• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.5
• /
• pp.1601-1607
• /
• 2010

This paper presents FMEA (Failure Mode Effect Analysis) for maintenance of mail sorting machine which is for automatic sorting of mail. We suggest the update method of regular diagnosis item and period for maintenance of mail sorting machine using the risk priority number which is calculated by severity, occurrence, and detection of failure mode of mail sorting machine, and shows FMEA adoption example of letter sorting machine. This paper also describes the current maintenance system and status of mail sorting machine in the domestic postal logistics environment, and FMEA adoption step. The proposed maintenance using FMEA will be adapted for more easy and efficiency maintenance of mail sorting machine.

• The Journal of Fisheries Business Administration
• /
• v.49 no.4
• /
• pp.19-36
• /
• 2018

Overstock in aquaculture is a matter of concern in aquaculture management. To sort fish based on fingerling size in case of overstocking is an important problem in aquaculture farm. This study aims to determine the amount of fry overstock and sorting time in aquaculture farm. This study builds a mathematical model that finds the value of decision variables to optimize objective function summing up the fingerling purchasing cost, aquaculture farm operating cost and feeding cost under mortality and farming period constraints. The proposed mathematical model involves following biological and economical variables and coefficients: (1) number of fingerlings, (2) sorting time, (3) fish growth rate and variation, (4) mortality, (5) price of a fry (6) feeding cost, and (7) possible sorting periods. Numerical simulation is presented herein. The objective of numerical simulation is to provide decision makers to analyse and comprehend the proposed model. When extensive biological data about growth function of fry becomes available, the proposed model can be widely applicable to real aquaculture farms.

• Journal of the Ergonomics Society of Korea
• /
• v.23 no.4
• /
• pp.35-43
• /
• 2004

The purpose of this study is to redesign a letter sorting station and to present the optimal work-space through the ergonomic analysis of the sorting station for reducing the 'Work-Related MusculoSkeletal Disorders(WMSDs)'. We surveyed the work environment in terms of the reason causing WMSDs. According to the survey results, Deltoid on the arm, Trapezius on the shoulder and Erector Spinae on the waist are most frequent attacking parts. Accordingly, We classified sorting stations by the horizontal work-space(Level 1, Level 2, Level 3) and the vertical work space(Level 1, Level 2) based on the criteria of ergonomic optimal work-space. In addition we improved the sorting station through investigation and analysis of the work-load regard the each defined work-space. In order to analyze the effect of the horizontal and vertical work-space, subjects carried out simulated sorting tasks. Each level(Level 1, Level 2, Level3) of the horizontal work-space is significant regarding each muscles(the shoulder, arm and waist), and each level(Level 1, Level 2) of the vertical work-space is significant regarding the arm and waist, but not shoulder. Finally, we founded the difference of work-load according to the work-spaces. Then, it is necessary to improve the work-space causing the high work-load(Level 3 of the horizontal work-space). Then, this study presented the specification of a sorting station which is suitable to the korean body size, and constructed the 3D shaped model of the stations by the ergonomic analysis.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.6
• /
• pp.1839-1845
• /
• 2016

Detecting remote targets is important to active protection system (APS) or infrared search and track (IRST) applications. In normal situation, the well-known constant false alarm rate (CFAR) detector works properly. However, decoys in APS or closely spaced targets in IRST degrade the detection capability by increasing background noise level in the CFAR detector. This paper presents a context aware CFAR detector by the intensity sorting and selection of background region to reduce the effect of neighboring targets that lead to incorrect estimation of background statistics. The existence of neighboring targets can be recognized by intensity sorting where neighboring targets usually show highest ranks. The proposed background statistics (mean, standard deviation) estimation method from median local pixels can be aware of the background context and reduce the effects of the neighboring targets, which increase the signal-to-clutter ratio. The experimental results on the synthetic APS sequence, real adjacent target sequence, and remote pedestrian sequence validated that the proposed method produced an enhanced detection rate with the same false alarm rate compared with the hysteresis-CFAR (H-CFAR) detection.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.7B
• /
• pp.686-694
• /
• 2002

In this paper, we introduce an improved sorting method of the IGIC(Improved initial stage Grouping Interference Canceller) system for advanced BER(Bit Error Rate) performance in DS-CDMA. Among non liner Interference Cancellers, the PIC(Parallel IC) with advanced initial stage by sorting method has the name of the IGIC(Improved initial stage Grouping Interference Canceller) system. In this system, All group are shared with the same number of users. But, if each group are divided the same users, so that difference of the signals strength appeared greatly in the same group. Up to this time, the weak signals have more effect of the MAI (Multiple Access Interference) from the strong signals in the same group. The proposed IC (Interference Canceller) to solve those problems has a better performance by using improved sorting method from IGIC system. A new sorting method is the technique that the strength of signals would be liked in the same group. So, the MAI is reduced as difference of signal strength minimize. Analysis of performance assayed to make comparison with other non liner interference canceller when power controlled and not one.

• Journal of Preventive Medicine and Public Health
• /
• v.6 no.1
• /
• pp.77-79
• /
• 1973

The Mechanism for sorting out the covariance effect is known as the covariance analysis. The sorting out of regression and correlation effect is an obvious application of the covariance analysis. The result of Do population by age groups (15 ages interval) from 1966 Census and from 1970 Census has been applied to analyzing covariability by the analysis of covariance. The results are as follows. (1) The signicance of the regression of 1970 population on 1966 population is assured as F=116.5 (2) There is a significant difference between mean of each age group. (F=88.1) (3) There is very little evidence of significant heterogeneity of regression between age groups. (F=0.72)

• Journal of Distribution Science
• /
• v.21 no.8
• /
• pp.35-45
• /
• 2023

Purpose: This paper (1) identifies the factors that affect people's changing habits towards waste sorting, (2) evaluates the benefits of waste sorting to the environment and (3) designs communication strategies to change people's behavior and habits in sorting plastic waste in Ho Chi Mnh City, Vietnam. Research design, data and methodology: Using the data from 309 people that are living in Ho Chi Minh City and Structural Equation Modeling (SEM), to evaluate variables and test the hypotheses. Results: Research results show that attitudes, subjective standards, behavioral control, and facilities affect people's intention to classify plastic waste. We find that environmental concerns greatly influence people's attitudes. In contrast, environmental concerns have a relatively weaker effect on people's degree of behavioral control. Conclusion: Environmental protection is a matter of concern in the world. In Vietnam, this issue has been institutionalized into law to create a basis for improving the effectiveness of environmental protection activities. This article has some limitations. Firstly, sample is limited to HCMC residents; the study results are not representative of the entire population of Vietnam. This paper is based on cross-sectional data, which is not the best way to establish a causal relationship between the intention to sort plastic waste and its drivers.

• Journal of the Korean Wood Science and Technology
• /
• v.20 no.2
• /
• pp.51-60
• /
• 1992

This study was performed to investigate the effect of green sorting before drying on the high-temperature drying characteristics of southern yellow pine dimension lumber(2"${\times}$6"${\times}$12'). To test the advantages of weight sorting, green lumber was seperated into heavy(above 55 1b), medium(50-55 1b), and light(below 50 1b)weight classes. Pieces in each weight class were subgrouped into high(above 35%) and low(below 30%) latewood groups. Groups were dried and seperated by a standard commercial high-temperature schedule; dry bulb temperature $245^{\circ}$ F, wet bulb temperature $180^{\circ}$ F, and air velocity 1200fpm. The results obtained were as follows; 1. There was a highly significant correlation between annual rings per inch(X) and percent-latewood(Y). The regression equation was Y=24, 5047+1.3272X. 2. There were highly significant correlations between either annual rings per inch($X_1$) or percent-latewood($X_2$) a.d specific gravity in green wood(Y). Their regression equations were Y=0.4260+0.0081$X_1$ and Y=0.3749+0.0029$X_2$, respectively. 3. Heavier weight charges dried more slowly than lighter weight charges. 4. Board-to-board variation in green or dry moisture content was less for all seperate weight classes than for unseperated control charges. 5. Lower latewood pieces had higher initial moisture content than higher latewood pieces, and then drying time for lower late wood pieces was longer than higher latewood pieces.

• Korean Journal of Child Studies
• /
• v.30 no.1
• /
• pp.127-148
• /
• 2009

This study investigated the effects on task performance of dyad collaboration based on young children's cognitive and social ability. The 108 5-year-old subjects were assigned to a collaborative experimental group, a comparison group working individually in sorting, writing, and making a puzzle, or a control group. Data from before and after measurements on sorting and perspective taking tasks were analyzed by t-test and ANOVA. Results showed that (1) Children working in dyad collaboration obtained significantly more improvement in their performance on both tasks than those working individually. (2) Dyads composed of a child with high level social skill but low level intelligence and a child with low levels of both showed most improvement in performance on the perspective taking task.

• The KSFM Journal of Fluid Machinery
• /
• v.17 no.4
• /
• pp.19-29
• /
• 2014

In addition to the development of micro hydro turbine, the challenge in micro hydro turbine design as sustainable hydro devices is focused on the optimization of turbine runner blade which have decisive effect on the turbine performance to reach higher efficiency. A multi-objective optimization method to optimize the performance of runner blade of propeller turbine for micro turbine has been studied. For the initial design of planar blade cascade, singularity distribution method and the combination of the Bezier curve parametric technology is used. A non-dominated sorting genetic algorithm II(NSGA II) is developed based on the multi-objective optimization design method. The comparision with model test show that the blade charachteristics is optimized by NSGA-II has a good efficiency and load distribution. From model test and scale up calculation, the maximum prototype efficiency of the runner blade reaches as high as 90.87%.