• 보건교육건강증진학회지
• /
• 제24권1호
• /
• pp.17-28
• /
• 2007

Objective: To find the relevant stress factors of male and female employees. Method: The survey was collected from April 7th to May 10th in 2006 by formalized questionnaires targeted on male and female employees. The research used both quota sampling and accidental sampling to collect the data. Results: 1) It was found that relevant factors are related with ages in general traits for male employees and associated with ages, marital status and education level in general traits for female employees. In other words, age is the primary factor for both male and female employees at age 20s, and as the marital status is single and the education level is lower, the stress level is higher for female employees. 2) Occupation is the main relevant stress factor for male employees in employment traits and the period of employment, working hour and wages are relevant stress factors to the level of stress for female employees. That is to say, manufacture related job shows higher level of stress than other jobs for both male and female employees. As period of employment and working hour is shorter and wages are less, it appears to be high stress level for female employees. 3) It presents that stress level is decided based on if he exercises regularly or keeps regular hours for male employees in lifestyle aspect and it also shows drinking is an additional relevant stress factor to conclude the level of stress for female employees. So to speak, as the regular exercise is performed and regular hours are kept, it comes out low level of stress for both. In addition, it shows lower stress level from the group of female employees who do not drink than the other. Conclusion: The research is summarized that no matter what gender you are, both male and female employees should try to have a positive lifestyle. Specially, the research concludes that the regular exercise is the best way to get rid of stress.

• 한국농공학회논문집
• /
• 제50권1호
• /
• pp.85-92
• /
• 2008

This study was carried out to estimate heavy metal loads at plain area of the rural watersheds during farming season in 2006. The experimental area was belonging to Geum River watershed. That was located at the center of South Korea. Water samples were corrected at two kinds of aspects. One is regular sampling(every two month) and the other is irregular sampling(every rainfall event). The result showed that heavy metal properties of regular samples were highest at May and June with lively agricultural activities. Heavy metal concentration of irregular samples was lower than that of regular samples. But the heavy metal loads of irregular samples were high. The correlation between each heavy metals of regular samples was following as Mn-Cd > Mn-Fe > Mn-Al > Fe-Al > Al-Cd. The correlation of irregular samples was following as Fe-AI > Zn-Mn > Fe-Cd > Cd-Al. Loading rates of daily discharge the plain area of designed rural watershed during farming season were Al 3.070 kg/day, Cu 0.526 kg/day, Fe 0.745 kg/day, Zn 0.314 kg/day, Cd 0.010 kg/day, Cr 0.055 kg/day, Mn 0.140 kg/day and Pb 0.098 kg/day. Loading rate of discharge with heavy metals during the survey period was Al(577.23 kg) > Fe(140.08 kg) > Cu(98.93 kg) > Zn(58.99 kg) > Mn(26.34 kg) > Pb(18.51 kg) > Cr(10.34 kg) > Cd(1.93 kg).

• Fisheries and Aquatic Sciences
• /
• 제21권8호
• /
• pp.24.1-24.9
• /
• 2018

The Korean bottom trawl survey has been deployed on a regular basis for about the last decade as part of groundfish stock assessments. The regularity indicates that they sample groundfish once per grid cell whose sides are half of one latitude and that of one longitude, respectively, and whose inside is furthermore divided into nine nested grids. Unless they have a special reason (e.g., running into a rocky bottom), their sample location is at the center grid of the nine nested grids. Given data collected by the survey, we intended to show how to appropriately estimate not only the survey index of a fish stock but also its uncertainty. For the regularity reason, we applied the systematic sampling theory for the above purposes and compared its results with a reference, which was based on the simple random sampling. When using the survey data about 11 fish stocks, collected by the spring and fall surveys in 2014, the survey indices of those stocks estimated under the systematic sampling were overall more precise than those under the simple random sampling. In estimates of the survey indices in number, the standard errors of those estimates under the systematic sampling were reduced from those under the simple random sampling by 0.23~27.44%, while in estimates of the survey indices in weight, they decreased by 0.04~31.97%. In bias of the estimates, the systematic sampling was the same as the simple random sampling. Our paper is first in formally showing how to apply the systematic sampling theory to the actual data collected by the Korean bottom trawl surveys.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권12호
• /
• pp.549-555
• /
• 2002

While the z-transform method is a basic mathematical tool to relate the imput/output signals only at the sampling instants in analyzing and designing sampled-data control systems, the modified z-transform which is a variation of the z-transform is widely used to represent the details of continuous signals between the sampling instants. To relate the modified z-transform to the corresponding regular z-transform, some properties were established regarding the modified z-transform method. This paper will show that these properties, in their current forms, cause come analytic problems, when they are applied to the signals with discontinuities at the sampling instants, which accordingly limit their applications significantly. In this paper, those analytic problems will be investigated, and the theorems of the modified z-transform will be revised by adopting new notations on the z-transform so that those can be correctly interpreted and used without any analytic problems. Also some additional useful schemes of applying the modified z-transform will be developed.

• 천문학회보
• /
• 제36권2호
• /
• pp.81.2-81.2
• /
• 2011

Motivated by recent attempts to derive geomagnetic activity from hourly mean data in long term studies, we test the recursive Kalman filter method to obtain the regular solar variation curve of the geomagnetic field. Using a simple algorithm, we are able to assign a quiet day curve to every day separately, without the need for additional input parameter(s) to define the geomagnetically quiet days. We derive a digital counterpart AhK of the analog range index Ak at the subauroral Sodankyl$\ddot{a}$ station and compare it to the earlier digital estimate Ah and the local Ak index. We find that the new method outperforms the former estimate in every aspect studied and provides a robust, straightforward manner of estimating and verifying the manually scaled Ak index, based on readily available hourly values. The model is independent of sampling; thus, for shorter term studies where high-sampling data are available, more accurate estimates can also be obtained when needed. Therefore, in contrast to other recent approaches, we do not provide a method to quantify irregular activity directly but derive the actual quiet day curves in the traditional manner. In future applications the same algorithm may be used to define a wide variety of geomagnetic indices (such as Ak, Dst, or AE).

• 제어로봇시스템학회논문지
• /
• 제22권9호
• /
• pp.710-715
• /
• 2016

Due to its simplicity and high reliability, the box-counting(BC) method is one of the most frequently used techniques to estimate the fractal dimensions of a binary image with a self-similarity property. The fractal calculation requires data sampling that determines the size of boxes to be sampled from the given image and directly affects the accuracy of the fractal dimension estimation. There are three non-overlapping regular grid methods: geometric-step method, arithmetic-step method and divisor-step method. These methods have some drawbacks when the image size M becomes large. This paper presents a BC algorithm for enhancing the accuracy of the fractal dimension estimation based on a new sampling method. Instead of using the geometric-step method, the new sampling method, called the coverage ratio-step method, selects the number of steps according to the coverage ratio. A set of experiments using well-known fractal images showed that the proposed method outperforms the existing BC method and the triangular BC method.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제8권1호
• /
• pp.17-26
• /
• 2004

Pest monitoring through field surveys and surveillance helps in forecasting the population build up of pest. It reduces the load of pesticides application and forms the basis of Integrated Pest Management in sericulture. Common sampling techniques for quantifying pest populations and damage caused by them are reviewed emphasizing the need for quick and simple sampling methods. Various direct and indirect sampling methods for establishing pest populations are discussed and methods have been discussed to use indirect sampling method under IPM programme in sericulture. The use of pheromone lures and traps forms one of the important ingredients of integrated pest management, which calls for integration of all available methods in a cost effective and environmental friendly manner offering consistent efficacy. Silk-worms feed on the variety of silk host plants and spin cocoons. Each silk host plant is attacked in the field by number of insect pest species. Several pests are common to mulberry, tasar, oak tasar, muga and eri host plant but pest status and seasonal abundance differs from each crop. The key pests are serious perennially occurring persistent species which cause considerable yield loss every year on large areas and require control measure. Regular occurrence of minor pest is noticed but sudden increase in its population is not known. The occasional pests are sporadic but potential causing sufficient damage. Silk losses due to attack of all the pests have not been calculated. However, information on pest biology and ecology, and control practices being practiced is available but the period of outbreak of major pests and predators on silkworms and its host plant needs to be reinvestigated. Pest and predators forecasting based on surveillance information may provide an opportunity to minimize the losses, particularly to reduce expenditure involved in pest management.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제53권5호
• /
• pp.331-337
• /
• 2004

Target motion analysis with a sonar system in general uses a regular sampling time and thus obtains regular target information regardless of the target maneuver status. This often results in overconsumption of the limited sonar resources. We propose two methods of the IMM(interacting Multiple Model) PDAF algorithm for sonar resource management to improve target motion analysis performance and to save sonar resources in this paper. In the first method, two different process noise covariance which are used as mode sets are combined based on probability. In the second method, resource time which are processed from two mode sets is calculated based on probability and then considered as update time at next step. Performance of the proposed algorithms are compared with the other algorithms by a series of Monte Carlo simulation.

• 기본간호학회지
• /
• 제14권4호
• /
• pp.500-506
• /
• 2007

Purpose: This study was conducted to analyze the health concerns, health behavior, and related factors for elders taking part in activities at senior centers. Method: A total of 811 elders were selected through conveniently sampling. Data were collected from November 21, 2006 to December 20, 2006. Data analysis included frequency, t-test, ANOVA, Duncan test, and Stepwise Multiple Regression using SPSS Win 15.0. Results: For health concerns statistically significant differences were found for gender, age, family, pockety money, sleeping time, regular health check-ups, and exercise. For health behavior statistically significant differences were found for gender, age, family, pocket money, religion, medical insurance, perceived health status, sleeping time, regular health check-ups, chronic illness, regular breakfast, exercise, and drinking. Perceived health status was identified as a variable influencing the health behavior. Conclusion: The results suggest that perceived health status can be considered as factor for significant nursing interventions to help single elders and older elders in senior centers.

• 한국보건간호학회지
• /
• 제25권2호
• /
• pp.266-275
• /
• 2011

Purpose: The study investigated the relationship of health behavior with bone mineral density (BMD) for college students. Methods: A descriptive study was done using a convenient sampling of college students (n=116) enrolled in a health-related department. Height, weight, body mass index (BMI), health behaviors recognition of subjective health, smoking, drinking, exercise, food habits, intake of calcium, and family history of fracture were measured. BMD was measured at the right forearm using Hologic lunar duel-energy X-ray absorptiometry. Data were analyzed using descriptive analysis, t-test, ANOVA and multiple linear regression. Results: The prevalence of osteopenia and osteoporosis was 41.4% and 22.4%, respectively. Significant relationships were observed between BMD of right forearm and gender, BMI, subjective health recognition, drinking, and exercise (p<.05). Results of linear regression after adjusted BMD were increased concerning subjective health recognition and regular exercise (p<.05). Conclusions: Subjective health recognition and exercise carries positive effects on BMD. We recommend for college students that healthy behaviors like proper weight, smoking cessation, regular exercise, regular food habits, and health awareness are helpful to BMD.