The purpose of this study is to develop an efficient algorithm for the management of the shift schedule in nuclear power plants in consideration with the ergonomic criteria and the regulatory codes. The ergonomic criteria considered are the work hours, overtime-work frequency and working time, start and finishing time of works, allocation of rest times and duty-offs, rotating of shifts, etc. to comply with the regulations such as the Labor Standard Act, the ILO Convention No. 171, 178, "the detailed content of a periodic safety review," enforcement regulations 19-2 of the Atomic Energy Act. The developed algorithm for the shift schedule program adopts a heuristic method to minimize the difference the workload for shift workers in nuclear power plants.

1/f fluctuation characteristics can be seen in various natural phenomena, such as breezes, streams, candle flames and the luminous patterns of fireflies. It is said that the 1/f fluctuation are comfortable for human beings. And they are introduced into many industrial products, such as an air conditioner, music, lighting, etc. This study focused on verifying the effects of 1/f fluctuation sound on comfort sensibility. Stimulus were divided into three groups(Group 1, 2, 3) by sound generation methodology. Fluctuation patterns of group 1, 2 were given by three types of fluctuation, 1/f0, 1/f1, 1/f2, and its of group 3 were given by two types of pure tone, 1/f1. In order to verify the effects, we measured the physiological responses of the subjects such as EEG(Electroencephalogram), ERP(Event-Related Potential), and these physiological responses were compared with subjective assessments, free answers. Consequently, we found that factor which had an effect on comfort sensibility was cognitive factor(for stimulus) rather than 1/f fluctuation sound pattern.

The purpose of this study is to determine the economical standard of road signs by verifying the difference of driver's recognition and reaction time according to the space rate of letters on the road signs. For this reason, indoor simulations was conducted to confirm difference of recognition and reaction time on six sign-targets having different space rate. Also, a negative binomial regression model was used to find the main factors which could lower the rate of misreading. For this model, increasing of legibility of sign is not only simple enlargement of sign, but also suitable match of letters and sign. The result of this study is capable of verifying the importance of the space rate in road signs, and being utilized as a effective method to determine the standard of the road signs.

The purpose of this study was to investigate the relationships between weights of backpack and back and shoulder pains of elementary school students in Korea. A cross-sectional sample of 278 boys and 233 girls aged between 7 and 12 years were analyzed for this study. 49.1% of the participated children reported their backpacks were felt heavy, and the weights of their backpack were grater than 13.3% of their body weight. About 65.4% of students carried greater than 10% of their body weights. The weight of the backpack showed significant positive relationship with shoulder pain but not with their back pain. The results of this study suggested that overweighed backpack could cause the musculoskeletal pain to the elementary school students. Therefore, an effective backpack safety program for parents and students is necessary to educate them how to prevent possible musculosketal pain related to the weight of backpack within the perspective of the ergonomical approach.

In a decision making process, the ambiguity of qualitative probabilistic expressions may result in a wrong conclusion. For this reason there had been many studies of quantifying qualitative probabilistic expressions in English-speaking countries. In this research, quantification of Korean qualitative probabilistic expressions is conducted through 4-step questionnaires. The numerical data of 78 verbal phrases were collected in the first questionnaire and classified in two categories (i.e., uncertainty and frequency). In each category, qualitative probabilistic expressions were divided into eleven groups according to the similarity of the numerical values. In the second questionnaire, subjects selected a representative expression for each group, which totaled 11. In the third questionnaire each subject was asked to rank eleven expressions from 1 to 11 with 1 indicating the highest probability. At last, subjects conducted pairwise comparisons to obtain relative weights, which are used to convert into the numerical probability scale.

The concept of universal design has recently emerged as an important aspect of product design. Universal design is considerably analogous to ergonomic design in a way that it takes the capabilities and limitations of users into consideration during the product development process. However, relatively few studies have been devoted to reflect the practical use of ergonomic principles on universal design. This research attempts to develop a universal design index for mobile phone design to quantify how well a product complies with principles of universal design. The research also emphasizes on ergonomic principles as a basis of evaluation. A generation of the evaluation items was done by cross-checking among the personal, activity and product components. Personal components consist of human characteristics including age, physique, perceptual capacity, life-style, etc. Activity components were derived from those scenarios of mobile phone use while product components were composed of the parts to which a user interacts. Further analysis systematically generated a universal index from relationship matrices among the three components. The index was then used to test its suitability by applying to the evaluation of mobile phones currently on the market. This study demonstrates a development process through which evaluations can be made possible for universal design. The research suggests an improved approach to the appraisal of how well mobile phones are universally designed based on ergonomic principles.

Consumer satisfaction and feelings with form play an essential role in determining the success of a product. However, contemporary industrial design processes typically employ designer driven, intuitive methods for generating and evaluating form concepts. This paper describes the implementation process of web based design support system that helps assess customer's feelings or sensibilities of forms created in each stages of design process. The present web based approach provides designers with fast and various feedbacks about their design in each stage by using assessment with object VR and web 3D as well as ordinary 2D images. Practical application for exterior design of electric vehicle was illustrated and the further refinement of the design support system was discussed.

A construction robot has been developed for higher productivity and better safety in various construction fields. Especially, curtain wall is suitable for outer wall material of tall commercial building and apartment complexes. This heavy material is, however, hard to install with a manpower and outdated equipment. For this reason, the prototype of ASCI (Automation System for Curtain wall Installation) was developed. This system has a robot controller(i.e. hand-held remote control unit) for the transfer information signal between human operator and robot system. Although study has been conducted on manual controller of ASCI, hardly any information is known about the operator's opinion. In this study, a questionnaire was completed by operator to get their opinion about aspects which need to design a more comfortable and productive manual controller of construction machinery, robot included. Through the result of study, it is expected that this technical data is contributed to the robot controller design for comfort and productivity of various industrial machinery.

Despite the government promoting women's participation in the engineering field, some statistics show that it has yet to be achieved. Potential reasons for this phenomenon include lower level of applications by women, or inherent gender gap in the professional field. Therefore, this study attempted to find impact of gender on college admission from the Lens Model perspective and Signal Detection Theory. This study consisted of three phases: identifying the necessary cues used in the admission process, analyzing existing data, and conducting two experiments to identify the effect of gender on admission decisions. Although the college application consisted of many cues, only five cues, school ranking, GPA, SAT score, resident status, and gender, were used to capture the officers' judgment policies for engineering admissions. Two experiments were conducted to investigate the impact of the gender factor in college admission. The enrollment officers first were presented with the existing data without the gender and asked to make dichotomous judgments. Secondly, the officers were asked to perform the judgment task with the gender cue present. Results showed that the gender did not play an important role in the judgments as expected. However, ideographical analyses on judgment strategies revealed that there were significant differences between the admission officers. Possible training implications are discussed.

This study examined whether there is a transfer effect to other joint angles and the angular specificity of muscle fatigue after 6 weeks of isometric training of the vastus medialis. Twenty subjects were randomly assigned to 30° and 90° knee flexion groups and were trained at 80% maximal voluntary isometric contraction(MVIC) three times a week for 6 weeks. The pre-and post-training values of the 80% holding time(endurance time) of MVIC, the Fatigue Index(FI), and the MVIC at 30°, 60°, and 90° were compared. After isometric training for 6 weeks, in the 30° knee flexion group, FI decreased significantly(p<0.05) only at 30°, which was the training angle; there was no change at other angles. By contrast, in the 90° knee flexion group, FI decreased significantly(p<0.05) at both the trained angle and at the other angles, indicating a transfer effect of training. MVIC did not increase significantly(p<0.05) at any trained angle in either the 30° or 90° knee flexion groups after 6 weeks of isometric training, neither did the 80% holding time of MVIC differ significantly compared with pre-training in either group. These findings suggest that training at 90° of knee flexion is more effective than training at 30° of knee flexion for obtaining a training transfer effect on muscle fatigue in the vastus medialis.

The purpose of this study was to evaluate an effect of the new air traffic control display designed by Ecological Interface Design [EID]. The methodology of EID has not been applied to the development of the air traffic control display so far. To design a new air traffic control display by EID, We implemented Work Domain Analysis about the air traffic control domain and made the Work Domain Model that consisted of the five levels of the Abstraction Hierarchy. We extracted the Information Requirement from the completed Work Domain Model and the extracted information requirements from the model were used to design the new air traffic control display. We evaluated an effect of the new air traffic control display designed by EID. Participants for evaluating consisted of 14 active military air traffic controller of the Republic of Korea Air Force. Experiment was designed two factors within subject. Factors manipulated in the experiment included displays type to compare the existing type with the new ecological interface type and included complexity to compare the effect of the high complex situation with the effect of the low complex situation. Response time about questions with relation to air traffic collision situation, accuracy, and subjective work load were measured. The results reveled that EID type's display has a significant effect on response time, accuracy, and subjective work load and verified that EID could be applied to the air traffic control domain that is more complex and dynamic.

To investigate the effects of independent suspension technology(IST) of hiking boot on the stability and load of foot, eight participants performed medial and lateral drop landing from 33.4cm height and 85cm distance to uneven surface while wearing normal & IST hiking boots. For the stability of foot during the drop landing, the balance angle & suspension angle and rearfoot angle was analyzed using high-speed video analysis. Also kinetic analysis using the force plate and insole pressure measurement was conducted to analyze vertical & breaking ground reaction force and pressure distribution. Not only the balance angle & suspension angle but also rearfoot angle was improved with IST boots for lateral drop landing. These results indicate the IST boots may have the suspension function which keeps the foot to be stable during landing. However the IST boots did not show any effect for medial landing. This might be related to the hardness of medial part of outsole. Therefore the softer outsole of medial part could be recommended. Furthermore the impact force & breaking force and insole pressure were reduced with IST boot. These results means that IST boot has not only cushioning effect but also good grip effect. Therefore the hiking boots applied the independent suspension function may help to reduce fatigue and prevent injury such as ankle sprain in hiking on uneven surface.

Although population of the elderly is increasing rapidly, the older adults are the least users of the Internet in Korea. Prior research suggests that older adults are physically and psychologically disadvantaged when using the Internet. With the existence of the digital divide over different age groups, the objectives of this study were to identify the current status of Internet usage of Korean adults and to suggest some alternatives for solving digital divide on Internet usage. A total of 654 Korean adults, including the elderly, participated in both on-line and off-line (on-site interview) surveys using structured questionnaires. The results of statistical analyses indicated that the gap between the percentages of Internet users in younger and older groups was significantly wide, though many older adults had strong interests of Internet. To reduce this gap on digital divide, with an appropriate help from family and government, several characteristics of the elderly should be considered in designing some age-related web sites. Some effective alternatives suggested in this study may be used as basic data for universal design of Internet-oriented software.

he purpose of this study is to measure bio-signal to investigate the driver's physiological response change under real situation using train simulator. The train simulator used in this study is KTX model and according to changes of driving situation, The bio-signal controlled by autonomic nervous system, such as GSR(Galvanic Skin Response), SpO2(Saturation percent O2), HR(Heart Rate), ECG(Electrocardiograph), EEG(Electroencephagram) and movement and response of eye were measured. Statistically significant difference in bio-signal data and eye movement activity pattern were investigated under several different driving speeds using analysis of variance (p<0.05). The GSR and HR value measured in average and mission speed operation is higher than in high-speed operation. β wave of EEG in average speed operation become more activated than in high speed operation. In accordance with a characteristic of rail vehicle, movement and response of eye in high-speed operation requiring relatively simple maneuver become less activated than in either average or mission speed operations. Conclusively, due to more careful driving controls in average and mission speed operation are required than in high-speed operation, level of mental and physical stresses of train driver was increased and observed through changes of bio-signal and eye movement measured in this study.

The goal of this study is to find out correlation between Driver's Unsafe acts(errors and violations) and Personality types. The experiment was performed on 180 subjects, men and women between 20's and 60's having experience in driving for 6 months at least. Personality types of the subjects were classified by MBTI(Myers-Briggs Type Indicator) GS type and Driver's unsafe acts were measured by KDBQ(Korean Driver Behavior Questionnaire) based on Reason's DBQ(Driver Behavior Questionnaire). The result of experiment showed several facts about the relation. The first is that the drivers of P (Perceiving) type commit more violations and slips than drivers of J(Judging) type. The second is that in the comparison among attitude indexes(EP, EJ, IP, IJ) the drivers of EP(Extroversions - Perceiving) commit more violations than other type drivers. Finally, only men of P(Perceiving) type commits more violations than men of J(Judging). Based on these facts, it is possible to use Personality types as a device to prevent unsafe acts in various fields for driver selection and accident prevention training classified by Personality types etc.

The objective of this study is to investigate the perceived discomfort for postures combined with shoulder flexion/extension and elbow flexion, and external load. 12 healthy male undergraduate and graduate students participated in this experiment. Experimental variables were the shoulder flexion/extension angle(-20°, 0°, 45°, 90°, 135°), the elbow flexion angle (0°, 45°, 120°), and the external load(0, 1.5Kg, 3Kg) as independent variables and a whole body perceived discomfort using Borg's CR10 as a dependent variable. The subjects maintained the given posture for 60 seconds and then rated the perceived discomfort. The ANOVA results showed that all main factors and two-way interactions were statistically significant at α=0.05. As a result of regression analysis to examine the effect of external load on the perceived discomfort, the perceived discomfort linearly increased as the level of external load increased. Then, the effect of external load on the perceived discomfort was quantitatively classified into three levels based on the result of regression analysis.

The objective of this study was to establish a systematic ergonomic program for the prevention and control of work-related musculoskeletal disorders(WMSDs) in a machinery manufacturing company. The steps such as looking for the signs of WMSDs problems, setting the stage for action, training-building in-house expertise, gathering and examining the evidence of WMSDS, developing controls of health care management, and proactive ergonomic interventions were applied. The primary success factors were management commitment and encouragement, and harmonious union-management relations.