• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.6
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• pp.317-325
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• 2023

Background: Local anesthetic injections may induce pain in children, leading to fear and anxiety during subsequent visits. Among the various approaches recommended to reduce pain, one is the use of a Buzzy Bee^TM device that operates on the concept of gate control theory and distraction. The literature regarding its effectiveness during the deposition of local anesthesia remains limited; hence, the aim of the present study was to determine the efficacy of extraoral cold and vibrating devices in reducing pain perception during the deposition of local anesthesia. Methods: A split-mouth crossover study in which 40 children aged 3-12 years requiring maxillary infiltration or inferior alveolar nerve block for extractions or pulp therapy in the maxillary or mandibular posterior teeth were included. The control intervention involved the application of topical anesthetic gel for one minute (5% lignocaine gel), followed by the administration of local anesthetic (2% lignocaine with 1:80,000 adrenaline) at a rate of 1 ml/ minute. Along with the control protocol, the test intervention involved using the Buzzy Bee^TM device for 2 minutes before and during the deposition of the local anesthetic injection. The heart rate and face, legs, arms, cry, and consolability revised (FLACC-R) scale scores were recorded by the dentist to assess the child's pain perception. Results: The mean age of the participants in Group A and Group B was 7.050 ± 3.12 years and 7.9 ± 2.65 years respectively. A reduction in the mean heart rate and FLACC-R score was observed during the deposition of local anesthetic solution in the tissues when the Buzzy Bee^TM was used in both groups at different visits in the same subjects (P < 0.05) The Buzzy Bee^TM device was effective in reducing the heart rate and FLACC-R scores when used during maxillary infiltration and inferior alveolar nerve block local anesthesia techniques (P < 0.05). Conclusion: The use of extraoral cold and vibrating devices significantly reduces pain perception during local anesthetic deposition in pediatric patients. Considering the results of this study, the device may be incorporated as an adjunct in routine dental practice while administering local anesthesia in children.

• The Korean Journal of Physiology
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• v.1 no.2
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• pp.199-213
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• 1967

Circulatory and respiratory activities were observed in men exposed to the environment of engine room of a cruising Republic of Korea Navy ship and compared to the control values obtained in an ordinary laboratory room on land. The environment of an engine room of cruising navy ship was presumed to be a multiple stress acting on men. The environment of the engine room included high temperature $(35-42^{\circ}C)$, low relative humidity (20-38% saturation), vibration (about 7 cycles per second), rolling and pitching of ship and noises. Sixteen men were divided into two groups consisted of each 8 subjects. Subjects of sea duty group had experience of continuous on board duty averaging 3.5 years. Men of land duty group had no experience of on board activity. On land observations were made on one day prior to the boarding and leaving the port and four days after landing. In between observations in the engine room were made on the first, 5 th, 9 th, 12 th, and 14 th day of on board activity. The whole experimental period lasted for 20 days. Measurements on circulatory and respiratory parameters were at standing resting state (after 30 minutes standing in the case of on land study and 15 minutes in engine room study) and within one minute after cessation of on the spot running of which rhythm was 30/min. and lasted for 5 minutes. Oxygen consumption and pulmonary function test were done in the period of two minutes from the 3rd to 5th minutes of running. The following results were obtained. 1. Body temperature showed no change regardless of group difference or on land or on board measurements. 2. Pulse rate increased markedly after boarding the ship id both groups. Pulse rate increased from the first day on board at rest and after exercise as compared to the on land control value. This increase in pulse rate was more marked after exercise. Sea duty group showed less increase in pulse rate at rest than the land duty group. Standing and resting pulse rate of sea duty group on lam was 81 and increased to 87 at the 5th day on board and remained smaller than the land duty group throughout the period on board. Control standing and resting pulse rate of land duty group on land was 76 and reached 89 at the 9th day on board and thereafter decreased a little. Pulse rate of land duty group at rest on board remained greater than that of sea duty group throughout the period on board. 3. Systolic blood pressure of sea duty group increased after boarding the ship and remained higher than the control value on land. In the land duty group, however, systolic blood pressure decreased during the period on board the ship. Diastolic blood pressure decreased in both groups. 4. Resting breathing rate of land duty group increased and remained higher than the control value on land. In sea duty group, however, resting breathing rate showed a transient increase on the 1st day on board and decreased thereafter to the control value on land and kept the same level throughout the period of cruise. Absolute value of breathing rate in the sea duty group was greater than the land duty group both at rest and after exercise. 5. There was a lowering of breathing efficiency in both groups. Thus, increases in tidal volume and minute ventilation volume and decreases in maximum breathing capacity, vital capacity, capacity ratio and air velocity Index were observed after boarding the ship. An increase in ventilation equivalent was also observed in both groups. The lowering of breathing efficiency was more marked in the land duty group than the sea duty group. 6. Energy expediture increased in both groups during their stay on the ship and was more marked in the sea duty group. 7, Lactate concentration in venous blood at rest and after exercise increased after boarding the ship and no group difference was observed.

• Explosives and Blasting
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• v.32 no.2
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• pp.16-24
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• 2014

In this "Wonju~Jaecheon double-lanes railroad" project, a highway is located at about 13meter above a tunnel. Initially, rock-splitting method was used for the tunnel excavation in order to minimize the possible damage on the highway. The method, however, takes a long time for the tunnel excavation and that may cause other problems like large displacement of tunnel and subsidence of highway ground before the tunnel can be stabilized by supporters. Therefore, the application of electronic blasting method(eDdevII) was recommended to control the blast vibration below 1.0cm/sec as well as to prevent the subsidence of highway ground. The analysis of the influence of tunnel excavation on the highway showed that electric blasting method is permissible for the safe management of the highway. Based on that, the tunnel construction under a highway could be carried out quickly and safely without any damages on the highway.

• Earthquakes and Structures
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• v.3 no.2
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• pp.141-168
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• 2012

The Retrofit Yield Spectrum (RYS) is a new spectrum-based device that relates seismic demand of a retrofitted structure with the fundamental design parameters of the retrofit. This is obtained from superposition of Yield Point Spectra with design charts that summarize in pertinent spectrum-compatible coordinates the attributes of a number of alternative retrofit scenarios. Therefore, once the requirements for upgrading a given structure have been determined, the RYS enable direct insight of the sensitivity of the seismic response of the upgraded structure to the preliminary design decisions made while establishing the retrofit plan. By virtue of their spectrum-based origin, RYS are derived with reference to a single mode of structural vibration; a primary objective is to control the contribution of this mode in the retrofit design so as to produce a desirable distribution of damage at the ultimate limit state by removing soft storey formations and engaging the maximum number of structural members in deformation, in response to the input motion. Calculations are performed with reference to the yield-point, where secant stiffness is proportional to the flexural strength of reinforced concrete members. Derivation and use of the Retrofit Yield Spectra (RYS) refers to the seismic demand expressed either in terms of spectral acceleration, spectral displacement or interstory drift, at yield of the first storey. A reinforced concrete building that has been tested in full scale to a sequence of simulated earthquake excitations is used in the paper as a demonstration case study to examine the effectiveness of the proposed methodology.

• The Journal of the Acoustical Society of Korea
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• v.32 no.1
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• pp.43-55
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• 2013

The window ventilation system based on the heat recovery device was developed which make air ventilation possible without opening the windows. However, mechanical and aerodynamic noises were come to pass which annoyed people in rooms. In the present study, noise of new window ventilation system was measured in both general room and anechoic chamber. Also, the noise path was detected to find cause of noise generation and vulnerable area of the device. Sound absorptive and insulation materials were applied to mitigate the noise. Finally, an alternative noise control method was suggested which can satisfy with the indoor noise standards. As a result, it was shown that the cause of noise was the low transmission loss in the ventilation system. As a result, it was shown that the main noise source of the ventilation system was the blower and the major cause of noise was the low transmission loss of the ventilation system. It is also concluded that the noise levels complies with the noise standards of 40 dBA when 2 mm rubber sheet is applied inside the ventilation system.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.1-8
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• 2020

The aeroservoelastic analysis that deals with the interactions of the inertial, elastic, and aerodynamic forces and the influence of the control system have been performed. MSC Nastran was used for the free vibration analysis of the structure model as the pre-analysis. ZAERO was used to calculate the unsteady aerodynamic forces. The unsteady aerodynamic forces were verified by comparing with Doublet Hybrid Method. Karpel's Minimum-State Approximation method was used for approximation of the aerodynamic forces to the Laplace domain in the frequency domain. The aeroservoelastic state-space equation was obtained by combining the aeroelastic equation with the actuator dynamics. The analysis of aeroservoelastic stability concerning the elevator input of the high aspect ratio model was performed. The root-locus method and time-integration method were used for the analysis of aeroservoelastic in frequency and time domain.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1732-1737
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• 2004

This paper proposes Internet-based checking technique for machine-tools with variant CNC (Computerized Numerical Controller). According to the architecture of CNC, CNC is classified into two types such as CAC (Closed Architecture Controller) which is conventional CNC, and OAC (Open Architecture Controller) which is a recently introduced PC-based controller. CAC has a closed architecture and it is dependent on CNC vender specification. Because of this, it has been very difficult for users to implement an application programs in CNC domain. Therefore, an additionally special module is required for Internet-based application such as remote checking. In this case, web I/O embedded module can be efficiently applied for Internet-based checking. The module is directly attached to TCP/IP network for communication. In order to obtain the monitoring data of CNC machines, the I/O signals of the module are assigned to PLC (Programmable Logic Controller) input and output (I/O) signals within CNC domain. On the other hand, OAC has a PC-based open architecture and an additional module is not necessary for the connection with external site. Because of this, a simple DAU is just used for signal sensing and data acquisition without additional communication modules. For Internet-based remote checking of machine-tools with OAC, a user-defined daemon and application programs are implemented as the form of internal function within the PC-based controller. Internet communication is performed between the daemon program in CNC domain and web script programs in external server. Checking points defined in this research are classified into two categories such as structured point and operational point. The formal includes the vibration of bearing, temperature of spindle unit and another periodical management. And the latter includes oil checking, clamp locking/unlocking and machining on/off status.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.4
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• pp.435-443
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• 2010

This study presents key parameters for the structure installed with MR controller in reducing its responses. MR controller is regarded as Bingham model of which control forces are frictional and viscous ones. The parameters are identified as friction force ratios, $R_f$ and $R_h$ which are, respectively, ratio of MR controller friction force to static restoring force for free vibration and ratio of the friction force to amplitude of harmonic force. Structure-MR controller system shows nonlinear response behavior due to friction force. Energy balance strategy is adopted to transform the behavior to linear one with equivalent damping ratio. Finally, proposed equivalent linear process is compared to the nonlinear one, which turns out to give acceptably good results.

• Ocean and Polar Research
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• v.42 no.2
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• pp.171-178
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• 2020

R/V EARDO, commissioned in 1992, has successfully carried out ocean research campaigns in Korean jurisdictional and adjacent waters, including continental margins and coastal zones within the Korean Exclusive Economic Zone (EEZ), for 29 years. However, it will soon be reaching the end of its useful service life. A replacement for R/V EARDO is urgently needed to ensure the safety of vessel itself and its crews, and efficient ship operation and maintenance, as well as to meet modern scientific mission requirements (SMRs). Basic specifications for a replacement ship have been devised and reviewed over the past nine months. A test of the proposed hull form was also performed. The total tonnage of the proposed vessel is approximately 740 tons, and the overall length and width are 62.0 and 11.6 m, respectively. The new ship will thus be 73% larger than the current R/V EARDO; in particular, the research workspace will be 4.4 times larger. The major design priorities are the propulsion system, efficiency of radiated noise and vibration control, and the dynamic positioning system. An environmentally friendly emission system, meeting International Maritime Organization (IMO) Tier III regulations, will be installed in the third exhaust pipe. Various wet and dry lab spaces as well as 32 different scientific instruments have also been considered in the ship design.

• Smart Structures and Systems
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• v.15 no.2
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• pp.355-373
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• 2015

An optimal sensor placement (OSP) method based on structural subsection technique (SST) and model reduction technique was proposed for modal identification of truss structures, which was conducted using genetic algorithm (GA). The constraints of GA variables were determined by SST in advance. Subsequently, according to model reduction technique, the optimal group of master degrees of freedom and the optimal objective function value were obtained using GA in a case of the given number of sensors. Correspondingly, the optimal number of sensors was determined according to optimal objective function values in cases of the different number of sensors. The proposed method was applied on a scaled jacket offshore platform to get its optimal number of sensors and the corresponding optimal sensor layout. Then modal kinetic energy and modal assurance criterion were adopted to evaluate vibration energy and mode independence property. The experiment was also conducted to verify the effectiveness of the selected optimal sensor layout. The results showed that experimental modes agreed reasonably well with numerical results. Moreover the influence of the proposed method using different optimal algorithms and model reduction technique on optimal results was also compared. The results showed that the influence was very little.