• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.12
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• pp.933-940
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• 2017

A wireless power transfer system with a negative impedance converter(NIC) was designed and tested. The system was investigated to identify the effects of ferrites and conductors. To improve the power transfer efficiency(PTE), the Q-factor of the transmitter was enhanced by the negative resistance generated by the NIC. The NIC was composed of an Op-Amp and resistors. The negative resistance was obtained with respect to a resistor connected in a feedback loop. The dimension of the Tx coil was $250mm{\times}250mm{\times}0.8mm$. The impedance and Q-factor were $31+j1874{\Omega}$ and 60, respectively. The negative resistance was selected to be $30{\Omega}$, and the Q-factor was increased to 900 by reduction of the transmitter resistance, which was about 15 times higher than that of a conventional transmitter. The measured PTE was greatly improved in comparison to that of a conventional system. These results demonstrate that the PTE is enhanced by using the NIC.

• Culinary science and hospitality research
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• v.16 no.5
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• pp.247-263
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• 2010

This study was conducted to examine the physicochemical and sensory characteristics of Bulgogi seasoning sauce added with Angelica gigas Nakai extract and salted liquid of Prunus mume. Increasing the amount of salted liquid of Prunus mume in the Bulgogi sauce added with Angelica gigas Nakai extract made its pH and brix decreased. And the lightness(L) value of the samples ranged from 22.50 to 23.43, and the redness(a) and yellowness(b) increased. For the textural characteristics of Bulgogi meat, the addition of salted liquid of Prunus mume decreased its hardness. In the sensory evaluation, Bulgogi added with 10% of salted liquid of Prunus mume made excellent scores in texture, taste and overall preference. Therefore, this results suggest that 10% of salted liquid of Prunus mume and Angelica gigas Nakai extract should be applied to Bulgogi sauce in order to satisfy its preference and functionality. For the changes of total viable cells of Bulgogi seasoning sauce by the storage period, increased amount of salted liquid of Prunus mume showed their number lower than that of the control.

• Tuberculosis and Respiratory Diseases
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• v.55 no.2
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• pp.165-174
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• 2003

Background : Asthma is one of the most prevalent diseases in Korea. Although the guidelines of asthma management were reported in Korea, the present pattern of asthma management by primary physicians has not been studied. The purpose of this study is to elucidate the pattern of asthma management by primary physicians. Methods : In November 2002, 710 primary physicians specializing in internal medicine in Seoul, Korea were provided with two scenarios of asthmatic patients, one mild and the other severe. By mail or interview, the physicians were asked several questions about their present pattern of asthma management for the patients in each scenario. Results : Among 710 primary physicians, we obtained the answers from 325 physicians (response rate 46%). The most preferred prescription was oral theophylline. 71% and 81% of the physicians answered that they would prescribe oral theophylline for the mild and severe asthmatics, respectively. The next prescription preferred were mucolytics and oral ${\beta}_2$-agonist, in that order. However, 36% and 56% of the physicians answered that they would prescribe inhaled steroids for the mild and severe asthmatics, respectively. Among diagnostic tests, physicians preferred pulmonary function test to the rank next to chest radiography. Conclusion : The primary physicians in Seoul prefer oral bronchodilators to inhaled steroids in asthma management. More efforts should be made to reduce the difference between the present pattern of asthma management by primary physicians and the asthma guidelines.

• Tuberculosis and Respiratory Diseases
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• v.78 no.3
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• pp.218-226
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• 2015

Background: Eph receptors and ephrin ligands have several functions including angiogenesis, cell migration, axon guidance, fluid homeostasis, oncogenesis, inflammation and injury repair. The EphA2 receptor potentially mediates the regulation of vascular permeability and inflammation in response to lung injury. Methods: Mice were divided into 3 experimental groups to study the role of EphA2 signaling in the lipopolysaccharide (LPS)-induced lung injury model i.e., IgG+phosphate-buffered saline (PBS) group (IgG instillation before PBS exposure), IgG+LPS group (IgG instillation before LPS exposure) and EphA2 monoclonal antibody (mAb)+LPS group (EphA2 mAb pretreatment before LPS exposure). Results: EphA2 and ephrinA1 were upregulated in LPS-induced lung injury. The lung injury score of the EphA2 mAb+LPS group was lower than that of the IgG+LPS group ($4.30{\pm}2.93$ vs. $11.45{\pm}1.20$, respectively; p=0.004). Cell counts (EphA2 mAb+LPS: $11.33{\times}10^4{\pm}8.84{\times}10^4$ vs. IgG+LPS: $208.0{\times}10^4{\pm}122.6{\times}10^4$; p=0.018) and total protein concentrations (EphA2 mAb+LPS: $0.52{\pm}0.41mg/mL$ vs. IgG+LPS: $1.38{\pm}1.08mg/mL$; p=0.192) were decreased in EphA2 mAb+LPS group, as compared to the IgG+LPS group. In addition, EphA2 antagonism reduced the expression of phospho-p85, phosphoinositide 3-kinase $110{\gamma}$, phospho-Akt, nuclear factor ${\kappa}B$, and proinflammatory cytokines. Conclusion: This results of the study indicated a role for EphA2-ephrinA1 signaling in the pathogenesis of LPS-induced lung injury. Furthermore, EphA2 antagonism inhibits the phosphoinositide 3-kinase-Akt pathway and attenuates inflammation.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.802-807
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• 2000

Diffuse pulmonary nodular lesions have many causes. When they are caused by infection, the likely organisms are M. tuberculosis and various fungi. Silicosis, eosinophilic granuloma and pulmonary metastasis should be considered for differential diagnosis. Differential diagnosis needs detailed clinical history, physical examination and various laboratory tests. A case of persistent diffuse pulmonary nodular lesions which had persisted 5 years is reported. The patient was a 25 years old man with minimal pulmonary symptoms. Detailed past history and physical examination suggested thyroid tumor. Chest radiography showed numerous evenly sized well-defined nodules scattered in entire lung fields. Previous chest X-rays showed similar nodular lesions, which had lasted for 5 years. The number of nodules was slightly increased. Neck CT showed heterogenous mass in left lobe of thyroid gland and multiple lymphadenopathies along both internal jugular chains. Total thyroidectomy was performed. A case of lung metastasis which progressed slowly in papillary thyroid cancer is reported.

• Journal of Life Science
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• v.20 no.8
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• pp.1207-1213
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• 2010

The purpose of this study was to evaluate the effect of porcine cancellous bone as a scaffold in a rat calvarial defect model. Critical-sized defects were created in 30 male Sprague-Dawley rats. The animals were divided into critical defect (CD, n=10), $\beta$-tricalcium phosphate (TCP) graft (BT, n=10) and porcine cancellous bone graft (PCB, n=10) groups. Each defect was filled with $\beta$-TCP mixed with fibrin glue or porcine cancellous bone powder mixed with fibrin glue. In the CD group, the defect was left empty. All rats were sacrificed at 8 weeks after bone graft surgery, and bone formation was evaluated by gross observation, plain radiography, micro-computed tomography scanning and histological evaluation. Repair of bone defect was the least in the CD group, and significant new bone formation was observed in the PCB group. Grafting of porcine cancellous bone was more efficient for regenerating new bone than grafting $\beta$-TCP.

• Fire Science and Engineering
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• v.24 no.6
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• pp.61-68
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• 2010

In this paper, a research and development result for the implementation of single station fixed temperature detector for residential fire prevention is described. The detector was developed for the certification in Japanese market because of very low domestic market situation. It is in the situation that there is no other regulation especially for residential detectors in Korea, Japanese case has been reviewed. Investigation of domestic legal circumstances and a comparative study for the test standard owned by KFI (Korea Institute of Fire Industry & Technology) and JFEII (Japan Fire Equipment Inspection Institute) respectively are also indicated. The detector alarms with a buzzer and an indicating LED. In the implementation ultra low power MCU(Micro Controller Unit) is applied to control the sleeping state and the monitoring state properly with low current consumption. To sense the temperature fast response thermistor is adopted in the design of fixed temperature residential detector. Automatic test function and alarm stop function are also considered in the design. The major factors which influence to current consumption are explained for the purpose of design reference. Main electronics circuit parts related to it's characteristics of the detector are described. It is explained that the measured current and experimental result of the battery discharge can be met over 10 years operation.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.289-295
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• 2011

Produce, including leafy vegetables, has been implicated in several outbreaks of food illness. To evaluate microbiological safety of lettuce and it's cultivation area, a total of 147 samples were collected from lettuce farms and post harvest facility at Icheon, Gyeonggi province. The collected samples were assessed for presence of sanitary indicator microorganisms (Aerobic plate count, coliform count, Escherichia coli) and foodborne pathogens (Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus). The population of APC was over 4.0 log CFU from most of the samples. While the numbers of APC, and coliform of lettuce at 62 days after transplanting were 4.18 log CFU/g, and 1.00 log CFU/g, respectively, those of 10 days after transplanting were 5.37 log CFU/g, and 2.87 log CFU/g, respectively. B. cereus was highly detected from soil and balance which were contaminated with 3.5 log CFU/g, and 2.6 log CFU/100 $cm^2$, respectively. The number of E. coli recovered from gloves was 3.5 log CFU/hand. However, E. coli O157:H7, Salmonella spp., and L. monocytogenes were not detected. These data suggested that risk management system should be introduced to lettuce farms to enhance safety of lettuce.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.55-62
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• 2012

EZW, also known as Embedded Zerotree Wavelet, is a technique that allows transforming original images into wavelet, then again compressing images using the transformed data. This algorithm demonstrates a simple structure and remarkable effectiveness. This paper has reformed the EZW to improve a compression efficiency. Fundamentally, EZW evaluates the priority level of wavelet-transformed data and stores them into four different categories considering the priority level of the data as well as their location information. The four categories are represented as the symbols P, N, Z, and T. Here, P and N correspond to the volume of data and the priority level whereas Z and T show the location information of data. Each letter is stored through the process of dominant pass. However, here is when the data of Z and T are stored redundantly which lead to unnecessary increase of data volume. In this paper, we propose a modified version of Embedded Zerotree Wavelet algorithm, which is designed to efficiently reduce the volume of redundantly stored data using four additionally inserted symbols. We name it EEZW, Extended Embedded Zerotree Wavelet. The proposed algorithm demonstrates the efficiency verified by a number of image and confirms an outstanding result through the PSNR(Peak Signal To Noise Rate) values, which measure their quality of images.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.4
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• pp.351-357
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• 2012

To determine whether the seaweed Saccharina japonica can effectively utilize dissolved nutrients from Sebastes schlegeli fish cultures, a laboratory experiment was conducted in a static system for 7 days at ESFRI, NFRDI in Korea. The experiment included an S. schlegeli monoculture system and an S. schlegeli-S. japonica IMTA system. Saccharina schlegeli density ($415{\pm}24g$; mean${\pm}$SE) remained the same in all treatments, whereas seaweed density varied across treatments of 0, 0.5, 1, 2, and 3 kg (control and T1-T4, respectively). During the experiment, nutrient ($NH_4^+$ and $PO_4^{3-}$) concentrations were measured at 24-h intervals. $NH_4^+$ concentration of the control group increased from $0.117{\pm}0.021mg/L$ at the start of experiment to $5.836{\pm}0.904mg/L$ at the end of experiment. $NH_4^+$ concentrations of each treatment were $3.004{\pm}0.040$, $2.086{\pm}0.133$, $1.642{\pm}0.121$ and $0.775{\pm}0.007mg/L$ in T1, T2, T3, and T4, respectively, at the end of experiment. The concentration of $PO_4^{3-}$ exhibited a similar trend to $NH_4^+$ concentration. $NH_4^+$ and $PO_4^{3-}$ concentrations significantly decreased with increased S. japonica thallus density each day (P<0.05). The nutrient removal efficiency (NRE) and nutrient uptake rate (NUR) showed different relationships with changes in thallus density; NRE increased but NUR decreased as thallus density increased. Based on measured concentrations of $NH_4^+$ and S. japonica weight, regression analysis defined the relationship between as an exponential function, $Y=3.8165e^{-0.505X}$ ($R^2$ = 0.9552). Our results demonstrated that S. japonica can function as an efficient component in IMTA with environmental and potentially economic benefits for fish hatcheries.