-706
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• 2020

Predictive models in food microbiology are used for predicting microbial growth or death rates using mathematical and statistical tools considering the intrinsic and extrinsic factors of food. This study developed predictive growth models for Bacillus cereus on dried laver Pyropia pseudolinearis stored at different temperatures (5, 10, 15, 20, and 25℃). Primary models developed for specific growth rate (SGR), lag time (LT), and maximum population density (MPD) indicated a good fit (R²≥0.98) with the Gompertz equation. The SGR values were 0.03, 0.08, and 0.12, and the LT values were 12.64, 4.01, and 2.17 h, at the storage temperatures of 15, 20, and 25℃, respectively. Secondary models for the same parameters were determined via nonlinear regression as follows: SGR=0.0228-0.0069*T₁+0.0005*T₁²; LT=113.0685-9.6256*T₁+0.2079*T₁²; MPD=1.6630+0.4284*T₁-0.0080*T₁² (where T₁ is the storage temperature). The appropriateness of the secondary models was validated using statistical indices, such as mean squared error (MSE<0.01), bias factor (0.99≤B_f≤1.07), and accuracy factor (1.01≤A_f≤1.14). External validation was performed at three random temperatures, and the results were consistent with each other. Thus, these models may be useful for predicting the growth of B. cereus on dried laver.

• Korean Journal of Mathematics
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• 제12권1호
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• pp.15-22
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• 2004

In this paper we establish some recurrence relations satisfied by quotient moments of upper record values from the power distribution. Let {$X_n$, $n{\geq}1$} be a sequence of independent an identically distributed random variables with a common continuous distribution function(cdf) $F(x)$ and probability density function(pdf) $f(x)$. Let $Y_n=max\{X_1,X_2,{\cdots},X_n\}$ for $n{\geq}1$. We say $X_j$ is an upper record value of {$X_n$, $n{\geq}1$}, if $Y_j$ > $Y_{j-1}$, $j$ > 1. The indices at which the upper record values occur are given by the record times {$u(n)$}, $n{\geq}1$, where $u(n)=min\{j{\mid}j>u(n-1),X_j>X_{u(n-1)},n{\geq}2\}$ and $u(1)=1$. Suppose $X{\in}POW(0,1,{\theta})$ then $$E\left(\frac{X^r_{u(m)}}{X^{s+1}_{u(n)}}\right)=\frac{\theta}{s}E\left(\frac{X^r_{u(m)}}{X^s_{u(n-1)}}\right)+\frac{(s-\theta)}{s}E\left(\frac{X^r_{u(m)}}{X^s_{u(n)}\right)\;and\;E\left(\frac{X^{r+1}_{u(m)}}{X^s_{u(n)}}\right)=\frac{\theta}{n+1}\left[E\left(\frac{X^{r+1}_{u(m-1)}}{X^s_{u(n+1)}}\right)-E\left(\frac{X^{r+1}_{u(m)}}{X^s_{u(n-1)}}\right)+\frac{r+1}{\theta}E\left(\frac{X^r_{u(m)}}{X^s_{u(n)}}\right)\right]$$.

• 생명과학회지
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• 제8권6호
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• pp.687-694
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• 1998

한국 남부지방의 매화노루발(Chimaphila japonica Miq.)의 유전적 다양성 및 집단구조를 조사하기 위해 전기영동을 실시하였다. 집단내 다형현상을 나타내는 대립유전자는 48.7%였다. 종 및 집단 수준에서 유전적 다양도는 각각 0.278, 0.222로 나타났고, 집단간 분화 정도는 비교적 낮았다( $G_{ST}$ =0.079). 조사한 일곱 집단내 자가 수분계수는 0.355였다. $G_{ST}$ 로부터 간접적으로 구한 세대당 집단간 이동개체수는 약간 높게 나타나므로 한반도 남부 지방의 집단간 유전자 이동이 보편적으로 이루어 지고 있음을 시사한다 (Nm=2.61). 고정지수 분석에 의하면 이형접합자의 부족이 여러 집단 및 대립유전자좌위에서 나타났다. 이 종에서 유전적 다양도가 고양된 주된 이유는 광범위한 분포, 다년생, 영양번식, 곤충에 의한 타가수분, 그리고 바람에 의한 화분분산이 빈번하게 이루어진 것으로 사료된다.

• 한국통신학회논문지
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• 제34권1C호
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• pp.28-36
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• 2009

Hellman에 의해서 처음 제시된 TMTO (time memory trade-o런 암호 해독 방법은 블록 암호, 스트림 암호, 그리고 해쉬 함수와 같은 일반적인 암호 시스템에 광범위하게 적용된다. 이 논문에서는 TMTO 암호 해독 방법에서 선계산 단계에서 테이블을 저장하기 위해 필요한 저장 공간을 감소시킬 수 있는 방법을 제안한다. 시작점을 의사난수 수열군 통해서 생성하고 시작점의 실제 값 대신 난수 수열 군에서 몇 번째로 취한 값인지에 대한 색인을 저장하는 방식으로 시작점을 저장하기 위해 필요한 메모리 용량을 줄일 수 있다. 이 논문에서는 이 방법을 사용하면 키의 길이가 126 비트일 경우에 시작점을 저장하기 위해 필요한 메모리의 양을 10% 이하로 줄이는 것도 가능하다는 것을 보일 것이다. 이에 대한 비용으로 온라인 단계에서의 탐색 시간이 조금 더 늘어나지만 메모리가 시간에 비해서 더 비싼 자원이기 때문에 필요한 메모리 용량이 감소하게 되면 공격의 실현가능성이 더욱 커지게 된다.

• 생명과학회지
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• 제16권1호
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• pp.64-70
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• 2006

한국내 주걱노루발의 유전적 다양성과 집단구조를 평가하기 위해 전분 젤 전기영동을 사용하였다. 효소내 다형현상을 나타내는 대립유전자좌위는 $57.1\%$였다. 종 수준(Hes = 0.149)과 집단 수준(Hep = 0.134)에서 유전적 다양도는 유사한 생활사를 가진 초본류의 평균값에 비해 높았다. 반면에 집단간 분화정도는 비교적 낮았다 $(G_{ST}=0.082)$. 열 두 집단내 임의교배에서 편차는 0.298이었다. 간접적으로 평가한 세대당 이주하는 개체수(Nm = 2.81)는 이 종의 한국 집단내 보통 수준을 유지하고 있었다. 고정지수 분석 결판 많은 집단과 대립유전자좌위에서 이형접합체의 결핍이 있었다. 이는 주걱노루발에서 가근의 번식능력과 한국내 조사된 주걱노루발 집단의 크기 감소에 기인한다.

• Safety and Health at Work
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• 제9권3호
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• pp.334-338
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• 2018

Background: With global changes in the current state of work and employment, the role of health-adverse psychosocial work environments has received increasing attention in developed as well as in rapidly developing countries. Thus, there is a need to apply valid measurement tools for monitoring and preventive purposes. This study aims to examine the factorial structure and psychometric properties of the Persian version of the effort-reward imbalance (ERI) questionnaire, assessing one of the internationally leading concepts of stressful work. Methods: This descriptive cross-sectional study of a random sample of 202 white collar employees in an industrial company in Iran analyzes the ERI scales by exploratory and confirmatory factor analysis. Moreover, aspects of construct and criterion validity are tested. To this end, correlations of ERI scales with subscales of organizational injustice, a complementary work stress model, and also the correlations of ERI scales with a questionnaire assessing psychosomatic symptoms are performed. Results: Internal consistency of the three ERI scales was satisfactoryy (Cronbach ${\alpha}$ effort: 0.76, reward: 0.79, overcommitment: 0.75). Fit indices of confirmatory factor analsis pointed to an adequate representation of the theoretical construct (e.g., adjusted goodness of fit index (AGFI): 0.73, goodness of fit index (GFI): 0.78). Negative correlations with subscales of organizational injustice supported the notion of construct validity of the ERI scales, and positive correlations of ERI scales with psychosomatic symptoms indicated preliminary criterion validity. Conclusion: The Persian version of the ERI questionnaire has acceptable psychometric properties and can be used as a valid instrument in research on this topic.

• 대한원격탐사학회지
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• 제26권5호
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• pp.537-547
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• 2010

FPAR는 다양한 육상 생태계 모텔에서 중요한 입력변수로 사용된다. 이 때문에 다양한 global product의 형태로 제공되고 있다. 하지만 한반도를 영역으로 하는 연구에 이를 바로 적용 시 오차가 발생할 수 있고, 이것은 위성자료를 이용한 지면 정보 산출에 있어서 직접적인 오차요인이 된다. 따라서 본 연구에서는 Terra/MODIS와 SPOT/VEGETATION 그리고 ECOCLIMAP 자료를 이용해 한반도에 최적화된 FPAR를 산출 하였고, 또한 기존에 사용하였던 LAI와의 관계식을 사용하지 않고, SPOT/VGT NDVI 로부터 계산된 FVC (Fraction Vegetation Cover)를 직접 이용하여 FPAR를 산출 하였다. 이를 위해 식생지수의 선형/비선형 관계를 이용하여 구하는 경험적인 방법을 적용하여 회귀분석을 수행한 결과 cropland와 forest에서 각각 결정계수 (Coefficient of Determination, $R^2$)가 0.9039. 0.7901으로 정확도가 높은 관계식을 도출해내었다. 최종적으로 Reference FPAR 자료와의 비교 분석을 통해 본 연구에서 산출된 FPAR가 전반적인 패턴을 잘 표현하면서 불규칙하게 발생하던 노이즈 또한 보정된 것을 확인 할 수 있었다. 이렇게 한반도에 최적화된 입력변수의 사용은 산출물의 정확도뿐만 아니라 연구의 질 향상에도 도움을 줄 것으로 사료된다.