• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.5
• /
• pp.155-162
• /
• 2019

Recent changes in corporate environment, both internal and external, have led to permanent restructuring, which has left baby boomers facing a serious threat to their jobs due to an unprepared involuntary retirement. In line with this period of time, resilience has become important in terms of overcoming the psychological hardships of retirement. In response, the study conducted a study on the effect of resilience on career path conversion among involuntary retirees of baby boomers. The effect on career conversion on the personal characteristics of baby-boomer retirees has been verified by significant differences in gender and job type. In addition, the results of verification of the effect of recovery elasticity on career path transition confirmed that recovery elasticity has a very significant effect on career path transition, and the positive effect of the positive factors among the lower factors was verified to have a very significant positive effect on situational perception, coping method and support, and it was confirmed that interpersonal ability also has an effect on positive effect. However, the ability to self-control did not have a significant effect. Thus, for baby boomers who have to prepare for career transformation after retirement, the resilience has been proven to be a very necessary ability to overcome their hardships and make successful adaptations, and it is expected that it will be very useful in the course of career transition counseling for baby boomers.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.32 no.2
• /
• pp.55-60
• /
• 2022

In this study, a heat treatment experiment was conducted to select a new melt composition that can easily control the unintentionally doped nitrogen (N-UID) without degrading the SiC single crystal quality during TSSG process. The experiment was carried out for about 2 hours at a temperature of 1900℃ under Ar atmosphere. The used melt composition is based on either Si-Ti 10 at% or Si-Cr 30 at%, and also Co or Sc transition metals, which are effective for carbon solubility, were added at 3 at%, respectively. After the experiment, the crucible was cross-sectionally cut, and evaluated the Si-C reaction layer on the crucible-melt interface. As a result, with Sc addition, Si-C reaction layers uniformly occurred with a Si-infiltrated layer (~550 ㎛) and a SiC interlayer (~23 ㎛). This result represented that the addition of Sc is an effective transition metal with high carbon solubility and can feed carbon sources into the melt homogeneously. In addition, Sc is well known to have low reactivity energy with nitrogen compared to other transition metals. Therefore, we expect that both growth rate and Nitrogen UID can be controlled by Si-Sc based melt in the TSSG process.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.5
• /
• pp.72-81
• /
• 2018

In this study, the sinusoidal-wave driving method, six-step driving method, and twelve-step driving method, which can be used in an inverter for permanent-magnet synchronous motors, were simulated, and the results were compared to review their operating performance. These driving methods were classified according to the electrical conduction angle and phase current of the motor. Conventionally, only the transition control technique between the sinusoidal-wave driving method and six-step driving method was studied for the efficiency of the inverter. In this paper, however, comparative analysis was focused on a variety of transition control applications to use the advantages of each driving method. For this purpose, computer simulations for these driving methods were carried out to obtain the motor torque, speed control characteristics, and THD of the motor phase currents. As a result, the sinusoidal-wave driving method showed the best performance in all respects. The six-step driving method has better speed control characteristics than the twelve-step driving method, and the twelve-step driving method has a lower THD of the motor phase currents than the six-step driving method.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.308-313
• /
• 2005

For a real-time quadruped robot running control, there are many important objectives to consider. In this paper, the running control architecture based on global states, which describe the cyclic target motion, and central pattern is proposed. The main goal of the controller is how the robot can have robustness to an unpredictable environment with reducing calculation burden to generate control inputs. Additional goal is construction of a single framework controller to avoid discontinuities during transition between multi-framework controllers and of a training-free controller. The global state dependent neuron network induces adaptation ability to an environment and makes the training-free controller. The central pattern based approach makes the controller have a single framework, and calculation burden is resolved by extracting dynamic equations from the control loop. In our approach, the model of the quadruped robot is designed using anatomical information of a cat, and simulated in 3D dynamic environment. The simulation results show the proposed single framework controller is robustly performed in an unpredictable sloped terrain without training.

• Tuberculosis and Respiratory Diseases
• /
• v.74 no.3
• /
• pp.104-110
• /
• 2013

Background: Notified tuberculosis (TB) cases in Korea have not decreased over the last decade (2001-2010). Methods: To clarify the reasons, we analyzed an annual report on notified tuberculosis patients and age-specific population drift in Korea. Results: Compared to the age-specific notified TB cases between 2001 and 2010, distinctive features in notified TB cases and new cases increased markedly in people aged 45-54 years and in patients over 65 years old, whereas those between 15-34 years in 2010 decreased drastically. In particular, notified TB individuals over 65 years old occupied 29.6% of the cases in 2010, which was 1.5 times higher than that in 2001. The main reason not to decrease in notified TB patients for the last decade (2001-2010) was due to the increasing elderly population as well as the aging of baby boomers, which have a higher risk of TB development. Conclusion: Korea needs to pay attention to the older population in order to successfully decrease the burden of TB in the future.

• Journal of computational fluids engineering
• /
• v.15 no.4
• /
• pp.46-52
• /
• 2010

In the present work, the aerodynamic characteristics of elliptic airfoils which have a 12% thickness ratio are numerically investigated based on Reynolds-averaged Navier-Stokes equations and a transition SST model at a Reynolds number 8.0$\times$105. The numerical simulation of a synthetic jet actuator which is a well-known zero-net-mass active flow control actuator located at x/c = 0.00025, was performed to control massive flow separation around the leading edge of the elliptic airfoils. Four cases of non-dimensional frequencies were simulated at an angle of attack of 12 degree. It is found that the size of the vortex induced by synthetic jets was getting smaller as the jet frequency becomes higher. Comparison of the location of synthetic jets between x/c = 0.00025 (around the leading edge) and x/c = 0.9 (near the separation) shows that the control near the leading edge induces closed recirculation flow regions caused by the interaction of the synthetic jet with the external flow, but the control applied at 0.9c (near the trailing edge) induces a very small and weak vortex which quickly decays due to weak intensity.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.12
• /
• pp.1799-1808
• /
• 2006

This study was designed to explore the effects of marbling on meat quality characteristics and intramuscular connective tissue of beef longissimus muscle. Chemical determinations, histological and mechanical measurements were performed on the raw and cooked meat at d 4 postmortem. The results showed that crude fat, collagen, fiber diameter and maximum transition temperature of intramuscular connective tissue increased (p<0.05) with the increase of marbling score. The cooking losses, collagen solubility, WBSF and perimysial thickness decreased (p<0.05) with the increasing marbling. WBSF correlated (p<0.05) with moisture, crude fat, collagen, cooking losses, sarcomere length and perimysial thickness. The development of marbling results in the decline in cooking losses, the avoidance of sarcomere shortening, and the disorganization of the perimysia, which accounts for the improvement of beef tenderness.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.1127-1134
• /
• 2017

Gas turbine engine control was originated from a single hydro-mechanical governor for fuel metering and changed to 1970s' DEEC and then today's centralized FADEC. In order to attain the goal of improvement of control performance, application of PHM technology, and reduction of system weight, it is necessary to make a transition to distributed engine control. This paper describes the concept and roadmap of distributed control, collaborative efforts of government and industry for successful development of the system, and technical challenges for the system.

• The Plant Pathology Journal
• /
• v.40 no.3
• /
• pp.290-298
• /
• 2024

K-Maryblyt has been developed for the effective control of secondary fire blight infections on blossoms and the elimination of primary inoculum sources from cankers and newly emerged shoots early in the season for both apple and pear trees. This model facilitates the precise determination of the blossom infection timing and identification of primary inoculum sources, akin to Maryblyt, predicting flower infections and the appearance of symptoms on various plant parts, including cankers, blossoms, and shoots. Nevertheless, K-Maryblyt has undergone significant improvements: Integration of Phenology Models for both apple and pear trees, Adoption of observed or predicted hourly temperatures for Epiphytic Infection Potential (EIP) calculation, incorporation of adjusted equations resulting in reduced mean error with 10.08 degree-hours (DH) for apple and 9.28 DH for pear, introduction of a relative humidity variable for pear EIP calculation, and adaptation of modified degree-day calculation methods for expected symptoms. Since the transition to a model-based control policy in 2022, the system has disseminated 158,440 messages related to blossom control and symptom prediction to farmers and professional managers in its inaugural year. Furthermore, the system has been refined to include control messages that account for the mechanism of action of pesticides distributed to farmers in specific counties, considering flower opening conditions and weather suitability for spraying. Operating as a pivotal module within the Fire Blight Forecasting Information System (FBcastS), K-Maryblyt plays a crucial role in providing essential fire blight information to farmers, professional managers, and policymakers.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.324-329
• /
• 1993

A reduction method of GSPN (generalized stochastic Petri net) is proposed. A GSPN is basically a SPN (stochastic Petri net) with transition a that are either timed or immediate. Then the proposed method is defined on the basis of the dynamic behavior and the structure of the net. The reduction preserves the properties such as liveness, boundedness, and allows easy analysis of the GSPN.