• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.6
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• pp.1-14
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• 2007

Optimal design method of nonlinear damping system for seismic response control of adjacent structures is studied in this paper. The objective functions of the optimal design are defined by structural response and total amount of the dampers. In order to obtain a solution minimizing two mutually conflicting objective functions simultaneously, multi-objective optimization technique based on genetic algorithm is adopted. In addition, stochastic linearization method is embedded into the multi-objective framework to efficiently estimate the seismic responses of the adjacent structures interconnected by nonlinear hysteretic dampers without performing nonlinear time-history analyses. As a numerical example to demonstrate the effectiveness of the proposed technique, 20-story and 10-story buildings are considered and MR dampers of which hysteretic behaviors vary with the magnitude of the input voltage are considered as nonlinear hysteretic damper interconnecting two adjacent buildings. The proposed approach can provide the optimal number and capacities of the MR dampers, which turned out to be more economical than the uniform distribution system while maintaining similar control performance. The proposed damper system is verified to show more stable performance in terms of the pounding probability between two adjacent buildings. The applicability of the proposed method to the design problem for optimally placing semi-active control system is examined as well.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.4 s.50
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• pp.77-84
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• 2006

Recently, as large structures such as high-rise building and long span bridge become lighter and more flexible, the necessity of structural control for reducing excessive dynamic response due to seismic excitation is increased. In this study, a semi-active base isolation system using Magneto-Sensitive (MS) rubbers is proposed to effectively protect structures against earthquakes. MS Rubber is a class of smart controllable materials whose mechanical properties change instantly by the application of a magnetic field. To demonstrate the performance of this device, the MS Rubber isolation system is compared to Lead-Rubber Bearing (LRB) isolation systems and judged based on computed responses to several historical earthquakes. The MS Rubber isolation system is shown to achieve notable decreases in base drifts over comparable passive systems with no accompanying increase in base shears or in accelerations imparted to the superstructure. The proposed MS Rubber system is shown to perform better than the passive isolation system.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.51-54
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• 2005

Shape memory alloys (SMAs) find many applications in smart composite structural systems as the active components. Their ability to provide a high force and large displacement makes them an excellent candidate for an actuator for controlling the shape of smart structures. In this paper, using a macroscopic model that captures the thermo-mechanical behaviors and the two-way shape memory effect (TWSME) of SMAs smart morphing polymeric composite shell structures like shape-changeable UAV wings is demonstrated and analyzed numerically and experimentally when subjected to various kinds of pressure loads. The controllable shapes of the morphing shells to that thin SMA strip actuator are attached are investigated depending on various phase transformation temperatures. SMA strips start to transform from the martensitic into the austenitic state upon actuation through resistive heating, simultaneously recover the prestrain, and thus cause the shell structures to deform three dimensionally. The behaviors of composite shells attached with SMA strip actuators are analyzed using the finite element methods and 3-D constitutive equations of SMAs. Several morphing composite shell structures are fabricated and their experimental shape changes depending on temperatures are compared to the numerical results. That two results show good correlations indicates the finite element analysis and 3-D constitutive equations are accurate enough to utilize them for the design of smart composite shell structures for various applications.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1083-1089
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• 2010

Shape memory alloys (SMAs) are smart materials. The unique characteristics of SMAs enable the production of large force and displacement. Hence, SMAs can be used in many applications such as in actuators and active structural acoustic controllers; the SMAs can also be used for dynamic tuning and shape control. A SMA torque tube actuator consisting of SMA tubes and superelastic springs is proposed, and the behaviors of the actuator are investigated. From the results of heat transfer analysis, it is proved that the SMA torque tube actuator with both resistive heating of SMA itself and a separate conventional heating rod in the tube core has good performance. The behavior of an actuator system was analyzed by performing a contact analysis, and the twisting motion was noticed when checking the actuation. 3D SMA nonlinear constitutive equations were formulated numerically and implemented by performing a nonlinear analysis by using Abaqus UMAT.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.435-438
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• 2012

Today, In all fields, As combination of ubiquitous computing-based technologies between electronic space and physical space, has been active trend research about wireless integration sensor network between sensors and wireless technology. Also, but in ship is underway research about Ship Area Network(SAN) of intelligent ship to integrate wireless technology, ship is required SAN-bridge technology of a variety of wired, wireless network integration and heterogeneous sensor and interoperability of the controller and SAN configuration management technology of remote control. Ship keep safe of all the surrounding environment including crew besides structural safety and freight management monitoring. In this paper, for monitoring design such as on climate change detection and temperature, pressure about various structures, there identify technology trends for routing and data aggregation to use energy efficiency in wireless sensor network. And to analyze self-organizing clustering method, study For wireless sensor network configuration in ship.

• Journal of Ginseng Research
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• v.39 no.4
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• pp.406-413
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• 2015

Background: Pathogenesis-related 10 (PR-10) proteins are small, cytosolic proteins with a similar three-dimensional structure. Crystal structures for several PR-10 homologs have similar overall folding patterns, with an unusually large internal cavity that is a binding site for biologically important molecules. Although structural information on PR-10 proteins is substantial, understanding of their biological function remains limited. Here, we showed that one of the PgPR-10 homologs, PgPR-10.3, shares binding properties with flavonoids, kinetin, emodin, deoxycholic acid, and ginsenoside Re (1 of the steroid glycosides). Methods: Gene expression patterns of PgPR-10.3 were analyzed by quantitative real-time PCR. The three-dimensional structure of PgPR-10 proteins was visualized by homology modeling, and docking to retrieve biologically active molecules was performed using AutoDock4 program. Results: Transcript levels of PgPR-10.3 expressed in leaves, stems, and roots of 3-wk-old ginseng plantlets were on average 86-fold lower than those of PgPR-10.2. In mature 2-yr-old ginseng plants, the mRNA of PgPR-10.3 is restricted to leaves. Ginsenoside Re production is especially prominent in leaves of Panax ginseng Meyer, and the binding property of PgPR-10.3 with ginsenoside Re suggests that this protein has an important role in the control of secondary metabolism. Conclusion: Although ginseng PR-10.3 gene is expressed in all organs of 3-wk-old plantlets, its expression is restricted to leaves in mature 2-yr-old ginseng plants. The putative binding property of PgPR-10.3 with Re is intriguing. Further verification of binding affinity with other biologically important molecules in the large hydrophobic cavity of PgPR-10.3 may provide an insight into the biological features of PR-10 proteins.

• Journal of Ginseng Research
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• v.44 no.2
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• pp.215-221
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• 2020

Background: Panax ginseng has been used for a variety of medical purposes in eastern countries for more than two thousand years. From the extensive experiences accumulated in its long medication use history and the substantial strong evidence in modern research studies, we know that ginseng has various pharmacological activities, such as antitumor, antidiabetic, antioxidant, and cardiovascular system-protective effects. The active chemical constituents of ginseng, ginsenosides, are rich in structural diversity and exhibit a wide range of biological activities. Methods: Ginsenoside constituents from P. ginseng flower buds were isolated and purified by various chromatographic methods, and their structures were identified by spectroscopic analysis and comparison with the reported data. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H- tetrazolium bromide method was used to test their cytotoxic effects on three human cancer cell lines. Results: Six ginsenosides, namely 6'-malonyl formyl ginsenoside F₁ (1), 3β-acetoxyl ginsenoside F₁ (2), ginsenoside Rh₂₄ (6), ginsenoside Rh₂₅ (7), 7β-hydroxyl ginsenoside Rd (8) and ginsenoside Rh₂₆ (10) were isolated and elucidated as new compounds, together with four known compounds (3-5 and 9). In addition, the cytotoxicity of these isolated compounds was shown as half inhibitory concentration values, a tentative structure-activity relationship was also discussed based on the results of our bioassay. Conclusion: The study of chemical constituents was useful for the quality control of P. ginseng flower buds. The study on antitumor activities showed that new Compound 1 exhibited moderate cytotoxic activities against HL-60, MGC80-3 and Hep-G2 with half inhibitory concentration values of 16.74, 29.51 and 20.48 μM, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.6
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• pp.1010-1024
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• 2016

This study identifies the influence of on/off-line acquaintances' recommendation messages on fashion product attitude and purchase intention on the online purchase of fashion products in two-sided word of mouth situations as well as compares the difference in influence according to bond-base with equidistance. This study was conducted for one month on university students in their 20s who were believed to be active in smartphone use. Out of the collected 174 copies of the questionnaire, 162 copies were used for analysis. The questionnaire was classified into online and offline recommendation messages of an acquaintance. We present two-sided fashion product reviews made similar to the type found in an actual shopping mall web-site. As for analysis, confirmatory factory analysis, structural equation modeling, and multi-group analysis were conducted using AMOS 19.0. The analysis results are as follows. First, on/off-line acquaintances' recommendation messages had significant influences on product attitude in the situation where two-sided reviews on fashion products were presented; however, those messages did not influence purchase intention. Recommendation messages positively increased product attitude and enhanced purchase intention if acquaintances' recommendation messages were mediated between on/off-line acquaintances' recommendation messages and purchase intention. Consequently, a mediating effect on product attitude was revealed. Second, there was no difference between online acquaintances and offline acquaintances in terms of the influence of acquaintances' recommendation messages on product attitude and purchase intention, in the situation where two-sided reviews were presented on online fashion products. Therefore, no control effect according to the type of acquaintance was confirmed.

• The Korean Journal of Franchise Management
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• v.7 no.1
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• pp.13-20
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• 2016

Purpose - In the past, the chain hotel chefs only serve food to their customers. However recently, the hotel chefs play a pivotal role in hotel including considering various customer preferences, safety and nutrition of food, and increasing profits through effective human resource management and inventory control. With the change of the chain hotel chef's' roles, pygmalion leadership, one of new leadership styles, focuses on the effect that leader's positive expectation let subordinates have motivation and more engage in work. This study investigates the effect of chain hotel chef's pygmalion leadership on leader trust and organizational trust. Research design, data, and methodology - This study was to investigate the structural relationships among chain hotel restaurant chefs' pygmalion leadership, hotel restaurant cooks' leader trust, organizational trust, and teamwork, and how leader trust and organizational trust play mediating roles in the relationship between pygmalion leadership and teamwork. In this model, pygmalion leadership includes 4 dimensions: Climate, Feedback, Input, and Output. Data were collected using self-administered questionnaire survey on cooks of Deluxe hotel restaurants located in Seoul and Gyonggi-Do. The samples for data analyses were 243 excepting unusable responses. Result - The findings can be summarized as follows: First, climate and feedback had a positive effect on leader trust, respectively. Second, feedback and output had a statistically positive effect on organizational trust, respectively. Third, leader trust had positive effects on organizational trust and teamwork. Fourth, organizational trust had a significant effect on teamwork. Conclusions - As a chain hotel chef treats his/her staffs sincerely, they will be more engaged in work by establishing trust in their leader. Ultimately, it leads to higher sales profit and customer satisfaction. In addition, a hotel can encourage chefs and other staffs to treat each other as if the student-instructor relations, not just commanding staffs. Then, cooks build up their trust to their leader and organization for its sustained growth and development, and the internal bond in organization including teamwork is strengthened. Therefore, to strengthen teamwork and organizational trust, there should be active communication, knowledge sharing, goal sharing, and cooperation between chefs and cooks.

• The korean journal of orthodontics
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• v.20 no.3 s.32
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• pp.447-462
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• 1990

The objective of this experiment is to observe structural differences in the othodontic movement of vital (control group) and devitalized (experimental group) teeth in the mongrel dogs. The 5 utilized dogs in this experiment were approximately 1 year of age and their average weight was about 12 Kg. Endodontic therapy was performed on the 2nd premolars in upper & lower jaws of each animal under the general anesthesia by intravascular injection of 25mg/kg of pentobarbital sodium. The canals of the teeth were obturated by using gutta percha in conjunction with root canal sealer (AH26 Densply). One of the roots in the 2nd premolars was hemisected to make an extraction space for the devitalized teeth to be moved. The edgewise technique was employed for the movement of the teeth. Orthodontic models and intraoral roentgenograms were taken before and after orthodontic tooth movement. The open coil springs (.010 x .040) were used at interbraket space in order to provide equal forces (75gm) between the teeth in each arch wire. After 13 weeks of active orthodontic tooth movement, dogs were sacrified and the experimental results w ere examined through the intraoral radiography, microscopic examination and scanning electromicroscopic examination at the root sulfate. From the results of the study, the following conclusions may be drawn: The root resolution and cemental deposition were observed within the pressure and tension site in both group. 2. The root resorbed lacunae were observed in the cementum and/or into the dentin in both group. 3. The prominent osteoblastic activities were observed on the alveolar margin in the tension site in both group. 4. A few of blood vessels were observed in the pressure site, but also lots of blood vessels were observed in the tension site especially in the periphery of the alveolar bone in both group. 5. In the pressure site, resorbed lacunae were formed with deep and narrow cavity in the control group; the shallow and wide cavity in the experimental group. 6. In the pressure site, the repaired cementum or cementoid tissue was lined on cementum in the experimental group, but not in the control group. 7. There was no significant difference between external root resolution of endodontically and vital teeth when both were subjected to orthodontic forces.