• The Journal of Korea Assosiation for Disability and Oral Health
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• v.12 no.2
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• pp.82-86
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• 2016

Lowe syndrome is X-linked gene disorder, characterized by cataracts, renal dysfunction and brain abnormalities. Oral healthcare of young patients with Lowe syndrome could be easily neglected due to the uncooperative behavior or other systemic condition of the child. We are presenting a case of successful treatment under general anesthesia with uncooperative child with Lowe syndrome. A 3-year old boy with Lowe syndrome visited Seoul National University Dental Hospital for multiple caries. He had been suffering from congenital cataract, medullary nephrocalcinosis and hypotonia. Multiple caries were observed from clinical and radiographic examination. Concerning behavior management problem and possibility of aspiration due to hypotonia, dental treatment under general anesthesia was planned. Left upper primary first molar was extracted to prevent further infection. Other teeth were treated with Stainless steel crown or composite resin restoration based upon the extent and the severity of dental caries. Under general anesthesia, dental procedure was carried out successfully and safely. Considering uncooperative behavior and other medical conditions of the patient, general anesthesia could be effective. Home oral care and periodic visit to dental clinic should be emphasized to the caregiver of patient with Lowe syndrome, considering the susceptibility of dental caries and other oral manifestation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.242-252
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• 2016

A process-based ecosystem model, BIOME-BGC, was applied to simulate seasonal and inter-annual dynamics of carbon and water processes for potential evergreen needleleaf forest (ENF) biome in Korea. Two simulation sites, Milyang and Unljin, were selected to reflect warm-and-dry and cool-and-wet climate regimes, where massive diebacks of pines including Pinus densiflora, P. koraiensis and P thunbergii, were observed in 2009 and 2014, respectively. Standard Precipitation Index (SPI) showed periodic drought occurrence at every 5 years or so for both sites. Since mid-2000s, droughts occurred with hotter climate condition. Among many model variables, Cpool (i.e., a temporary carbon pool reserving photosynthetic compounds before allocations for new tissue production) was identified as a useful proxy variable of tree carbon starvation caused by reduction of gross primary production (GPP) and/or increase of maintenance respiration (Rm). Temporal Cpool variation agreed well with timings of pine tree diebacks for both sites. Though water stress was important, winter- and spring-time warmer temperature also played critical roles in reduction of Cpool, especially for the cool-and-wet Uljin. Shallow soil depth intensified the drought effect, which was, however, marginal for soil depth shallower than 0.5 m. Our modeling analysis implicates seasonal drought and warmer climate can intensify vulnerability of ENF dieback in Korea, especially for shallower soils, in which multi-year continued stress is of concern more than short-term episodic stress.

• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.392-401
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• 1997

Generally working environment and worker's health status of small scale industries (SSI) which employ less than 50 workers are known to be poorer than those of large scale industries(LSI) which employ more than 500 workers. However, according to the analysis of occupational injuries in Korea, prevalence rate of occupational injuries of SSI was 3.1 times as high as LSI. But there was no difference in prevalence rate of occupational disease and werkers with suspected occupational disease(D1) between SSI and LSI. To confirm these two different facts, we surveyed working environment and worker's health status of SSI and LSI in Kyeungin industrial complex. Workers in SSI were 10,878 and workers in LSI were 8,291 and number of hazardous agents in SSI were 3,554 and those of LSI were 1,916. We found following results. First, proportion of male workers and workers who were less than 30 yens old and more than 50 yens old was higher in SSI compared to LSI. Second, worker in SSI had more liver disease, viral hepatitis, and pneumoconiosis than in LSI, and there were more worker with suspected occupational disease, general disease, and worker needed close observation in SSI. But these effects had not statistical significance under the condition controlled by age and sex with logistic regression. Third, the numbers measured for specific chemicals, organic solvents, and heavy metals in SSI was more than in LSI. However there was on difference in the excess rate of each hazardous agent between SSI and LSI. As the above results workers' health status in SSI was poorer than in LSI, but these results were mainly due to the population structure difference. Although there were some limitation of this study and problems of sensitivity and validity for periodic health examination and working environment evaluation method, the concept that working environment and worker's health status in SSI should be reviewed. In future the study that will reveal the real weak point of SSI should be performed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.5
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• pp.613-623
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• 2012

In this paper, we present an ultra miniaturized voltage tuned oscillator, with HMIC-type amplifier and phase shifter, using LTCC artificial dielectric resonator. ADR which consists of periodic conductor patterns and stacked layers has a smaller size than a dielectric resonator. The design specification of ADR is obtained from the design goal of oscillator. The structure of the ADR with a stacked circular disk type is chosen. The resonance characteristic, physical dimension and stack number are analyzed. For miniaturization of ADRO, the ADR is internally implemented at the upper part of the LTCC substrate and the other circuits, which are amplifier and phase shifter are integrated at the bottom side respectively. The fabricated ADRO has ultra small size of $13{\times}13{\times}3mm^3$ and is a SMT type. The designed ADRO satisfies the open-loop oscillation condition at the design frequency. As a results, the oscillation frequency range is 2.025~2.108 GHz at a tuning voltage of 0~5 V. The phase noise is $-109{\pm}4$ dBc/Hz at 100 kHz offset frequency and the power is $6.8{\pm}0.2$ dBm. The power frequency tuning normalized figure of merit is -30.88 dB.

• Membrane Journal
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• v.12 no.1
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• pp.8-20
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• 2002

In this study using $N_2$-back flushing, which wwas not the general back-flushing method of membranes, the discharged wastewater from a paper plant was filtrated by 4 kinds of tubular carbon ceramic ultrafiltration membranes. We could in vestigate effects of $N_2$-back flushing period, transmembrane pressure (TMP)and flow rate and find optimal operating conditions. The $N_2$-back flushing time (BT) was fixed at 40 sec, filtration times (FT) were changed in 4~32 min, TNP in $1.0~3.0kg_f/cm^2$ the flow celocities in 0.53~1.09cm/s. The optimal conditions were discussed in the viewpoints of dimensionless permeate flux ($J/J_0$), toal permeate volume ($V_T$) and resistance of membrane fouling ($R_f$). Optimal back-flushing period was BT/FT=0.167 (FT=8 min ), in which more $V_T$ was obtained than that in BT/FT=0.083 (FT=4 min) which was the most friquent back-flushing condition. Then rising TMP should increase the driving force, and more $V_T$ could be accumulated. And rising flow rate should decrease membrane fouling increase permeate flux, and more $V_T$could be produced. Average rejection rates of pollutants were higher than 95% for turbidity and 45~83% for $COD_{Cr}$, but rejection rates of total dissolved solid (TDS) were lower than 10%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.2
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• pp.79-86
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• 2017

In this study, the flow and heat transfer characteristics of the finned annular passage were investigated numerically. The annular passage simulates co-axial geothermal heat exchanger, and fins are installed on its inner wall to reduce heat loss from the production passage (annulus) to injection passage (inner pipe). A commercial CFD program, Ansys Fluent, was used with SST $k-{\omega}$ turbulence model. The effects of the geometric parameters of the fin on the inner tube were analyzed under the periodic boundary condition. The result indicated that most parameters had a tendency to increase with an increase in the height and angle of the fin. However, it was confirmed that the Nusselt number of the inner tube on the coaxial 15, 5, 0.3 was lower than that of the smooth tube. Additionally, the Nusselt number of the inner tube exhibited a tendency of decreasing with a decrease in the spacing in Coaxial 15, $S_f$, 0.3.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.533-542
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• 2016

The periodic maintenance of bridges is necessary once they have been constructed and its cost depends on various factors, such as their condition, environmental conditions and so on. To make a decision support system, it is essential to establish a basic reconstruction cost model. In this study, a regression model is suggested for calculating the reconstruction cost for typical cases and influential factors, depending on the type of bridge and its components, by analyzing the basic bridge specifications based on the data of the Bridge Management System (BMS). The details for each case were estimated in consideration of the cost calculation variables. The details for each case were estimated in consideration of the cost calculation variables. The cost model for the new construction of the superstructure, substructure and foundation and the temporary bridge construction and demolition costs were drawn from the regression analysis of the estimation results of typical cases according to the cost calculation variables. The reconstruction costs for different types of bridge were obtained using the cost model and compared with those in the literature. The cost model developed herein is expected to be utilized effectively in maintenance decision making.

• Journal of Soil and Groundwater Environment
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• v.14 no.4
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• pp.15-22
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• 2009

The remediation efficiency for a large scale petroleum-contaminated site was evaluated by using the Engineered Land-farming system which was consists of the following parameters; moisture & nutrient injector data, blower system, HDPE sheet and sump system. To enhance the degradation ability in the early stage, main nutrients such as nitrogen (N) and phosphorus (P) were adjusted for the site condition. As a result of the periodic tilling process, the concentration of contaminated soil was decreased to 348 mg/kg, which was lower than 500 mg/kg (regal standards) while satisfying remediation Efficiency of 82% (the maximum concentration of 1,893 mg/kg). The appropriate temperature range for an active operation was investigated between $28.9{\sim}35.6^{\circ}C$. For the contaminated soils having different initial concentration, the TPH (Total Petroleum Hydrocarbons) concentration was decreased evenly along with the CFU (Colony Forming Unit), moisture content and contaminant concentration after 38days of gratifying the legal standards of under 500 mg/kg.

• Journal of Korea Water Resources Association
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• v.54 no.spc1
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• pp.1083-1093
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• 2021

It is an essential to predict water usage for establishing an optimal supply operation plan and reducing power consumption. However, the water usage by consumer has a non-linear characteristics due to various factors such as user type, usage pattern, and weather condition. Therefore, in order to predict the water consumption, we proposed the methodology linking various techniques that can consider non-linear characteristics of water use and we called it as KWD framework. Say, K-means (K) cluster analysis was performed to classify similar patterns according to usage of each individual consumer; then Wavelet (W) transform was applied to derive main periodic pattern of the usage by removing noise components; also, Deep (D) learning algorithm was used for trying to do learning of non-linear characteristics of water usage. The performance of a proposed framework or model was analyzed by comparing with the ARMA model, which is a linear time series model. As a result, the proposed model showed the correlation of 92% and ARMA model showed about 39%. Therefore, we had known that the performance of the proposed model was better than a linear time series model and KWD framework could be used for other nonlinear time series which has similar pattern with water usage. Therefore, if the KWD framework is used, it will be possible to accurately predict water usage and establish an optimal supply plan every the various event.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.1
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• pp.9-15
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• 2019

Here, we present a facile route to fabricate a vertically stacked 3D porous structure-based triboelectric nanogenerator (TENG) that can be used to harvest energy from the friction in a repetitive contact-separation mode. The unit component of TENG consists of thin Al foil electrodes integrated with microstructured 3D foams such as Ni, Cu, and polyurethane (PU), which provide advantageous tribo-surfaces specifically to increase the friction area to the elastomeric counter contact surfaces (i.e., polydimethylsiloxane, PDMS). The periodic contact/separation-induced triboelectric power generation from a single unit of the 3D porous structure-based TENG was up to $0.74mW/m^2$ under a mild condition. To demonstrate the potential applications of our approach, we applied our TENGs to small-scale devices, operating 48 LEDs and capacitors. We envision that this energy harvesting technology can be expanded to the applications of sustainably operating portable electronic devices in a simple and cost-effective manner by effectively harvesting wasted energy resources from the environment.