• Imaging Science in Dentistry
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• v.53 no.3
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• pp.217-220
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• 2023

Purpose: This pilot study was conducted to evaluate half-value layer (HVL) measurements obtained using a semiconductor dosimeter for intraoral radiography. Materials and Methods: This study included 8 aluminum plates, 4 of which were low-purity (less than 99.9%) and 4 high-purity (greater than 99.9%). Intraoral radiography was performed using an intraoral X-ray unit in accordance with the dental protocol at the authors' affiliated hospital: tube voltage, 60 kVp and 70 kVp; tube current, 7 mA; and exposure time, 0.10 s. The accuracy of HVL measurements for intraoral radiography was assessed using a semiconductor dosimeter. A simple regression analysis was performed to compare the aluminum plate thickness and HVL in relation to the tube voltage (60 kVp and 70 kVp) and aluminum purity (low and high). Results: For the low-purity aluminum plates, the HVL at 60 kVp (Y) and 70 kVp (Y) was significantly correlated with the thickness of the aluminum plate (X), with Y=1.708+0.415X (r=0.999, P<0.05) and Y=1.980+0.484X (r=0.999, P<0.05), respectively. Similarly, for the high-purity aluminum plates, the HVL at 60 kVp (Y) and 70 kVp (Y) was significantly correlated with the plate thickness(X), with Y=1.696+0.454X (r=0.999, P<0.05) and Y=1.968+0.515X (r=0.998, P<0.05), respectively. Conclusion: This pilot study examined the relationship between aluminum plate thickness and HVL measurements using a semiconductor dosimeter for intraoral radiography. Semiconductor dosimeters may prove useful in HVL measurement for purposes such as quality assurance in dental X-ray imaging.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2797-2801
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• 2023

CdZnTeSe (CZTS) has attracted attention for applications in X- and gamma-ray detectors owing to its improved properties compared to those of CdZnTe (CZT). In this study, we grew and processed single crystals of CZT and CZTS using the Bridgeman method to confirm the feasibility of using a dosimeter for high-energy X-rays in radiotherapy. We evaluated their linearity and precision using the coefficient of determination (R²) and relative standard deviation (RSD). CZTS showed sufficient RSD values lower than 1.5% of the standard for X-ray dosimetry, whereas CZT's RSD values increased dramatically under some conditions. CZTS exhibited an R² value of 0.9968 at 500 V/cm, whereas CZT has an R² value of 0.9373 under the same conditions. The X-ray response of CZTS maintains its pulse shape at various dose rates, and its properties are improved by adding selenium to the CdTe matrix to lower the defect density and sub-grain boundaries. Thus, we validated that CZTS shows a better response than CZT to high-energy X-rays used for radiotherapy. Further, the applicability of an onboard imager, a high-energy X-ray (>6 MV) image, is presented. The proposed methodology and results can guide future advances in X-ray dose detection.

• Korean Journal of Materials Research
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• v.34 no.7
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• pp.321-329
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• 2024

In this work, a series of BaTiO₃-based ceramic materials, Ba(Al_0.5Nb_0.5)_xTi_1-xO₃ (x = 0, 0.04, 0.06, 0.08), were synthesized using a standard solid-state reaction technique. X-ray diffraction profiles indicated that the Al+Nb co-doping into BaTiO₃ does not change the crystal structure significantly with a doping concentration up to 8 %. The doping ions exist in Al³⁺ and Nb⁵⁺ chemical states, as revealed by X-ray photoelectron spectroscopy. The frequency-dependent complex dielectric properties and electric modulus were studied in the temperature range of 100~380 K. A colossal dielectric permittivity (>1.5 × 10⁴) and low dielectric loss (<0.01) were demonstrated at the optimal dopant concentration x = 0.04. The observed dielectric behavior of Ba(Al_0.5Nb_0.5)_xTi_1-xO₃ ceramics can be attributed to the Universal Dielectric Response. The complex electric modulus spectra indicated the grains exhibited a significant decrease in capacitance and permittivity with increasing co-doping concentration. Our results provide insight into the roles of donor and acceptor co-doping on the properties of BaTiO₃-based ceramics, which is important for dielectric and energy storage applications.

• Journal of Korean Academy of Nursing
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• v.5 no.2
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• pp.74-91
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• 1975

A purpose of this study was to compare the breast massage and manual expression of the breast before engagement after delivery with the time of engagement, the throbbing pain in breast, the first amount of breast milk and involution of the uterus. The subjects selected for this study were 138 women (experimental group;69, control group :69) who were admitted to the Dept. of Obtest. and Gyneco. of Kyung Hee University Hospital from Jan. 5 to June 5, 1975. The results of study were as follows; 1 The average age of the women 26.9 years old in the experimental group and 27.6 years old in the control group. As to religion, the number of those who had no religion was 58.0 percent and 62.4 percent respectively. Classified according to occupation, there were 87.0 percent in house wives of the booths group. Educational background; 87.0 percent of high school graduates or above, 78.3 percent respectively. The occupation of husband 53.7 percent of company employees stood highest and 42.0 percent respectively. In according to the grade of wards, 55.1 percent and 52.2 percent of four-men room stood highest. 2. Physical condition: Body weight before this Pregnancy(T=0.4962, N.S.), the size of breast(X²df2 = 0.1728, N.S.), the shape of nipple(X²df3 =1.3804, N.S.), hemoglobin's level of the first day after delivery(T=1.2572, N.S.), the above were showed non significant between the experimental group and control group The investigator found any difference between the two groups of the health condition during the pregnancy, 3. The rate of no experience of breast massage during pregnancy was 85 percent and 75.4 percent (X²df1=2.2562, N.S.). 4. As to the meal during hospitalization after delivery: The booth of the groups in ordinary food took usually of meyer soup and milk(X²df8=2.5957, N.S.). 5. The relation between the first step of breast massage, second step of the manual expression of breast before engagement after delivery and time of engagement : average time of engagement in the experimental group (2.1 days±0.8) was shortened than the control group (3.3 days±1.2). (T=-6.9045, P< 0.005). It toot less time in the experimental group of primipara(2.2days±0.7) than in the control group (3.1day±1.2) and it also took less time in the experimental group of multipara (2.0 days±0.9) than in the control group (3.5days±1.4). (Primipara T=-3.9266, 0< 0.005. Multipara T= 5.2356, P<0.005). 6. The relationship between the first step of the massage and second step of manual expression and the throbbing pain at the time of engagement: The experimental group showed less effect than control group (X²df4= 27.3342 P<0.005). The separate study of primipara and multipara showed remarkable difference in the group of primipara)X²df4=20.7285, p<0.005) and little difference in the multipara group (X²df4=8.8351, p< 0. 10). 7. The relationship between the first step of the breast massage, second stop of the manual expression and first amount of breast milk: The average amount of breast milk increased more conspicuously in the experimental group (33.8㎖±23.4) than in the control(29.8㎖±25.3) (T=0.8262, N.S.). No remarkable difference was found in the respective groups that investigated in the groups of primipara and of multipara. (Primipara T=1.1467, N.S., Multipara T=-0.0354, N.S.). 8. The relationship between the first step of breast massage and second step of manual expression of breast and involution of uterus : Average time needed for uttering involution was sooner in the experimental group of primipasa(-3.3 F.B.±1.1), than the control group of primipara (-2.5F. B.±1.2), and it was sooner in the experimental group of muitipara (-3.0 F. B.±l..3), than the control group of multipara(-2.3 F.B±0.9). Primipara T=-2.9272, p< 0.005, Multipara T=2.5557, p< 0.01).

• Radiation Oncology Journal
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• v.3 no.2
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• pp.163-168
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• 1985

Intraocular melanoma is the most common primary occular malignancy in adult above the age of 20. Before treatment of intraocular melanoma, it is essential to do complete work-ups including LFT (LDH, SGPT), chest X-ray, whole body bone scan. Also, liver-spleen and brain scan will be done if clinically indicated. Though, malignant melanoma is radioresistant, however, show rapid tumor shrinkage after irradiation with total tumor dose of 7,000 to 8,000 rads in 7-8 weeks.

• Korean Journal of Animal Reproduction
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• v.8 no.2
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• pp.110-115
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• 1984

These experiments were carried out to obtain the information about the optimal pH osmolality affecting in vitro fertilization of the mouse eggs, to elucidate the 2-cell block to development in vitro and to find out the method of controlling the subsequent embryo development in vitro. pH and osomlality was adjusted by adding NaCl or NaHCO3 to the basic salt solution. In vitro fertilization were carried out by inroducting the cumulus masses to the suspension of epididymal spermatozoa at each pH, osmolality, and 10${\mu}$M-EDTA medium. The results obtained in these experiments were summarized as follows: 1. The fertilization rates in vitro at each medium of 235, 252, 269, 286, 306, 323, 345, 368, 393 mosmol were 15.6, 38.2, 65.7, 75.6, 80.9, 74.3, 58.1, 35.1, 24.3, 11.1%, respectively. 2. The fertilization rates in vitro at each medium of pH 6.1, 6.4, 6.7, 7.0, 7.3, 7.6, 7.9, 8.1 were 11.8, 17.9, 32.4, 61.9, 79.5, 76.7, 53.5, 13.6%, respectively. 3. In case of ICR female x ICR male embryos, the development rate of 2-cell embryos to 4-8 cell embryos was 16.2% at normal medium, but the rate was increased to 49.3% in medium containging 10 ${\mu}$M-DETA; In case of C3H female x ICR male embryos, the development rate was 41.0% at normal medium, but the rate was increased to 71.7% at 10 ${\mu}$M-EDTA-medium.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.172-176
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• 2020

The implementation of a low phase noise voltage controlled oscillator (VCO) is important for the signal integrity of wireless communication terminal. A low phase noise wideband VCO for a wireless local area network (WLAN) application is presented in this paper. A 6-bit coarse tune capacitor bank (capbank) and a fine tune varactor are used in the VCO to cover the target band. The simulated oscillation frequency tuning range is from 8.6 to 11.6 GHz. The proposed VCO is desgned using 65 nm CMOS technology with a high quality (Q) factor bondwire inductor. The VCO is biased with 1.8 V VDD and shows 9.7 mA current consumption. The VCO exhibits a phase noise of -122.77 and -111.14 dBc/Hz at 1 MHz offset from 8.6 and 11.6 GHz carrier frequency, respectively. The calculated figure of merit(FOM) is -189 dBC/Hz at 1 MHz offset from 8.6 GHz carrier. The simulated results show that the proposed VCO performance satisfies the required specification of WLAN standard.

• Journal of Korean Traditional Oncology
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• v.10 no.1
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• pp.87-91
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• 2005

Objective: It is the aim of the present paper to derive further studies evaluating the effectiveness of oriental medical treatment on SCLC patients. We present a case of SCLC patient who survives over 8 years. Method: We followed all of treatments and examination. We prescribed to the patient what to take HangAmDan (HAD) three times a day. Chest X-ray was performed to evaluate the therapeutic efficacy. Results and conclusion: The patient survives over 8 years. Chest X-rays were shown partial regression. Conclusion: This case may give us a possibility of that oriental medical treatment offers potential benefits for patients with SCLC.

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.388-393
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• 2000

Localized fibrous tumor of the pleura is very rare. Most of them are benign, but some are malignant. This clause does not relate with the rest of the sentence. The single best predictor of clinical benignity is whether the tumor can be totally resected. We experienced a case of localized fibrous tumor of the pleura in a 57 year old man with right chest pain and cough. He was informed of a $8{\times}5cm$ mass in his right lower lung field, which was benign 3 years ago. Preoperative chest x-ray showed an increased hazy density at right lower lung field, and CT scan showed a $12{\times}8cm$ huge mass, which was located in right lower thorax. Left thoracotomy was done to excise a $12{\times}8{\times}5cm$(1200gm) sized large mass delete. The patient was discharged without any complications postoperatively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.6
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• pp.574-581
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• 2002

Microstrip $8{ imes}2$ sub-array antennas for a extension to active phased array antennas are designed, fabricated and measured for TX/RX dual operation in satellite communication and a reception of satellite broadcasting. For the frequency range from 11.7 to 12.75 GHz for RX and from 14 to 14.5 GHz for TX, two orthogonal linear polarizations of ${pm}45^{\circ}$ are used to transmit and receive simultaneously with one radiator. They adopt dual resonance between two patches for wideband characteristics in RX band and show isolation characteristics over 20 dB. An electrical beam tilt of $30^{\circ}$ is achieved and a tapered power distribution, narrow element spacing are used for the purpose of low side-lobe characteristics.