• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.597-600
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• 2006

When the energy of the nanoseconds high voltage pulse with hundreds picoseconds of the pulse rise time is emitted into the free space via an antenna, an ultra wide band electromagnetic wave is generated. This electromagnetic wave is expected to be used in transmitting vast amount of informations to far distance, high performance radars, post-packaging pasteurization of food, the detection of underground buried objects, searching of underground water veins or caves, the treatment of waste water or polluted gases and so forth. Additionally, this technology can be used in EMI(electromagnetic interference) evaluation of measuring instruments or printed circuit boards.

• Journal of the Korean Society of Radiology
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• v.6 no.3
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• pp.207-215
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• 2012

As one of photo dynamic therapies, the existing LED photo irradiation method with 635 nm continuous wave has most frequently been used for acne treatment, it suffered from a low energy efficiency and generation of a large amount of heat in tissues requiring improvement measures. In this thesis, a LED photo irradiation system for acne treatment has been designed using PWM(Pulse Width Modulation) mode to enhance the energy efficiency and prevent thermal destruction in tissues. System configuration consisting largely of timer module, PWM module, and photo transfer device has been designed with the use of 1 W LED at a wavelength of 660 nm for the photo transfer device to increase skin penetration depth for treatment of acne. Frequency and wave form generated by using PWM control was verified along with confirmation of output energy of 660 nm LED and surface temperatures of tissues, followed by evaluation of stable energy outputs and stability of tissues. The results indicated that whereas power loss was high and thermal destruction in tissues was exhibited when C.W mode was used to obtain the optical energy of 1 W LED at a wavelength of 660 nm for acne treatment, realization of PWM mode allowed lowering of power consumption for LED through pulse width modulation, and no occurrence of thermal destruction in tissues, suggesting that PWM mode is safer and more effective for treatment of acne than C.W mode.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.322-329
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• 2005

Viscous flows behind transom stern are analyzed based on CFD simulation results. Stern wave pattern is often complicated due to the abrupt change of stern surface curvature and flow separation at transom. When a ship advances at high speed, whole transom stern is exposed out of water, resulting in the so-called 'dry transom'. However, in the moderate speed regime, stern wave development in conjunction of flow separation makes unstable wavy surface partially covering transom surface, i.e., the so-called 'wetted transom'. Transom wave formation is usually affecting the resistance characteristics of a ship, since the pressure contribution on transom surface as well as the wave-making resistance is changed. Flow modeling for 'wetted transom' is difficult, while the 'dry transom modeling' is often applied for the high-speed vessels. In the present study CFD results from the RANS equation solver using a finite volume method with level-set treatment are utilized to assess the topology of transom flow pattern for a destroyer model (DTMB5415) and a container ship (KCS). It is found that transom flow patterns are quite different for the two ships, in conformity to the shape of submerged transom. Furthermore, the existence of free surface seems to after the flow topology in case of KCS.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.2
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• pp.33-42
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• 2011

Zinc plays a key role in genetic expression, cell division, and cell growth and is essential for the functions of more than 450 metalloenzyme. There are high concentrations of zinc in pigment epithelium in bullfrog eye. Zinc deficiency causes night blindness and abnormal dark adaptation. The purpose of this study was to identify ERG (electroretinogram) b-wave sensitivity during light and dark adaptation in bullfrog retina after zinc and zinc chelators treatment such as histidine and TSQ (N-(6-methoxy-8-qunolyl)-p-toluenesulfon amide). Especially, we focused whether histidine act as a zinc chelator in the Muller cell. The results of our study are summarized as follows: 1) Both zinc and histidine elevated ERG b-wave amplitude and threshold in Muller cells by accelerating rhodopsin regeneration time and increased a-peak absorbance during light adaptation. 2) TSQ reduced those by prolonging rhodopsin regeneration time and decrement of a-peak absorbance during light adaptation. 3) Zinc shortened rhodopsin regeneration time and prolonged a-peak absorbance. These results suggested that histidine may act as a zinc-mediated transporter in presynaptic Muller cell membrane rather than zinc chelator and acts as a GABA-receptor inhibitor which blocks $Cl^-$ influx to the postsynapse.

• Journal of radiological science and technology
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• v.21 no.1
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• pp.40-45
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• 1998

To determine its usefulness and safety of extracorporeal shock-wave lithotripsy in common bile duct and pancreatic duct stones, we analyzed the results of 13 patients with common bile duct stones and 6 patients with pancreatic duct stones which were removed by endoscopic procedures using the balloon or basket, who was performed the extracorporeal shock-wave lithotripsy using the ultrasonography for stone localization with a spark gap type Lithotriptor(Dernier MPL 9000, Germany). Fragmentation and complete clearance of the common bile duct and pancreatic duct stones were obtained in 19 of 19 patients(100%). Apart from transient attacks of fever in 2 of 13 patients with common bile duct stones(15%) and mild elevation of serum amylase and lipase in 2 of 6 patients with pancreatic duct stones(33%), no other serious side effects were observed. In our experiences, extracorporeal shock-wave lithotripsy is a safe and useful treatment for endoscopically unretrievable common bile duct and pancreatic duct stones.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.517-526
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• 2018

Climate adaptation strategies for water utilities including 16 water treatment plants(WTPs) in Jeju were investigated. Drought, heat wave, and heavy rain were among the most significant climate factors affecting water utilities in Jeju. Heat wave increases water temperature, which in turn increases the concentration of algae, color, and odor materials. Some adaption strategies for the heat wave can be strengthening water monitoring and introducing advanced water treatments. Heavy rain increases raw water turbidity in surface water. The 7 WTPs that take raw water from streams or springs had a maximum turbidity of less than 50 NTU under heavy rain. However, due to concerns of turbidity spike in treated water, some WTPs discontinued intaking raw water when raw water turbidity increased more than 2 NTU. They instead received treated water from other WTPs which took groundwater for water supply. This happens because of the low skills of employees. Thus, there needs to be an increase in operator competency and upgrade of water facilities for the adaption of heavy rain. To improve adaption for the drought, there should be an increase in the capacity of intake facilities of surface water as well as a decrease in water loss. In addition, water consumption per person should be decreased.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.203-210
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• 2021

Difficulties in treating chronic prostatitis cause physical pain and mental problems not only for the treating doctor, but also for the patient. Accordingly, the device of the present research was developed to help patients suffering from prostate symptoms due to the vibration effect of shock wave energy caused by thermal and mechanical interaction of the external shock wave. The purpose of this study is to provide an effective treatment means for prostatitis and BPH(Benign prostatic hyperplasia) by devising an extracorporeal shockwave therapy device that effectively applies the heat and vibration effects of concentrated energy by MCU and spiral coil module.

• The Journal of Internal Korean Medicine
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• v.39 no.3
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• pp.389-404
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• 2018

Objective: The aim of this study was to investigate acupuncture therapy for post-stroke cognitive disorder to suggest the methods of a study about acupuncture therapy. Methods: Several academic databases were used in this study, including National Digital Science Library (NDSL), National Assembly Library of Korea, Korean Traditional Knowledge Portal, Research Information Sharing Service (RISS), Korean studies Information Service System (KISS), Korean Medical Database (KMBASE), Korea Med, Oriental Medicine Advanced Searching Integrated System (OASIS), PubMed, MEDLINE with Full Text, and China National Knowledge Infrastructure (CNKI). Keywords used were "중풍", "뇌졸중", "인지장애", "침", "acupuncture", and "cognitive disorder". Results: Ultimately, 28 papers were investigated. that were mainly published in 2012 and 2016. Of these, More than two-thirds received a score of one or less on the Jadad scale. Acupuncture points such as GV20, GV24, PC6, EX-HN1, SP6, and GV26 were most frequently used. The treatment duration was mostly 30 minutes or less, and the treatment cycle was mostly for four weeks. Dilatational wave was generally used in pulse wave form, and amplitude of electricity was increased until patients were able to endure. G6805 was generally used in electric acupuncture apparatus. According to results of acupuncture treatment, assessments such as the MMSE (Mini Mental State Examination) and the Montreal Cognitive Function Assessment Scale (MoCA) showed statistically significant improvements in 28 studies. Conclusions: Future research is needed to standardize the treatment of acupuncture, and more diversified high quality papers should be published to help clarify the therapeutic effects of acupuncture and the mechanisms of cognitive disorder post-stroke.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.304-313
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• 2010

This study was undertaken to discover the effects and possible mechanisms of the effect of red ginseng extract (RGE) on spontaneous sleep. The effects of a low dose (10 mg/kg) and a high dose (200 mg/kg) of RGE were compared in rats. After recovery from a surgical operation enabling electroencephalograms recordings, rats were administered RGE orally. RGE was administered orally for 1 day or once per day for 5 days in either 10 or 200 mg/kg doses. Polygraphic signs were recorded for 12 h after oral administration of RGE. Both treatment with a large dose (200 mg/kg) of RGE for one day and treatment with either a large or a small dose for 5 days reduced the number of sleep.wake cycles. Daily treatment with RGE (either 10 or 200 mg/kg) for 5 days augmented NREM and total sleep, but reduced wakefulness. Delta wave activity recorded during non-REM (NREM) sleep and REM sleep was increased after one treatment with RGE (either 10 or 200 mg/kg). Delta wave activity during NREM was enhanced after daily treatment with RGE (either 10 or 200 mg/kg) for 5 days. Both alpha and beta subunits of the $\gamma$-aminobutyric acid $(GABA)_A$ receptor were significantly over-expressed in the hypothalamus of the RGE-treated groups. Moreover, the expression of glutamic acid decarboxylase was also increased in the hypothalamus. These results demonstrate that RGE may regulate spontaneous sleep via $GABA_A$ergic systems.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.99-112
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• 2020

A edible mushroom, Hypsizygus marmoreus is commercially cultivated. However, the researches of cultivation and physiological characteristics were not conducted in Korea. In this study, we conducted on artificial cultivation of H. marmoreus and elucidated the effect of light on the mycelial growth and fruit body development using LED light sources with different wavelength; blue (peak wave length 460nm), green(peak wave length 530nm), yellow(peak wave length 590nm), red(peak wave length 630nm), and white as positive control. Mycelial growth of H. marmoreus strains were inhibited about 30~40% in inhibition ratio under the illumination with blue, green, yellow LED light. However, red LED light was not inhibited. Elongation of stipe was effective under the long wave length such as yellow and red light. Abnormal fruit body was produced under the long wavelength and dark. However, development of pileus was effective under the short wavelength such as green and blue light. Also, as a result of cultivation with mixed light for high quality and harvest, many effective numbers and yields of fruiting bodies were obtained in the mixed treatment of blue and white light, and pileus developed well.