• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.77-86
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• 2013

Laboratory pullout tests were conducted to evaluate pullout performance of steel strip reinforcements with deformed steel bars as transverse members. The steel strip reinforcement has an installation hole to assemble a deformed steel bar. Jumunjin standard sand is used to form a relative density of ground model to 80%. Frictional resistance of steel strip reinforcement without transverse member increases sharply at the initial displacement and quickly decreases with displacement. Maximum frictional resistance increases linearly as normal pressure increasing, and soil-reinforcement interaction friction angle(${\rho}_{peak}$) of a steel strip reinforcement is estimated to $14.64^{\circ}$. Passive resistance increases with displacement and converge into maximum passive resistance in most cases. Maximum passive resistance increases linearly as normal pressure increasing irrespective of shape of the steel reinforcement. Pullout force of steel strip reinforcements with installation holes or transverse members largely increases about 4 to 7 times compared to frictional resistance force of steel strip reinforcements when embedment length($L_e$) of steel strip reinforcements is 500 mm. In the case of using 2 transverse members, interference effect is observed due to the spacing of 2 transverse members and location of assembly holes and transverse members.

• Journal of the Korean Vacuum Society
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• v.20 no.5
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• pp.361-366
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• 2011

An in-situ, real-time monitoring of GaN epilayers grown by low pressure metalorganic chemical vapor deposition system modified for spectral reflectance was performed. Reflectance spectrums from 190~861 nm were observed using p-polarized light with incident angle of $75^{\circ}$. All reflectance spectrums showed interference oscillation caused by multiple reflection within GaN epilayers, and the spectrum from GaN with low crystalline quality showed weak reflectance intensity and much low amplitude of the oscillation because many defects in GaN resulted in light scattering and absorption. Signal variation of reflected light which was selected around strong constructive wavelength range was also observed during $NH_3$ supplying and $NH_3$ cut-off. There was no significant change in signal intensity when $NH_3$ cut-off for 10 sec, but it showed higher intensity when $NH_3$ was cut off for over 30 sec and its intensity kept unchanged. This result indicates that GaN surface was N-terminated during $NH_3$ supplying but Ga-terminated during $NH_3$ cut-off because of high nitrogen equilibrium vapor pressure of GaN, and metallic Ga-terminated surface caused slightly higher reflectance intensity.

• Wind and Structures
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• v.27 no.1
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• pp.11-27
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• 2018

The straight-cone steel cooling tower is a novel type of structure, which has a distinct aerodynamic distribution on the internal surface of the tower cylinder compared with conventional hyperbolic concrete cooling towers. Especially in the extreme weather conditions of strong wind and heavy rain, heavy rain also has a direct impact on aerodynamic force on the internal surface and changes the turbulence effect of pulsating wind, but existing studies mainly focus on the impact effect brought by wind-driven rain to structure surface. In addition, for the indirect air cooled cooling tower, different additional ventilation rate of shutters produces a considerable interference to air movement inside the tower and also to the action mechanism of loads. To solve the problem, a straight-cone steel cooling towerstanding 189 m high and currently being constructed is taken as the research object in this study. The algorithm for two-way coupling between wind and rain is adopted. Simulation of wind field and raindrops is performed with continuous phase and discrete phase models, respectively, under the general principles of computational fluid dynamics (CFD). Firstly, the rule of influence of 9 combinations of wind sped and rainfall intensity on flow field mechanism, the volume of wind-driven rain, additional action force of raindrops and equivalent internal pressure coefficient of the tower cylinder is analyzed. On this basis, the internal pressures of the cooling tower under the most unfavorable working condition are compared between four ventilation rates of shutters (0%, 15%, 30% and 100%). The results show that the 3D effect of equivalent internal pressure coefficient is the most significant when considering two-way coupling between wind and rain. Additional load imposed by raindrops on the internal surface of the tower accounts for an extremely small proportion of total wind load, the maximum being only 0.245%. This occurs under the combination of 20 m/s wind velocity and 200 mm/h rainfall intensity. Ventilation rate of shutters not only changes the air movement inside the tower, but also affects the accumulated amount and distribution of raindrops on the internal surface.

• Korean Journal of Psychosomatic Medicine
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• v.21 no.2
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• pp.140-146
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• 2013

Objectives: We compared the characteristics of the pain threshold and pain experience between demented group and non-demented group. Methods: This study was part of Gangwon projects for early detection of dementia in 2010. We recruited 8302 local resident ages over 65 years old. Of theses, 1259 people who scored low MMSE were selected and 365 of them completed CERAD-K(Consortium to Establish a Registry for Alzheimer's disease). Finally, 90 in non-demented group and 57 in demented group(mild to moderate Alzheimer's disease) were analyzed. Pain threshold was experimentally measured by pressure algometer and we investigated the pain experience, by Brief pain inventory (BPI), a self-report test. Results: In the demographic characteristics, there are more female, higher ages, lower education in the demented group. There was no significant difference between the two groups in the pain threshold. On the BPI results, 'shoulder pain', 'the number of pain' and 'interference of working' were significantly more prevalent in non-demented group. However, there are no significant differences between the groups in the 'pain severity', 'prevalence of pain' and 'pain treatment'. Conclusions: Demented group report less pain experience but, still perceived pain. It support previous studies that patient with dementia have increased pain tolerance but preserved pain threshold. Thus, active pain assessment and treatment for patients with dementia is needed.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.77-77
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• 1998

Present silicon dioxide (SiOz) 떠m as intennetal dielectridIMD) layers will result in high parasitic c capacitance and crosstalk interference in 비gh density devices. Low dielectric materials such as f f1uorina뼈 silicon oxide(SiOF) and f1uoropolymer IMD layers have been tried to s이ve this problem. I In the SiOF ftlm, as fluorine concentration increases the dielectric constant of t뼈 film decreases but i it becomes unstable and wa않r absorptivity increases. The dielectric constant above 3.0 is obtain어 i in these ftlms. Fluoropolymers such as polyte$\sigma$따luoroethylene(PTFE) are known as low dielectric c constant (>2.0) materials. However, their $\alpha$)Or thermal stability and low adhesive fa$\pi$e have h hindered 야1리ru뚱 as IMD ma따"ials. 1 The concept of a plasma processing a찌Jaratus with 비gh density plasma at low pressure has r received much attention for deposition because films made in these plasma reactors have many a advantages such as go여 film quality and gap filling profile. High ion flux with low ion energy in m the high density plasma make the low contamination and go어 $\sigma$'Oss피lked ftlm. Especially the h helicon plasma reactor have attractive features for ftlm deposition 야~au똥 of i앙 high density plasma p production compared with other conventional type plasma soun:es. I In this pa야Jr, we present the results on the low dielectric constant fluorocarbonated-SiOF film d밑JOsited on p-Si(loo) 5 inch silicon substrates with 00% of 0dFTES gas mixture and 20% of Ar g gas in a helicon plasma reactor. High density 띠asma is generated in the conventional helicon p plasma soun:e with Nagoya type ill antenna, 5-15 MHz and 1 kW RF power, 700 Gauss of m magnetic field, and 1.5 mTorr of pressure. The electron density and temperature of the 0dFTES d discharge are measUI벼 by Langmuir probe. The relative density of radicals are measured by optic허 e emission spe따'Oscopy(OES). Chemical bonding structure 3I피 atomic concentration 따'C characterized u using fourier transform infrared(FTIR) s야3띠"Oscopy and X -ray photonelectron spl:’따'Oscopy (XPS). D Dielectric constant is measured using a metal insulator semiconductor (MIS;AVO.4 $\mu$ m thick f fIlmlp-SD s$\sigma$ucture. A chemical stoichiome$\sigma$y of 야Ie fluorocarbina$textsc{k}$영-SiOF film 따~si야영 at room temperature, which t the flow rate of Oz and FTES gas is Isccm and 6sccm, res야~tvely, is form려 야Ie SiouFo.36Co.14. A d dielec$\sigma$ic constant of this fIlm is 2.8, but the s$\alpha$'!Cimen at annealed 5OOt: is obtain려 3.24, and the s stepcoverage in the 0.4 $\mu$ m and 0.5 $\mu$ m pattern 킹'C above 92% and 91% without void, res야~tively. res야~tively.

• Korean Journal of Community Nutrition
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• v.20 no.6
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• pp.433-446
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• 2015

Objectives: This study was performed to evaluate the consumer education program for reducing sodium intake based on social cognitive theory (SCT) and investigate consumer perceptions of environmental, cognitive and behavioral factors. Methods: Consumers (n=4,439) were recruited nationwide in Korea to participate in a nutrition education program for reducing sodium intake which was targeted on senior housewives (SH), parents (P), and office workers (OW). Questions regarding main factors of SCT were asked both before and after the education program. Results: SH and P recognized external social efforts and information to reduce sodium including nutrition labeling more than OW. The main barriers to practice reducing sodium intake were limited choice of low sodium food and menu, interference with social relationship when dining with others, and limited information, knowledge and skills. SH had lower barriers to practice reducing sodium intake and OW perceived 'preference to soup or stew' and 'preference to Kimchi, salted fish and fermented sauces' as barriers more than other groups at the baseline. Less than 50% of participants knew the relationship between sodium and salt, sodium in nutrition labeling, and recommended sodium intake. In addition, OW had little knowledge for capability to reduce sodium intake and lower self-efficacy to practice compared with SH and P. After education, positive outcome expectations such as lowering blood pressure, prevention of cardiovascular disease and osteoporosis were increased and barriers to practice reducing sodium intake were decreased in all groups (p < 0.05). The knowledge for behavioral capability and self-efficacy to reduce sodium intake were also improved but OW had still lower scores compared with other groups. Conclusions: These results suggested that nutrition education programs could be an effective tool to impact general population by facilitating awareness and increased capability to reduce sodium intake.

• Journal of the Korean Magnetics Society
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• v.17 no.2
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• pp.86-89
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• 2007

[ $FeCr_2Se_4$ ] prepared under the high pressure (3 GPa) has been studied with x-ray, neutron diffraction techniques, superconducting quantum interference device (SQUID) magnetometer, resistance, and Mossbauer spectroscopy. The temperature dependence of resistance is explained by Mott-VRH and small polaron model for the regions I (T<20 K) and II (T>42 K), respectively. Neutron diffraction results show an antiferromagnetic spin-lattice coupling near the Neel temperature. So finally the distance of atom is enlarged in region (110$FeCr_2Se_4$ shows convex type of temperature dependence.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.390-397
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• 2010

Residual solvents in foods are defined as organic volatile chemicals used or produced in manufacturing of extracts or additives, or functional foods. The solvents are not completely eliminated by practical manufacturing techniques and they also may become contaminated by solvents from packing, transportation or storage in warehouses. Because residual solvents have no nutritional value but may be hazardous to human health, there is a need to remove them from the final products or reduce their amounts to below acceptable levels. The purpose of this study was to develop and evaluate an analytical method for the screening of residual solvents in health functional foods. Furthermore, the aim of this study was to constitute a reasonable management system based on the current state of the market and case studies of foreign countries. Eleven volatile solvents such as MeOH, EtOH, trichloroethylene and hexane were separated depending on their column properties, temp. and time using Gas Chromatography (GC). After determining the GC conditions, a sample preparation method using HSS (Head Space Sampling) was developed. From the results, a method for analyzing residual solvents in health functional foods was developed considering matrix effect and interference from the sample obtained from the solution of solvents-free health functional foods spiked with 11 standards solutions. Validation test using the developed GC/HSS/MS (Mass Spectrometry) method was followed by tests for precision, accuracy, recovery, linearity and adequate sensitivity. Finally, examination of 104 samples grouped in suits was performed by the developed HSS/GC/MS for screening the solvents. The 11 solvents were isolated from health functional foods based on vapor pressure difference, and followed by separation within 15 minutes in a single run. The limt of detection (LOD), limit of quantification (LOQ), recovery and coefficient of variation (C.V.) of these compounds determined by the HSS/GC/MS were found to be 0.1 pg/mL, 0.1-125 pg/g, 51.0-104.6%, and less than 15%, respectively. Using the developed HSS/GC/MS method, residual solvent from 16 out of 104 health functional products were detected as a EtOH. This method therefore seems t o be a valuable extension ofanalytical method for the identification of residual solvents in health functional food.

• Journal of Korea Port Economic Association
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• v.35 no.4
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• pp.85-106
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• 2019

Offshore wind power is a representative renewable energy source and a rapidly growing industry. In Gyeongsangnam-do, offshore wind farms of 461.9MW are being pushed for in the Yokji island and are expected to expand further to over 1GW in the future. Accordingly, ports supporting the storage, assembly, transportation, and installation of offshore wind power equipment are expected to play an important role in the smooth progress of the offshore wind farm development project. Based on previous research and cases in major countries,this study prepared criteria for assessment of ports supporting offshore wind farmsand evaluated ports in Gyeongsangnam-do, which are linked to Yokji island offshore wind farms. The assessment criteria have been subdivided into distance from the offshore wind farm, port entry and exit restrictions, navigational areas, fishery rights factors, additional costs, berth length, depth of berth, size of the port yard, port berth bearing pressure, interference with other cargo, a civil appeal, and relevant industrial aggregation. The ports of Tongyeong, Samcheonpo, Kohyun, Masan, and Jinhae in Gyeongsangnam-do were selected and evaluated. As a result, the port of Tongyoung was superior in terms of distance from the Yokji island offshore wind farm. The ports of Samcheonpo, Masan, and Jinhae were evaluated as excellent in other criteria such as berth length, depth of berth, and so on. This study is expected to be used as a source of basic data for offshore wind power companies and policymakers to select and evaluate the supporting ports of offshore wind farms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4125-4130
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• 2015

This paper presents the communication performance for the radiation pattern reconfigurable antenna in the wearable device measuring bio signal (temperature, blood pressure, pulse etc.) of human body. The operational frequency is 2.4 - 2.5 GHz, which covers Bluetooth communication bandwidth. The maximum gain of the antennas is 1.96 dBi. The proposed antenna is efficiently transmitting and receiving signal by generating two opposite beam directions using two RF switches (PIN diode). Also, we investigated how radiation pattern changes according to three angles ($30^{\circ}$, $90^{\circ}$, $150^{\circ}$) of Top Loading. In this paper, we measured and compared the SNR (Signal-to-Noise Ratio) and BER (Bit Error Rate) performances of the proposed antennas in the condition between an ideal environment of anechoic chamber and smart house existing practical electromagnetic interferences (Universal Software Radio Peripheral, USRP). Throughout the comparing the results of the measurement of two cases, we found that the SNR is degraded over 5dB in average and BER is increased over ten times in maximum, therefore, it is confirmed that the error rate of receiving signal is increased. The measured results of SNR and BER value in this paper able to expect the performance degrading by the interference from the electromagnetic devices.