• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.485-491
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• 2014

In this paper, it is proposed that the effects of simulator sickness due to scene movement in ship handling simulator can be measured by using center of pressure (COP) and a simulator sickness questionnaire (SSQ). For experiments of simulator sickness, twelve participants are exposed to scenes movement from ship handling simulator according to three steps of sea states. During experiments, COPs for subjects are measured by force plate. After exposure to scenes movement, subjects describe their sickness symptoms by answering the SSQ. Throughput analysing the results of scene movement, SSQ, and COP, the relation between the simulator sickness and COP is investigated. It is suggested that formulations for SSQ score and COP with respect to sea state are obtained by the curve fitting technique, and the longitudinal COP can be used for measuring the simulator sickness.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.10-18
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• 2019

The Interior finishing materials tried to evaluate the combustion characteristics and the dangerous characteristic of Floor finish and Wall finish. We often use, conducting the experiment ISO 5660-1, Cone Calorimeter method, and ISO-TR-9122 FT-IR. According to the result of Cone calorimeter experiment, the tile carpet FF3 of Floor material had the highest THR $74.6mj/m^2$ because of the highest risk, and the PHRR of FF1 was $726kW/m^2$, which was easy to bum. As a result FT-IR test, The CO, $CO_2$ ratio was 8,146 PPM for roll carpet FF1 than tile carpet FF2, FF3 5,996, 5,171 PPM, which was a carpet with a high toxicity risk. In the case of wall finishes, The MDF plate(WF3) was THR $86.7mj/m^2$ with a high risk, PHRR $384kW/m^2$ was easy to ignite and toxicity index was 5.5. The CO, $CO_2$ ratio was 1,340~8,596 PPM, But the WF4 was the most toxic with 8,596 PPM.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.889-901
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• 2021

The tension of cables and motion response significantly affect safety of an immersed tunnel element in the immersion process. To investigate those, a hydrodynamic scale-model test was carried out and the model experiments was conducted under wind, current and wave loads simultaneously. The immersion standby (the process that the position of the immersed tunnel element should be located before the immersion process) and immersion process conditions have been conducted and illustrated. At the immersion standby conditions, the maximum force of the cables and motion is much larger at the side of incoming wind, wave and current, the maximum force of Element-6 (6 cables directly tie on the element) is larger than for Pontoon-8 (8 cables tie on pontoon of the element), and the flexible connection can reduce the maximum force of the mooring cables and motion of element (i.e. sway is expecting to decrease approximate 40%). The maximum force of the mooring cables increases with the increase of current speed, wave height, and water depth. The motion of immersed tunnel element increases with increase of wave height and water depth, and the current speed had little effect on it. At the immersion process condition, the maximum force of the cables decrease with the increase of immersion depth, and dramatically increase with the increase of wave height (i.e. the tension of cable F4 of pontoons at wave height of 1.5 m (83.3t) is approximately four times that at wave height of 0.8 m). The current speed has no much effect on the maximum force of the cables. The weight has little effect on the maximum force of the mooring cables, and the maximum force of hoisting cables increase with the increase of weight. The maximum value of six-freedom motion amplitude of the immersed tunnel element decreases with the increase of immersion depth, increase with the increase of current speed and wave height (i.e. the roll motion at wave height of 1.5 m is two times that at wave height of 0.8 m). The weight has little effect on the maximum motion amplitude of the immersed tunnel element. The results are significant for the immersion safety of element in engineering practical construction process.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.227-234
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• 2013

The purpose of the study is to realize and develop the healing process that applies the Forest Healing Program to complementary and alternative therapies within the integrated medical health care place call ' Healing Forest'. Various healing programs need to develope and distribute to educate tentatively name ' Forest Healing Instructor' whom will be the key roll player on the program. Hereupon, collected the feedback of the program from 20 of professors, health care professionals and complementary alternative related professionals who are deeply related on the dendrology using Delphi examine. The study suggests the professional, who knows on dendrology, base medicine knowledge and healing power, Forest Healing Instructor Course includes education and assessment method base on education subject, course complete scope, instructor curriculum, education goal and education operation process. The Journal of Digital Policy & Management. This space is for the of your study in English.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.257-262
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• 2013

A ship operating in rough sea may suffer from an undesirable motion which may severely degrade the performance of equipment onboard and give a person an uncomfortable feeling. Hence, roll stabilization received a considerable attention and various devices including bilge keels, stabilizing fins, gyroscopic, anti-rolling tanks, rudders and flaps have been conceived and utilized for the purpose. The Coanda effect is evident when a jet stream is applied tangential to a curved surface of a hydrofoil since then the jet increases the circulation around the foil and consequently the lift. Model tests and numerical simulation have been conducted to examine the practicality of a fixed type fin stabilizer augmented by the Coanda jet. The results show that the lift coefficient of the modified Coanda fin at the zero angle of attack identically coincides with that of the original fin at ${\alpha}=\26^{\circ}$ when Coanda jet is supplied at the rate of $C_j$ = 0.25. It is also shown that fixed type fin stabilizers for active control of the motions of ships and the other mobile units without rotation can be put to practical use if the Coanda effect is applied.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.2
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• pp.95-102
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• 2001

Nano-scale gate length MOSFET devices require extremely shallow source/drain eftension region with junction depth of 20∼30nm. In this work, 20nm $n^{+}$-p junctions that are realized by using this $As_{2}^{+}$ low energy ($\leq$10keV) implantation show the lower sheet resistance of the $1.0k\Omega$/$\square$ after rapid thermal annealing process. The $As_{2}^{+}$ implantation and RTA process make it possible to fabricate the nano-scale NMOSFET of gate length of 70nm. $As_{2}^{+}$ 5 keV NMOSFET shows a small threshold voltage roll-off of 60mV and a DIBL effect of 87.2mV at 100nm gate length devices. The electrical characteristics of the fabricated devices with the heavily doped and abrupt $n^{+}$-p junctions ($N_{D}$〉$10^{20}$$cm^{-3}$, $X_{j}$$\leq$20nm) suggest the feasibility of the nano-scale NMOSFET device fabrication using the $As_{2}^{+}$ low energy ion implantation.

• Geophysics and Geophysical Exploration
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• v.14 no.4
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• pp.298-304
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• 2011

We conducted magnetic survey using IBRV (Ice Breaker Research Vessel) ARAON of KORDI (Korea Ocean Research and Development Institute), ROV (Remotely Operated Vehicle) of Oceaneering Co. and three components vector magnetometer, at Apr., 2011 in the western slope of the caldera of TA25 seamount, the Lau Basin, the southwestern Pacific. The depth ranges of the survey area are from about 900 m to 1200 m, below sea level. For the deep sea magnetic survey, we made the nation's first small deep sea three components magnetometer of Korea. The magnetometer sensor and the data logger was attached with the upper part and lower part of ROV, respectively. ROV followed the planning tracks at 25 ~ 30 m above seafloor using the altimeter and USBL (Ultra Short Base Line) of ROV. The three components magnetometer measured the X (North), Y (East) and Z (Vertical) vector components of the magnetic field of the survey area. A motion sensor provided us the data of pitch, roll, yaw of ROV for the motion correction of the magnetic data. The data of the magnetometer sensor and the motion sensor were recorded on a notebook through the optical cable of ROV and the network of ARON. The precision positions of magnetic data were merged by the post-processing of USBL data of ROV. The obtained three components magnetic data are entirely utilized by finding possible hydrothermal vents of the survey area.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.11-23
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• 2006

This study was carried out to propose low types of green speed expectation models for fast putting green management by changing mowing height($4.0{\sim}2.5$ mm) and timing of rolling, dew removal and dew removal+rolling. Ball roll distance data were taken from the creeping bentgrass(Agrostis palustris Huds. 'Penncross') practice green of east course at the Lakeside C.C. in October 18, 2001 and May 25, 2002. Data were subjected to multi-regression analysis using Statistical Package for the Social Science. Among four types of green speed expectation models, the best multiple-regression equation for fast green management was as follows; $Y_4=4.171-0.225{\cdot}X_1-0.038{\cdot}X_2$ (where, $Y_4$ : green speed(m) after single dew removal+single rolling, $X_1$ : mowing height($4.0{\sim}2.5,\;X_2$ : passage of time ($0{\sim}8$ h.)). The equation[single dew removal by using sponge roller $\rightarrow$ single mowing at 3.0 mm height or less $\rightarrow$ single rolling] explained to provide fast green over 3.2 m (Stimpmeter readings required for USGA championship play) until the end of first round. Therefore, this cultural practice system was believed to provide fast putting green condition for professional golf tournament

• Resources Recycling
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• v.29 no.2
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• pp.28-36
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• 2020

To enhance the recycling rate of wasted glass bottles toward recycled aggregates, the study would decide optimal comminution equipment based on the particle size distribution, aspect ratio and equipment energy analysis. The impact, compress and abrasion is type of generated force by comminution. So, hammer crusher, shredder, roll crusher and ball mill have been selected because they have characteristic which is each type of force. As a result of the particle size analysis of each product, only the shredder product satisfied concrete and asphalt aggregate quality standard condition. Also, as a result of aspect ratio analysis using Imaging software program (Image J, National institute of health), most of size fraction is confirmed under 1.6 value. It was confirmed that the product has low dangerousness and satisfying to shpage index. Also, the particle reduction ratio against input energy of shredder product was the most high. Therefore, we can decide that the optimal equipment which applicable for comminuting waste glass bottle in certain particle size under 10mm is shredder. The result of study will make contribution to increasing energy efficiency of comminution processing and competitiveness of product.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2459-2467
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• 2010

The purpose of this study was to survey visiting health care personnel who worked for their public medical health institutions and thereby investigate their oral health knowledge and behavior. Findings of this study are summarized as follow; First, our visiting health care personnel had a significant tendency toward higher score at correct answers to questions about oral health knowledge (mean knowledge about periodontal disease: 67%, mean knowledge about dental caries: 68%, mean knowledge about common dentistry: 68.4% or higher). Secondly, in terms of oral health care behavior, 50% or higher of all our visiting health care personnel visited dental clinic for preventive purposes, and 60.1% visited dental clinic for oral treatment. 46.6% of health care personnel relied on dental clinic for regular scaling services, and 89.6% relied on general hospital or dental clinic for oral treatment. 89.5% of health care personnel brushed their teeth 3 times or more per day; more than half (58%) of them preferred dental floss to other oral hygiene supplies; and 46% practiced roll technique to brush their teeth. Thirdly, health care personnel's oral health knowledge was significantly correlated with their age (F=5.25, p<0.01) and career of health care (F=3.94, p<0.01), while their oral health behavior was significantly associated with their career of visiting health care (F=3.20, p< 0.05).