• Journal of the Ergonomics Society of Korea
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• v.32 no.5
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• pp.413-420
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• 2013

Objective: The objective of this study was to compare one-hand and two-hands lowering activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level. Background: Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lowering tasks using both a one-handed as well as a two-handed lowering technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lowering tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lowering tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 6%, as the workload was increased twice from 7.5kg to 15kg. For the right-hand lowering task, these were increased by the average 17%. For the two-hands lowering tasks, these were increased by the average 14%. Conclusion: Even though the effect of workload on the biomechanical stress for both one-hand and two-hands lowering tasks is not so significant for the workload less than 15kg, it can be claimed that the biomechanical stress for one-hand lowering is greater than for two-hands lowering tasks. Therefore, it can be concluded that asymmetrical lowering posture would give greater influence on the biomechanical stress than the workload effect for one-hand lowering activity. Application: The result of this study may be used to provide guidelines of recommended safe weights for tasks involved in one-hand lowering activity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.72-81
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• 2014

Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site, forestry, farming, and daily life. The objective of this study was to compare one-hand lowering activity to lifting activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level with two workload 7.5kg and 15.0kg. Eight male subjects with LMM were asked to perform lifting/lowering tasks using both a one-handed (left-hand and right-hand) as well as a two-handed technique. Spinal loading was estimated through an EMG-assisted free-dynamic biomechanical model. The biomechanical stress of one-hand lowering activity was shown to be 43% lower than that of one-hand lifting activity. It was claimed that the biomechanical stress for one-hand lifting/lowering activity is almost twice (194%) of the one for two-hands lifting/lowering activity. It was also found that biomechanical stress by one-hand lowering/lifting activity with the half workload of two-hands lowering/lifting activity was greater than that of the two-hands lowering/lifting activity. Therefore, it might be a risk to consider the RWL of one-hand lowering/lifting activity to simply be a half of the RWL of two-hands lowering/lifting activity recommended by NIOSH.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.4
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• pp.24-30
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• 2002

In grinding operations, one of the most important problems is to increase efficiency of process. In order to achieve this purpose, it is necessary to administer the tool lift of grinding wheel and to optimize grinding conditions. Frequently dressing result in lowering the process efficiency remarkably and makes production cost high. On the other hand, grinding with a worn wheel causes the workpiece surface roughness to increase and often results in the occurrence of such troubles as chatter vibration and homing.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.11-18
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• 1998

In grinding operations, one of the most important problems is to increase efficiency of process. In order to achive this purpose, it is necessary to administer the tool life of grinding wheel and to optimize grinding conditions. Frequently dressing result in lowering the process efficiency remarkably and makes production cost high. On the other hand, grinding with a worn wheel causes the workpiece surface roughness to increase and often results in the occurrence of such troubles as chatter vibration and burning.

• Journal of the Korea Safety Management & Science
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• v.24 no.2
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• pp.113-126
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• 2022

This study examined the effect of railway traffic controllers' negative perception of organizational culture on their job demand and job satisfaction in relation to the moderating effect of self-efficacy. Results showed that the aggressive/defensive culture based on power and competition, had a positive (+) effect on job demand and job satisfaction. On the other hand, in the conditional process model in which self-efficacy affects the relationship between organizational culture, job demand, and job satisfaction, self-efficacy played a significant role in lowering the level of job demand, and it contributed to the increase of job satisfaction through a mediating effect. This results suggest the needs for lowering the level of job demand by changing the present aggressive/defensive organizational culture into the constructive one. And also, much consideration for maintaining the level of their self-efficacy should be spent.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.88-97
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• 2012

The muscle strengths in various postures are still used in the workplace, although mechanization and automation have been continuously accomplished. The aim of this study is to measure the maximum muscle strength and analyze the muscle fatigue during the various wrench jobs which are one of the upper limbs related works. Four hundreds and eighty five college students (243 males and 242 females) participated in this study. Twelve muscle strengths which are using for pulling, pushing, lifting and lowering the wrench with various postures are measured. For every moment, the muscle strengths for both hands were measured. In each measurement, five seconds averaged value and peak value were collected. The averaged value of preferred hand and non-preferred hand was compared. Also, the averaged value of opposite movement was compared through t-test. The fatigue of agonist for each movement was analyzed using EMG analysis. The result of this study can provide some basic information not only in designing the tools in work but also in selection, training and management of workers.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1785-1793
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• 2008

Fifty-four PIC barrows were used to evaluate the effects of lower dietary lysine content and energy level on carcass characteristics and meat quality in slaughter pigs. Pigs were allotted to one of three treatments by body weight with six replicate pens in each treatment. The dietary treatments for body weights of 20-50 kg, 50-80 kg and 80-90 kg were as follows, respectively: control diet (digestible energy 14.22 MJ/kg, lysine/DE 0.67 g/MJ, 0.53 g/MJ and 0.42 g/MJ); a low lysine group (digestible energy 14.22 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ); and a low lysine-low energy group or low nutrient group (digestible energy 13.11 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ). The daily weight gain, daily feed intake and feed efficiency were calculated in the overall growth period (nearly 12 weeks). Meanwhile, carcass characteristics and meat quality were evaluated at 60 and 90 kg body weight respectively. During the overall growth trial, lowering dietary lysine and nutrient level both decreased weight gain (p<0.05) and feed efficiency (p<0.01). At 60 kg body weight, decreasing dietary lysine and nutrient level noticeably decreased dressing percentage (p<0.01) and back fat depth at last rib of PIC pigs (p<0.01), but enhanced marbling scores (p<0.10), intramuscular fat content (p<0.10) and water loss rate (p<0.01) of the longissimus dorsi muscle. At 90 kg body weight, lean percentage (p<0.01) was evidently reduced by both lowering lysine content and nutrient level in the diet. However, the shoulder back fat depth (p<0.05) and marbling scores of the loin eye muscle (p<0.05) were increased; Lowering dietary nutrient level could improve back fat depth of 10th rib (p<0.01) and last rib (p<0.01), intramuscular fat content (p<0.10), redness (p<0.01) and water loss rate of the loin eye muscle (p<0.05), but decrease loin area (p<0.05). Finally, when comparing the 60 kg and 90 kg slaughter weights, it was found that the shoulder back fat depth (p<0.01, p<0.10), 6th-7th rib (p<0.01, p<0.01), 10th-rib (p<0.01, p<0.01) and last rib back fat depth (p<0.01, p<0.01) of the low lysine and low nutrient group were all obviously increased comparing with the control group. Taken together, the results showed that decreasing dietary lysine content and nutrient level increased intramuscular fat content and water loss rate of longissimus dorsi muscle; On the other hand, both lowering dietary lysine and nutrient level markedly compensated to increase back fat deposition in the later finishing period (body weight from 60 to 90 kg) in contrast to the control group.

• Journal of Korea Water Resources Association
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• v.46 no.7
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• pp.783-794
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• 2013

Saline groundwater, in addition to fresh groundwater, is actively developed for inland aqua culture in Jeju Island where groundwater is practically the only source of freshwater. In this work we analyzed impacts of saline and fresh groundwater development on groundwater systems in Sungsan subwatershed in Jeju. A sharp-interface model was used to simulate fresh and saline groundwater flows. Withdrawal of freshwater imparted adverse impacts by lowering groundwater level and inducing saltwater encroachment. Withdrawal of saline water imparted mixed results: on one hand it lowered groundwater level, on the other hand it reduced saltwater encroachments. However, freshwater development lowered groundwater level much more than salinewater development did. Modified Ghyben-Herzberg ratio was developed for a transition zone with finite width. Comparison against observed data resulted in fair agreement.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.3
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• pp.350-355
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• 2009

This study was performed to evaluate the sodium and potassium content of the 19 kinds of side dish purchased from traditional market and super market in Daejeon area. The results are summarized as follows. Sodium content(mg/100 g) among samples was the highest in the Jangachies. The sodium contents of Yeongeun jorim, Bellflower saengchae, Kkaetip jangachies, Chonggak kimchi, Changranjut in super market were significantly higher than those of the traditional market (p<0.05). On the other hand, the sodium contents of the other side dishes in traditional market were significantly higher those in super market. These results suggested that the sodium content of side dishes in the traditional market were higher than those in the super market. Sodium intake from Kimchi and Jangachies per one serving size is estimated significantly highest among samples. Also, potassium content of side dishes were low detected compare to sodium content and potassium content of side dishes in the traditional market were higher than those in the super market. From these results, it was suggested that food labeling (Na content) on the package of side dishes is to be required for lowering Na intake, and standard cooking methods is to be established.

• Journal of Korean Medicine for Obesity Research
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• v.5 no.1
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• pp.121-131
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• 2005

During last few decades dietary guidelines for the weight management mainly have focused on a low-fat, high carbohydrate diet. Carbohydrate was supposed to be low-dense, highly satiating as well as it affects little on the lipogenesis. Although low-fat diet has significant weight-reducing effect, the loss was modest and usually regained after cessation of the diet. Furthermore, low-fat, modest-carbohydrate diet did not impact on the ever increasing rates of overweight and obesity. Alternative approaches include low-carbohydrate diet, high-carbohydrate diet and low-glycemic index diet. Although none of above mentioned diet have sufficient evidence for standard weight management diet, short-term efficacy and safety are being approved continuously. Low-carbohydrate diet contains less than 45% of carbohydrate in daily energy consumption, it is claimed to have more satiating effect and to improve metabolism. However, low compliance due to the limitation of food choice should be considered on prescribing the diet. High-carbohydrate which contains 90% of carbohydrate in total daily energy consumption, is effective in providing satiety and lowering total calorie intake and cholesterol. On the other hand, nutritional unbalance should be took into account. Low-glycemic index diet is based on the theory that contemporary diet contains significantly less fiber and unrefined carbohydrate, therefore insulin secretion is disturbed. Because low glycemic index food slowly increase blood glucose and insulin level, it induces much satiating effect and may decrease calorie ultimate intake. However, poor standardization of glycemic index is one of the main obstacle for the diet to be applied in the clinic. Meanwhile, high fructose food and beverage should be discouraged because it has little satiating effect and may cause insulin resistance. High fiber food is another recommendation for healthy, lean diet.