• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.518-524
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• 2004

The feasibility of Y(z) curve method of scanning acoustic microscope using high frequency transducer was experimentally studied for assessment of the thermal degradation in Co-based superalloy. Thermal degradation was performed to simulate the microstructural changes in Co-based superalloy arising from long term exposure at high temperature. Longitudinal wave velocity measured by pulse echo method using 10MHz transducer and leaky surface acoustic wave (LSAW) velocity measured by V(z) curve method using 200MHE transducer were measured to investigate the effect on thermal degradation. Ultrasonic velocity decreased as the aging time increased in both ultrasonic waves. Moreover, the low frequency longitudinal wave velocity decreased a little. Otherwise, the high frequency LSAW velocity drastically decreased up to a maximum of 4.7% at the aging time of 4,000hours. A good correlation was found between LSAW and Vickers hardness. Consequently, V(z) curve method of SAM using high frequency transducer could be a potential tool for assessing thermal degradation.

• Journal of Oriental Neuropsychiatry
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• v.12 no.2
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• pp.103-122
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• 2001

The clinical study was carried out the 58 patients with Headache who were treated in Department of Neuropsychiatry, College of Oriental Medicine, Dae Jeon University from 14 October 1999 to 15 October 2001. The results were summarized as follows. 1. The ratio of male and female was 15:43, 40s(36.2%) was frequent, the ratio of Tension headache and Migraine was 43:12, hypernoia and overwork oneself were the most inducing factor. 2. In distribution of the period of the clinical history, Tension headache was comparatively short term within 1 month(62.8%) and Migraine was comparatively long term over 1 year(91.7%), Tension headache was frequent at whole portion(41.3%) and occipital portion(26.1%), Migraine was frequent at temporal portion(76.9%). 3. In pain type, Tension headache has many vandlike discomport type, Migraine has many pulsatile type, neck-stiffness-pain and dizziness were mainly coexited. 4. Toung aspect has many SULDAMHONGTAEBAEKHOO(舌淡紅苔白厚), GINMAEK(緊脈) and HEUNMAEK(弦脈) were frequent in Pulse type, the GAEDAMSUNKIJEETONG(祛淡順氣止痛) prescription drugs were frequent such as GEYNTONGA(肩痛A), GEYNTONGDODAMTANG(?通導淡湯), Tension headache patients were well treated(90.7%). 5. In Tension headache and Migraine, the Curve has many SL except Tension headache‘s 2th SANGHAN(상한), in Regulation RR was frequent at 1th, 2th, 3th, 4th, 7th SANGHAN and RL was frequent at 5th, 6th SANGHAN, the result of Graph, Activity and Reactivity have many low response at the whole. 6. The Curve was within normal limit at whole portion and frequent SL at temporal portion, the whole and temporal portion s Regulation also have many RR at 1th, 2th, 3th, 4th, 7th SANGHAN and RL at 5th, 6th SANGHAN, Activity and Reactivity have many low response at the whole. 7. The occipital and frontal portion‘s Curve have many SL at 1th SANGHAN, the occipital portion’s Regulation has many RR at 1th, 2th, 4th, 7th SANGHAN and RL at 5th, 6th SANGHAN, Activity has many low response at the whole, Reactivity has many low response at 1th, 4th, 5th, 6th SANGHAN and high response 2th, 3th SANGHAN, the frontal portion s Regulation has many RL at 1th, 3th, 5th, 6th, 7th SANGHAN and RR at 4th SANGHAN, Activity and Reactivity also have many low response at the whole except 6th, 7th SANGHAN respectively.

• International Journal of Highway Engineering
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• v.7 no.2 s.24
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• pp.45-55
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• 2005

It is known that the Q/C(Quality Control) in the early age of portland cement concrete(PCC) pavement gives a huge effect on long term pavement performance. Thus, many studies regarding the construction of PCC pavement have focused on how to assure construction quality at the early age stage. Curing is one of the most important factor in Q/C of PCC pavement. Membrane curing that protects the evaporation of moisture by placing an impermeable layer on the slab surface is the most common practice for curing the PCC pavement. In order to improve the membrane curing practice, the rate of curing compound should be optimized. However, the optimum rate of curing compound considering Korean weather and environmental conditions has not been specified in the pavement construction specifications. In this study, a proper application rate was recommended in terms of minimizing evaporation with several full-scale tests where various rates of curing compound have been applied. Four test sites on the expressway were enlisted during the summer of 2002 and 2003. Application rates tested were in the range of $0. The rate of evaporation, the temperature pattern of the slab and the pulse velocity of concrete surface have been monitored at each test construction. The result from this study showed that the rate of current construction was approximately $160ml/m^2$ and that approximately $400ml/m^2$ of curing application was recommended as the proper rate for minimizing the moisture evaporation.

• Journal of Conservation Science
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• v.30 no.4
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• pp.427-438
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• 2014

To measure the depth and extension on the surface cracks of the stone monument, ultrasonic pulse velocity targeted at the Mulgyeseowon Stele in Changnyeong was used in this research. Additionally, to establish a long-term countermeasure of management and conservation for this stele, we have investigated the material properties and damage on it and have conducted a precise diagnosis by a variety of non-destructive techniques. Our research has revealed that stones of the stele are composed mainly of three rock types according to the parts of it, alkali-feldspar granite, gabbro and diorite. The result of the deterioration evaluation has occurred that cracks, which are observed from every direction in the body of the stele, are the significant factors to reduce structural stability. The ultrasonic velocity for an evaluation on the properties of the stele has revealed that the speed was high in the order of body, pedestal and crown. Furthermore, to understand the present condition and occurrences of the cracks which have measured in many different forms on the stele quantitatively, we have estimated from 0.6 to 24.1cm deep of the cracks by To-Tc method using ultrasonic velocity.

• Journal of Haehwa Medicine
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• v.8 no.2
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• pp.245-257
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• 2000

A clinical study was done 40 patients of chronic prostatitis who was treated in Dept. of Internal Medicine, Oriental Medicine Hospital, Taejon University, from 1 Mar. 1999 to 31 Oct. 1999. The results were as follows. 1. In distribution of age, 30's and 40's were 57.5% the most, 20's and 60's were 35.0%, 50's was 7.5%. 2. In distribution of past history, the urethritis(45.0%) was the most. 3. In distribution of ocupation, a white-collar worker was 35.0%, a business man was 22.5%, a public servant was 12.5%, etc. 4. Sitting the mean time of day were distributed 5~7 hours, above 7 hours, 3~5 hours, under 3 hours, etc. 5. The resting interval of a long distance drive were distributed 2 hours(35.0%), 3 hours(32.5%), etc. 6. The habit of enduring ejaculation during sexual intercourse was showed 45.0%. 7. The habit of enduring urination was showed 20.0%. 8. Influency of mental stress was showed 90.0%. 9. Ten cases(25.0%) were showed riding horse or riding bicycle. 10. Four cases(10.0%) were showed wearing tight trousers. 11. The habit of put a wallet his hip pocket was showed 57.5%. 12. The most common symptom was distributed the others symp-tom(66.8%) and the voiding symptom(63.3%) more than pain-neuro-logical symptom(37.5%) and symptom related with sexual function (26.6%). 13. In distribution of palpation, lower abdominal pain, lumbar pain, perineal or parascrotal pain were mostly showed right side. Moreover diagnosis of pulsation was weakly showed chi pulse of right. 14. Duration of disease were distributed above 1 year(82.5%), under 1 year(17.5%). Degree of prostatitis was severe showed adove 1 year. 15. The distribution of WBC count of the prostatic secretion, com-paring with before therapy and after therapy, were showed from 5 cases to 0 case in very many/HPF, from 23 cases to 13 cases in many/HPF, from 12 cases to 13 cases in 10~30/HPF, from 0 case to 13 cases in under 10/HPF. 16. Therapeutic improvement of symptom were distributed pain-neurological symptom(94.8%), the others symptom(90.8%), the void-ing symptom(89.6%) and symptom related with sexual function(67.5%). 17. Differentiation of symptoms and signs were distributed dificiency of spleen-lung vital energy, wetness-heat of lower warmer, dificiency of spleen-kidney yang, dificiency of kidney yin, wetness-phlegm, dificiency of vital energy and blood. The prescriptions were Bojungikgitang(44.6%), Yukmijihwangtang(20.7%), Palmijihwangtang(12.0%), etc.

• Animal cells and systems
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• v.2 no.4
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• pp.483-488
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• 1998

We previously found that a potent gonadotropin-releasing hormone (GnRH) agonist, buserelin, decreases GnRH promoter activity together with GnRH mRNA level, providing evidence for an autoregulatory mechanism operating at the level of GnRH gene transcription in immortalized GT1-1 neuronal cells. To examine whether agonist-induced decrease in GnRH mRNA level requires the continuous presence of buserelin, we performed a pulse-chase experiment of buserelin treatment. Short-term exposure (15 min) of GT1-1 neuronal cells to buserelin ($10{\mu}M$) was able to decrease GnRH mRNA levels when determined 24 h later. When GT1-1 cells were treated with buserelin ( $10{\mu}M$) for 30 min and then incubated for 1, 3, 6, 12, 24, and 48 h after buserelin removal, a significant decrease in GnRH mRNA levels was observed after the 12 h incubation period. These data indicate that inhibitory signaling upon buserelin treatment may occur rapidly, but requires a long time (at least 12 h) to significantly decrease the GnRH mRNA level. To examine the possible involvement of de novo synthesis and/or mRNA stability in buserelin-induced decrease in GnRH gene expression, actinomycin D ($5{\mu}m/ml$), a potent RNA synthesis blocker, was co-treated with buserelin. Actinomycin D alone failed to alter basal GnRH mRNA Revel, but blocked the buserelin-induced decrease in GnRH mRNA level at 12 h of post-treatment. These data suggest that buserelin may exert its inhibitory action by altering the stability of GnRH mRNA. Moreover, a polvsomal RNA separation by sucrose gradient centrifugation demonstrated that buserelin decreased the translational efficiency of the transcribed GnRH mRNA. Taken together, these results clearly indicate that GnRH agonist buserelin acts as an inhibitory signal at multiple levels such as transcription mRNA stability, and translation.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.667-673
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• 2010

The near fault ground motion (NFGM) is characterized by a single long period velocity pulse with large magnitude. NFGMs have been observed in recent strong earthquakes, Northridge (1994), Japan Kobe (1995), Turkey Izmit (1999), China Sichuan (2008), Haiti (2010) etc. These strong earthquakes have caused considerable damage to infrastructures because the epicenter was close to the urban area, called as NFGM. Extensive research for the far field ground motion (FFGM) have been carried out in strong seismic region, but limited research have been done for NFGM in low or moderate seismic regions because of very few records. The purpose of this research is to investigate and analyze the seismic response of reinforced concrete bridge piers subjected to near-fault ground motions. The seismic performance of six RC bridge piers depending on three confinement steel ratios and three superstructure mass was investigated on the shaking table. From these experimental results, it was confirmed that the reduction of seismic performance was observed for test specimens with lower confinement steel ratio or more deck weight. The displacement ductility of RC bridge piers in terms of the stiffness degradation is proposed based on test results the shaking table.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.4
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• pp.290-298
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• 2018

Herein, an S-band internally-matched power amplifier that shows a power capability of 300 W in a Long Term Evolution(LTE) band 7 is designed and fabricated using a CGHV40320D GaN HEMT from Wolfspeed. Based on the nonlinear model, the optimum source and load impedance are extracted from the source-pull and load-pull simulations at the fundamental and harmonic frequencies, and the harmonic impedance tuning circuits are implemented inside a ceramic package. The internally matched power amplifier, which is fabricated using a thin-film substrate with a high relative permittivity of 40 and an RF35TC PCB substrate, is measured at the pulsed condition with a pulse period of 1 ms and a duty cycle of 10%. The measured results show a maximum output power of 257~323 W, a drain efficiency of 64~71%, and a power gain of 11.5~14.0 dB at 2.62~2.69 GHz. The LTE-based measurement shows a drain efficiency of 42~49% and an ACLR of less than -30 dBc(excluding 2.62 GHz) at an average power of 79 W.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.56-62
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• 2006

Currently, Most of the Backhual and Submarine's networks are being installed using DWDM and EDFA to deal with dramatically increasing internet traffic. In a conventional type optical system, the so-called 3R repeater, fiber non- linearity was not significant factor but it is one of the most important consideration when designing new DWDM network based on the EDFAs. To minimize the signal pulse distortion in long-haul optical network, Zero-dispersion fiber is indispensable but causes the fiber non-linearity. Therefore this conflicting problems should be managed to transmit a high-speed capacity traffic. In this paper, key technologies in DWDM submarine optic network were found out for a high capacity traffic and introduced the dispersion management way for solving the conflicting problems between Zero-dispersion and non-linearity. Lastly designed a dispersion map in section between Korea and Hong-kong.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8947-8950
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• 2014

Immunological functions of heat shock proteins (HSPs) have long been recognized. In this study we aimed to efficiently purify HSP70 from renal cell carcinoma and test it as a tumor antigen for pulsing dendritic cells in vitro. HSP70 was purified from renal cell carcinoma specimens by serial column chromatography on Con A-sepharose, PD-10, ADP-agarose and DEAE-cellulose, and finally subjected to fast protein liquid chromatography (FPLC). Dendritic cells derived from the adherent fraction of peripheral blood mononuclear cells were cultured in the presence of IL-4 and GM-CSF and exposed to tumor HSP70. After 24 hours, dendritic cells were phenotypically characterized by flow cytometry. T cells obtained from the non-adherent fraction of peripheral blood mononuclear cells were then co-cultured with HSP70-pulsed dendritic cells and after 3 days T cell cytotoxicity towards primary cultured renal cell carcinoma cells was examined by Cell Counting Kit-8 assay. Dendritic cells pulsed in vitro with tumor-derived HSP70 expressed higher levels of CD83, CD80, CD86 and HLA-DR maturation markers than those pulsed with tumor cell lysate and comparable to that of dendritic cells pulsed with tumor cell lysate plus TNF-${\alpha}$. Concomitantly, cytotoxic T-lymphocytes induced by HSP70-pulsed dendritic cells presented the highest cytotoxic activity. There were no significant differences when using homologous or autologous HSP70 as the tumor antigen. HSP70 can be efficiently purified by chromatography and induces in vitro dendritic cell maturation in the absence of TNF-${\alpha}$. Conspecific HSP70 may effectively be used as a tumor antigen to pulse dendritic cells in vitro.