• Tunnel and Underground Space
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• v.31 no.6
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• pp.593-609
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• 2021

We proposed a numerical method for the thermo-mechanical behavior of rock fracture using a grain-based distinct element model (GBDEM) and simulated thermally induced fracture slip. The present study is the benchmark simulation performed as part of DECOVALEX-2023 Task G, which aims to develop a numerical method to estimate the coupled thermo-hydro-mechanical processes within the crystalline rock fracture network. We represented the rock sample as an assembly of Voronoi grains and calculated the interaction of the grains (blocks) and their interfaces (contacts) using a distinct element code, 3DEC. Based on an equivalent continuum approach, the micro-parameters of grains and contacts were determined to reproduce rock as an elastic material. Then, the behavior of the fracture embedded in the rock was characterized by the contacts with Coulomb shear strength and tensile strength. In the benchmark simulation, we quantitatively examined the effects of the boundary stress and thermal stress due to heat conduction on fracture behavior, focusing on the mechanism of thermally induced fracture slip. The simulation results showed that the developed numerical model reasonably reproduced the thermal expansion and thermal stress increment, the fracture stress and displacement and the effect of boundary condition. We expect the numerical model to be enhanced by continuing collaboration and interaction with other research teams of DECOVALEX-2023 Task G and validated in further study experiments.

• The Journal of Society for e-Business Studies
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• v.26 no.3
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• pp.133-153
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• 2021

Recently, organizations are making significant technology investments to build a centralized content management system. However, high-quality technology adoption can conversely create techno-stress in the user and cause negative behavior. The purpose of this study is to suggest the negative effects and mitigation directions of enterprise content management system(ECMS) related techno-stress. In order to verify the hypothesis, this study conducted a questionnaire survey on employees of organizations that adopted content management technology and conducted structural equation modeling. As a result of the analysis, ECMS related techno overload and complexity decreased the intention of continuous use of ECMS. But, internal communication activities reduced ECMS related techno stress and task-technology fit moderated the relationship between techno-stress and intention of continuous use of ECMS. The study has implications in terms of suggesting a strategic direction to minimize the negative causes of the use of content management systems.

• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.1-8
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• 2005

A new design of shoulder straps and frame of backpack is proposed for reducing compression and fatigue of shoulder. The stress reduction effects of a backpack equipped with the newly designed shoulder straps and frame have been analyzed statistically through various experiments. We show that the newly designed shoulder straps(wider than the conventional ones) is superior to existing shoulder straps in respect of RPE, task performance measure and physiological measure. The new frame is also proven to be superior to existing frame in respect of RPE and task performance measure. In conclusion, the proposed shoulder straps and frame are shown to enhance the task performance of soldiers.

• Human Ecology Research
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• v.53 no.4
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• pp.463-473
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• 2015

The fashion industry has distinctive characteristics. It is important to understand the specific working environment and unique problems at fashion corporations in order enhance employee efficiency. However, studies on job stress for fashion employees remain limited. This study used qualitative research to examine major job stress factors for fashion company workers. In-depth interviews were conducted on 6 respondents who work in various departments at fashion manufacturing companies. We identified task-related factors and structural factors as the two major job stress factors. Task-related factors consisted of 4 elements (necessity of massive knowledge, overtime outside work, tight schedules, and organizational tasks); structural factors consisted of 3 elements (burden of sales outcome, formal relationships, and anxiety of salary retirement). The results indicated that respondents consistently tried to gain knowledge about the latest trends and field experiences that caused mental and physical exhaustion due to the necessity of working late. Designers and workers in the sales department were constantly evaluated by their sales results compared to other workers that caused high levels of stress. Respondents answered that building relationships was an important factor in the fashion industry and sometimes felt that building formal relationships was more important than the ability to do work.

• The Journal of Information Technology
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• v.3 no.1
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• pp.177-189
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• 2000

It was investigated this study how much individual's job stress would be explained by formalized task environment. also, would be explained locus of control as moderate variable. The data used in the study were collected from employees in domestic corporate. After sending the total of 150 questionnaires, 113 responses were returned. Among the returned questionnaires, 9 poor responses were excluded, and the remained 104 copies were analyzed. The final regression model included formalized task environment as statistically significant, but locus of control as statistically non-significant. it was relied on a lack of sample. This study was to open job stress studies up multi level study(individual - organizational level).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.57-68
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• 1998

Work environments have been changed with the advent of new technologies, such as computer technology. However, human cognitive limits can't pace up with the change of work environment. Designing human-computer system requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under limited reaction time and/or urgent situation, human operator may the work stress, work error and resultant deleterious work environment. This paper evaluate the visual factors of major information processing factors(information density, amount of information, operational speed of speed)on operator performance of supervisory control under urgent(limited reaction time)environments which require deleterious work condition. To describe the work performance int the urgent work situations with time stress and dynamic event occurrence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount, system proceeding speed, information density) were evaluated using five dependent variables. The result of statistical analyses indicate that the amount of information affected on all of five dependent measure. Number of failure and number of secondary task score were influenced by both amount of information and operational speed of system. However reaction time of secondary task were affected by both amount of information and information density. As a result, the deleterious factors for the performances seemed to be a scanning time to supervise each control panel. Consequently, a new display panel was suggest to reduce operator work load for scanning task showing better operator performance.

• Tunnel and Underground Space
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• v.31 no.4
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• pp.270-288
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• 2021

We proposed a numerical method to simulate the hydro-mechanical behavior of rock fracture using a grain-based distinct element model (GBDEM) in the paper. As a part of DECOVALEX-2023 Task G, we verified the method via benchmarks with analytical solutions. DECOVALEX-2023 Task G aims to develop a numerical method to estimate the coupled thermo-hydro-mechanical processes within the crystalline rock fracture network. We represented the rock sample as a group of tetrahedral grains and calculated the interaction of the grains and their interfaces using 3DEC. The micro-parameters of the grains and interfaces were determined by a new methodology based on an equivalent continuum approach. In benchmark modeling, a single fracture embedded in the rock was examined for the effects of fracture inclination and roughness, the boundary stress condition and the applied pressure. The simulation results showed that the developed numerical model reasonably reproduced the fracture slip induced by boundary stress condition, the fracture opening induced by fluid injection, the stress distribution variation with fracture inclination, and the fracture roughness effect. In addition, the fracture displacements associated with the opening and slip showed good agreement with the analytical solutions. We expect the numerical model to be enhanced by continuing collaboration and interaction with other research teams of DECOVALEX-2023 Task G and validated in further study experiments.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1172-1175
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• 2007

We have investigated the threshold voltage shifts(${\Delta}Vth$) and drain current level shift (${\Delta}Ids$) in subthreshold region of a-Si:H TFTs induced by DC Bias (Vgs and Vds) - Temperature stress (BTS) condition. We plotted the transfer curves and the ${\Delta}Vth$ contour maps as Vds-Vds stress bias and Temperature to examine the severe damage cases on TFTs. Also, by drawing out the time-dependent transfer curve (Ids-Vgs) in the region of $10^{-8}\;{\sim}\;10^{-13}$ (A) current level, we can estimate the failure time of TFTs in a operating condition.

• Journal of the Ergonomics Society of Korea
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• v.9 no.1
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• pp.15-20
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• 1990

In order to design man-machine system, communication system and other tasks that require information, we need to understand the characteristics of hyman short-term memory (STM). Thus, the purpose of this thesis is to investigate the influences of information stress and retention time on human performances and their relation- ships for STM of visual invormation. Eight subjects performed the computer monitering with STM task. The results showed that performance on serial recall from STM get wores and response time (and completion time) on information transmission by recall from STM increase as information stress and retention time increase. Also, there existed inverse proportional relationship between recall performance and response time (and completion time).

• Journal of Information Technology Applications and Management
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• v.18 no.4
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• pp.119-130
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• 2011

When an organization adopts new technology, performance through the technology is expected to be decided depending on attitudes of the members, in that technology produces performance only if the members zealously use it. Therefore, the members need to devote themselves to acquire and use the new technology. This attitude of members is called "IT acceptance will" (Ranarajan et al., 2005), and this research is to examine the effect of an individual's "IT acceptance will" on performance. Thus, this research analyzes what increases IT acceptance will and what effect IT acceptance will has on stress due to uncertainty of an organization-job complexity and role conflict- through new IT adoption. This research conducted a survey from July to September in 2009, targeting employees of government offices and public institutions in Kyunggi and Kyungnam provinces. Then, a total of 370 was collected and the final 344 was selected for our research analysis. As a result, this research found out that personal innovation and client orientation improved an individual's IT acceptance will, which improved performance through new IT adoption. However, the new IT adoption also increased job complexity and role conflict, but negative effects of stress on performance was not found as IT adoption will diminished the stress. Based on this result, this research discussed practical and academic implications and the limitations.