• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.331-338
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• 1995

Laserthermia is a new method of local hyperthermia using fiber optic guided probe with computer controlled Nd-YAG laser system. We used a synthetic sapphire probe and allowed irradiation with contolled low power laser energy (less than 5W), in different thermal condition (temprature: 38.5~50 degrees C) for 10 minutes, in the normal brain tissue of 18 rabbits. In results, the histological changes of brain tissue was variable (myelin condensation, chromatin condensation, nuclear waving and palisading, RBC discoloration, cell necrosis) in microscopic findings after laser irradiation, but changing area was not occured proportionally in thermal condition level. Cell necrosis appears to over 44.5 degrees C and the distance was about 1.25 mm. This study, using computer controlled laserthermia system for interstitial local hyperthermia, may offer many advantages in the experimental treatment and clinical management of tumor. Minimizing normal tissue damage is now being developed.

• International Journal of Computer Science & Network Security
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• v.21 no.6
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• pp.312-318
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• 2021

Lack of knowledge and digital skills is a threat to the information security of the state and society, so the formation and development of organizational culture of information security is extremely important to manage this threat. The purpose of the article is to assess the state of information security of the state and society. The research methodology is based on a quantitative statistical analysis of the information security culture according to the EU-27 2019. The theoretical basis of the study is the theory of defense motivation (PMT), which involves predicting the individual negative consequences of certain events and the desire to minimize them, which determines the motive for protection. The results show the passive behavior of EU citizens in ensuring information security, which is confirmed by the low level of participation in trainings for the development of digital skills and mastery of basic or above basic overall digital skills 56% of the EU population with a deviation of 16%. High risks to information security in the context of damage to information assets, including software and databases, have been identified. Passive behavior of the population also involves the use of standard identification procedures when using the Internet (login, password, SMS). At the same time, 69% of EU citizens are aware of methods of tracking Internet activity and access control capabilities (denial of permission to use personal data, access to geographical location, profile or content on social networking sites or shared online storage, site security checks). Phishing and illegal acquisition of personal data are the biggest threats to EU citizens. It have been identified problems related to information security: restrictions on the purchase of products, Internet banking, provision of personal information, communication, etc. The practical value of this research is the possibility of applying the results in the development of programs of education, training and public awareness of security issues.

• Korean small business review
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• v.42 no.1
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• pp.1-17
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• 2020

As technology competition among companies has intensified, the importance of technology protection is increasing day by day. However, according to the status of technology leakage in Korea, the technology protection level of SMEs is weak. SMEs' technology leakage continues to occur, and the damage can be even more serious to SMEs. Thus, the government is operating various support systems for SMEs. However, despite the support system, the interest and use of SMEs is low. This study examines the current status of major support systems for SME technology protection in Korea, and empirically analyzes the recognition and expectation effects of companies on the support systems. Based on the results, this study discusses ways to improve the recognition and use of the support system. The results of this study will contribute to strengthening SMEs 'technology protection by increasing the utility and enhancing the utilization of the support systems.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.91-99
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• 2022

By applying METHOD 514.8 of the US military standard MIL-STD-810H, vibration analysis of the winding core automatic feeding device was performed during vehicle transportation. The contact point between the LM guide and main support frame was weak in the vertical axis, transverse axis, and longitudinal axis during the transportation of the automatic winding core feeder vehicle, and the maximum equivalent stress was 236.31 MPa in the longitudinal axis. When random vibration was applied, the safety margin in the longitudinal direction was 0.26, indicating low safety. The safety margin was changed by increasing the damage factor to 0.1. Finally, the safety margin was improved to 3.48 to secure safety. Resonance occurred with a Q factor of 9.34 in the harmonic response to which the RMS value of the ASD data was input, and the vertical axis safety margin was derived as 0.16. When the damping factor was 0.15, the Q factor was 3.37, and resonance was avoided with a safety margin of 6.62.

• Earthquakes and Structures
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• v.23 no.3
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• pp.271-282
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• 2022

Seismic resisting self-centering bridge piers with high energy dissipation and negligible residual displacement after an earthquake event are focus topics of current structural engineering. The energy dissipation components of typical bridge piers are often relatively single; and exhibit a certain level of damage under earthquakes, leading to large residual displacements and low cumulative energy dissipation. In this paper, a novel socket self-centering bridge pier with a hybrid energy dissipation system is proposed. The seismic resilience of bridge piers can be improved through the rational design of annular grooves and rubber cushions. The seismic response was evaluated through the finite element method. The effects of rubber cushion thickness, annular groove depth, axial compression ratio, and lateral strength contribution ratio of rubber cushion on the seismic behavior of bridge piers are systematically studied. The results show that the annular groove depth has the greatest influence on the seismic performance of the bridge pier. Especially, the lateral strength contribution ratio of the rubber cushion mainly depends on the depth of the annular groove. The axial compression ratio has a significant effect on the ultimate bearing capacity. Finally, the seismic design method is proposed according to the influence of the above research parameters on the seismic performance of bridge piers, and the method is validated by an example. It is suggested that the range of lateral strength contribution ratio of rubber cushion is 0.028 ~ 0.053.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.206-219
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• 2021

The warming of the climate is increasing the damage caused by termites to wooden buildings, cultural properties and houses. A group removal system can be installed around the building to detect and remove termite damage; however, if the site is not visited regularly, every one to two months, you cannot observe whether termites have spread within, and it is difficult to take prompt effective action. In addition, since the system is installed and operated in an exposed state for a long period of time, it may be ineffective or damaged, resulting in a loss of function. Furthermore if the system is installed near a cultural site, it may affect the aesthetic environment of the site. In this study, we created a detection system that uses wood, cellulose, magnets, and magnetic sensors to determine whether termites have entered the area. The data was then transferred to a low power LoRa Network which displayed the results without the necessity of visiting the site. The wood was made in the shape of a pile, and holes were made from the top to the bottom to make it easier for termites to enter and produce a cellulose sample. The cellulose sample was made in a cylindrical shape with a magnet wrapped in cellulose and inserted into the top of a hole in the wood. Then, the upper part of the wood pile was covered with a stopper to prevent foreign matter from entering. It also served to block external factors such as light and rainfall, and to create an environment where termites could add cellulose samples. When the cellulose was added by the termites, a space was created around the magnet, causing the magnet to either fall or tilt. The magnetic sensor inside the stopper was fixed on the top of the cellulose sample and measured the change in the distance between the magnet and the sensor according to the movement of the magnet. In outdoor experiments, 11 cellulose samples were inserted into the wood detection system and the termite inflow was confirmed through the movement of the magnet without visiting the site within 5 to 17 days. When making further improvements to the function and operation of the system it in the future, it is possible to confirm that termites have invaded without visiting the site. Then it is also possible to reduce damage and fruiting due to product exposure, and which would improve the condition and appearance of cultural properties.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.189-196
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• 2020

We have developed a device for recording biological data by inserting three electrodes and a needle with an angular velocity sensor into the moth for the purpose of measuring the electromyogram of the flapping and the corresponding lift force. With this measurement, it is possible to evaluate the moth-physiological function of moths, and the amount of pesticides that insects are exposed to (currently LD50-based standards), especially the amount of chronic low-concentration exposure, can be reduced the dose. We measured and recorded 2-channel electromyography (EMG) and angular velocity corresponding to pitch angle (pitch-like angle) associated with wing flapping for 100 sweet potato hawkmoths (50 females and 50 males) with the animals suspended and constrained in air. Overall, the angular velocity and amplitude of EMG signals demonstrated high correlation, with a correlation coefficient of R = 0.792. In contrast, the results of analysis performed on the peak-to-peak (PP) EMG intervals, which correspond to the RR intervals of ECG signals, indicated a correlation between ΔF fluctuation and angular velocity of R = 0.379. Thus, the accuracy of the regression curve was relatively poor. Using a DC amplification circuit without capacitive coupling as the EMG amplification circuit, we confirmed that the baseline changes at the gear change point of wing flapping. The following formula gives the lift provided by the wing: angular velocity × thoracic weight - air resistance - (eddy resistance due to turbulence). In future studies, we plan to attach a micro radio transmitter to the moths to gather data on potential energy, kinetic energy, and displacement during free flight for analysis. Such physiological functional evaluations of moths may alleviate damage to insect health due to repeated exposure to multiple agrochemicals and may lead to significant changes in the toxicity standards, which are currently based on LD50 values.

• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.25-35
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• 1994

Many nephrotoxic agents exert their effect primarily on the cells of the proximal tubules. We used the LLC-$PK_1$, kidney epithelial cell line as a model system for studies on nephrotoxicity and investigated whether the uptake of $\alpha$-methylglucose($\alpha$-MG) could serve as a parameter to assess effects of nephrotoxicants on the functional integrity of the cells at an early time of toxicity. The enzyme leakage test which has been used to be as a conventional cytotoxic parameter in vitro, was conducted to compare with $\alpha$-MG uptake. Treatment with cisplatin for 24 and 48 hours significantly increased activities of lactate dehydrogenase and $\gamma$-glutamyltransferase in culture medium at a concentration of 50$\mu$M. However, above 100$\mu$M of concentration, activities of these enzymes in media were dramatically decreased by cisplatin. These observations indicate that cisplatin has direct inhibitory effect on the activities of these enzymes and make it doutful to use enzyme leakage test to demonstrate damage of kidney cells by chemicals such as cisplatin over the appropriate range of concentration. Cisplatin inhibited $\alpha$-MG uptake at a low concentration which enzymes were not leaked. Also cadmium chloride and mercuric chloride which are acutely nephrotoxic in vivo, significantly inhibited $\alpha$-MG uptake at a low concentration. These results indicate that the uptake of $\alpha$-methylglucose in LLC-$PK_1$cell line is a useful biomarker for the study of nephrotoxicity.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.313-320
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• 2011

The oxidative stress level and antioxidant activities in two green algae (Ulva pertusa and Ulva linza), two brown algae (Agarum cribrosum and Dictyota dichotoma), and three red algae (Grateloupia lanceolata, Carpopeltis affinis, and Gracilaria verrucosa) collected from intertidal regions of Korea were assessed. In the two green algae, although the total glutathione content was not as high as that of the brown algae, the glutathione pool was extremely reduced, and the glutathione reductase (GRd)/glutathione peroxidase (GPx) activity ratio was high, which apparently plays an important role for protection against oxidative damage, as manifested by low lipid peroxidation. In the brown algae, which exhibited a low lipid peroxidation level that was comparable to the green algal species, the highest glutathione content, together with high GPx activity, appears to be the most important factor in their antioxidant protection. The red algal species exhibited extremely high lipid peroxidation levels. They also contained the lowest and most oxidized glutathione among the species, as well as the lowest GRd activity. In spite of the marked difference in the glutathione content, the significant difference in the activity of ${\gamma}$-glutamylcysteine ligase, the rate limiting enzyme for glutathione synthesis, among the species was not exhibited. Our results suggest that there is a significant difference in the levels of oxidative stress and antioxidant capacity among the algal species, and that the glutathione system, especially the efficiency of glutathione recycling, plays a vital role in antioxidative protection in algal species.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.4
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• pp.395-403
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• 2012

This is direct bonding many of the metal bumps between FPCB and HPCB substrate. By using an ultrasonic horn mounted on an ultrasonic bonding machine, it is possible to bond gold pads onto the FPCB and HPCB at room temperature without an adhesive like ACA or NCA and high heat and solder. This ultrasonic bonding technology minimizes damage to the material. The process conditions evaluated for obtaining a greater bonding strength than 0.6 kgf, which is commercially required, were 40 kHz of frequency; 0.6MPa of bonding pressure; and 0.5, 1.0, 1.5, and 2.0 s of bonding time. The peel off test was performed for evaluating bonding strength, which was found to be more than 0.80 kgf.