• Title/Summary/Keyword: material homogeneity

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Archaeometric Implication and Material Characteristics for Bricks and Roof Tiles from the Bogd Khaan Palace and Choijin Lama Temple in Ulaanbaatar, Mongolia (몽골 울란바토르 복드칸 궁전 및 초이진 라마사원 벽돌과 기와의 재료학적 특성 및 고고과학적 의미)

  • Suh Batbaatar;Hyukju Yang;Chan Hee Lee
    • Economic and Environmental Geology
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    • v.57 no.5
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    • pp.647-664
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    • 2024
  • Material and archaeometric characteristics of the original and repaired bricks and roof tiles of the Bogd Khaan Palace and the Choijin Lama Temple, which represent modern Mongolian architecture, were analyzed. These bricks and roof tiles are light gray, and the repaired ones mostly had higher specific gravity and porosity than the original ones. In the body clay, coarse grained sub-angular quartz, alkali feldspar, plagioclase and mica are commonly observed, and hornblende was partially detected. Compared to the original bricks and roof tiles, the repaired ones have a homogeneous substrate and significantly less tempers, suggesting that refined techniques were applied. Weight loss of these bricks and roof tiles was lower in the repaired ones than the original ones, and although there were thermal deformation and non recrystallized. Also, Al2O3 was high in the original bricks and roof tiles, and CaO was high in the repaired ones, and Na2O and ignition loss were low. However, since the other elements showed almost the same behavioral characteristics, it is interpreted that they used homogeneous body clay regardless of location and time. Therefore, the clay content of the raw materials for the original bricks and roof tiles were higher than that used for the repair, but it is highly likely that they were procured from almost the same soil as the body clay, and the firing environment does not seem to have affected the geochemical behavior of the body clay. But, the high Al2O3 and CaO in the repaired bricks and roof tiles indicates the possibility of partial refinement and mixing of the clay. There were no high-temperature minerals in all the bricks and roof tiles, and based on the detection of mica and hornblende, the absence of clay minerals and the thermal deformations of the substrate, their firing temperature is presumed to be 850 to 900℃. This was almost the same in the bricks and roof tiles used for the repairs. This result is significant as material science data for the bricks and roof tiles used in modern Mongolian architecture, and will be useful grounds for examining the making techniques of bricks and roof tiles for future restorations.

A Study on Usefulness of Clinical Application of Metal Artifact Reduction Algorithm in Radiotherapy (방사선치료 시 Metal artifact reduction Algorithm의 임상적용 유용성평가)

  • Park, Ja Ram;Kim, Min Su;Kim, Jeong Mi;Chung, Hyeon Suk;Lee, Chung Hwan;Back, Geum Mun
    • The Journal of Korean Society for Radiation Therapy
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    • v.29 no.2
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    • pp.9-17
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    • 2017
  • Purpose: The tissue description and electron density indicated by the Computed Tomography(CT) number (also known as Hounsfield Unit) in radiotherapy are important in ensuring the accuracy of CT-based computerized radiotherapy planning. The internal metal implants, however, not only reduce the accuracy of CT number but also introduce uncertainty into tissue description, leading to development of many clinical algorithms for reducing metal artifacts. The purpose of this study was, therefore, to investigate the accuracy and the clinical applicability by analyzing date from SMART MAR (GE) used in our institution. Methode: and material: For assessment of images, the original images were obtained after forming ROIs with identical volumes by using CIRS ED phantom and inserting rods of six tissues and then non-SMART MAR and SMART MAR images were obtained and compared in terms of CT number and SD value. For determination of the difference in dose by the changes in CT number due to metal artifacts, the original images were obtained by forming PTV at two sites of CIRS ED phantom CT images with Computerized Treatment Planning (CTP system), the identical treatment plans were established for non-SMART MAR and SMART MAR images by obtaining unilateral and bilateral titanium insertion images, and mean doses, Homogeneity Index(HI), and Conformity Index(CI) for both PTVs were compared. The absorbed doses at both sites were measured by calculating the dose conversion constant (cCy/nC) from ylinder acrylic phantom, 0.125cc ionchamber, and electrometer and obtaining non-SMART MAR and SMART MAR images from images resulting from insertions of unilateral and bilateral titanium rods, and compared with point doses from CTP. Result: The results of image assessment showed that the CT number of SMART MAR images compared to those of non-SMART MAR images were more close to those of original images, and the SD decreased more in SMART compared to non-SMART ones. The results of dose determinations showed that the mean doses, HI and CI of non-SMART MAR images compared to those of SMART MAR images were more close to those of original images, however the differences did not reach statistical significance. The results of absorbed dose measurement showed that the difference between actual absorbed dose and point dose on CTP in absorbed dose were 2.69 and 3.63 % in non-SMRT MAR images, however decreased to 0.56 and 0.68 %, respectively in SMART MAR images. Conclusion: The application of SMART MAR in CT images from patients with metal implants improved quality of images, being demonstrated by improvement in accuracy of CT number and decrease in SD, therefore it is considered that this method is useful in dose calculation and forming contour between tumor and normal tissues.

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Effect of Sex Education on Middle School Students' Access to the Obscene Online Computer and Video Film Contents (성교육이 중학생의 컴퓨터와 비디오 음란물 접촉에 미치는 효과)

  • Woo, Hae-Ja;Kim, Chung-Nam;Park, Kyung-Min
    • Research in Community and Public Health Nursing
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    • v.12 no.3
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    • pp.795-814
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    • 2001
  • To evaluate the effect of sex education on middle school students' access to the obscene online computer and video film contents. 154 students were selected as experimental group. and 154 students were selected as control group, sampled randomly from Andong. Kyungbook, Korea. An analysis was performed. A non-equivalent control group pre test-post test research design was used. The data were collected from April 2nd to April 19th. 2001. A pre-survey was done on general characteristics and the condition of accessing obscene online computer and video film contents on both experimental and control group. From the survey results information. sex education contents were put together. The researcher organized 3 ready-made sex education program and explained to the four school health nurses about the ready-made sex education program step by step and they educated their selected students with three classes of 45 minutes lecture. Two weeks after the last lecture, a post-test was conducted. Four weeks from the last lecture, another post-test was conducted. The existing studies by Choi Yongseon(1998) and Kim Hyeok(1998) were reviewed and two professors in the department of community health nursing advised on the study questionnaire writing. An SPSS Win 10.0 was used. The data of respondents' general characteristics were analyzed using frequency and percentage. $X^2$ test was used to verify the homogeneity of the experimental group and the control group. Repeated Measures ANOVA was used to find out whether sex education had an effect on the awareness of obscene online computer and video film contents and under-age prostitution through the online computer networks. and time and frequency of access to the obscene online computer and video film contents. The results of the study are as follow. 1. The results of the verification of homogeneity between the experimental group and the control group showed that there was no significant difference between the experimental group and the control group. 2. The first hypothesis, 'the experimental group which received sex education would have a higher level of awareness of accessing obscene contents than the control group which did not receive the education' was supported at p<0.0001. 3. The second hypothesis. 'the experimental group which received sex education would have a higher level of awareness of underage prostitution on computer networks than the control group which did not receive the education' was supported at p<0.05. 4. The third hypothesis, 'the experimental group which received sex education would spend time less accessing obscene video and computer contents than the control group which did not receive the education' was rejected at p>.05. 5. The 4-1 hypothesis. 'the experimental group which received sex education would access obscene computer contents less frequently than the control group which did not receive the education' was supported at p<0.0001. 6. The 4-2 hypothesis, 'the experimental group which received sex education would access obscene video contents less frequently than the control group which did not receive the education' was supported at p<0.0001. In conclusion, a systematic step-by-step sex education program should be developed to protect middle school students from the harmful online computer and video film access. An effective teaching material for sex education should be prepared to decrease middle school students' access to obscene online computer and video film contents.

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Comparison and Evaluation of radiotherapy plans by multi leaf collimator types of Linear accelerator (선형가속기의 다엽콜리메이터 형태에 따른 치료계획 비교 평가)

  • Lim, Ji Hye;Chang, Nam Joon;Seok, Jin Yong;Jung, Yun Ju;Won, Hui Su;Jung, Hae Youn;Choi, Byeong Don
    • The Journal of Korean Society for Radiation Therapy
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    • v.30 no.1_2
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    • pp.129-138
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    • 2018
  • Purpose : An aim of this study was to compare the effect of multi leaf collimator(MLC) types for high dimension radiotherapy in treatment sites used clinically. Material and Method : 70 patients with lung cancer, spine cancer, prostate cancer, whole pelvis, head and neck, breast cancer were included in this study. High definition(HD) MLC of TrueBeam STx (Varian Medical system, Palo Alto, CA) and millenium(M) MLC of VitalBeam (Varian Medical system, Palo Alto, CA) were used. Radiotherapy plans were performed for each patient under same treatment goals with Eclipse (Version 13.7, Varian Palo Alto USA, CA). To compare the indicators of the radiotherapy plans, planning target volume(PTV) coverage, conformity index(CI), homogeneity index(HI), and clinical indicators for each treatment sites in normal tissues were evaluated. To evaluate low dose distribution, $V_{30%}$ values were compared according to MLC types. Additionally, length and volume of targets for each treatment sites were investigated. Result : In stereotatictic body radiotherapy(SBRT) plan for lung, the average value of PTV coverage was reduced by 0.52 % with HD MLC. With SBRT plan using HD MLC for spine, the average value of PTV coverage decreased by 0.63 % and maximum dose decreased by 1.13 %. In the test of CI and HI, the values in SBRT plan with HD MLC for spine were 1.144, 1.079 and the values using M MLC were 1.160, 1.092 in SBRT plan for lung, The dose evaluation of critical organ was reduced by 1.48 % in the ipsilateral lung mean dose with HD MLC. In prostate cancer volumetric modulated arc therapy(VMAT) with HD MLC, the mean dose and the $V_{30}$ of bladder and the mean dose and the $V_{25}$ of rectum were reduced by 0.53 %, 1.42 %, 0.97 %, and 0.69 %, respectively (p<0.05). The average value of heart mean dose was reduced by 0.83 % in breast cancer VMAT with M MLC. Other assessment indices for treatment sites showed no significant difference between treatment plans with two types of MLC. Conclusion : Using HD MLC had a positive impact on the PTV coverage and normal tissue sparing in usually short or small targets such as lung and spine SBRT and prostate VMAT. But, there was no significant difference in targets with long and large such as lung, head and neck, and whole pelvis for VMAT.

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A Review on Principles and Access Methods to Sasang Constitutional Medicine of Music Therapy (음악치료(音樂治療)의 원리(原理)와 체질의학적(體質醫學的) 접근을 위한 검토)

  • Lee, Ji-Young;Park, Seong-Sik
    • Journal of Sasang Constitutional Medicine
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    • v.18 no.1
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    • pp.30-40
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    • 2006
  • 1. Objectives The present study purposed to examine the contents and the principles of music therapy according to Oriental medicine theories in order to prove that music therapy is not a new research area but its principle is found in the long tradition of Oriental medicine. 2. Methods We investigate the possibility of music therapy based on Oriental medicine theories and examine the meanings of music therapy from the viewpoint of Oriental medicine. 3. Conclusions and discussions (1) The principles of music therapy are the principle of homogeneity, catharsis and balance. (2) When one’s mind changes, there are naturally occurred sounds, which are called Oseong (五聲: the oriental five voices exhalation, laughing, singing, wailing and groaning), and the notes defined by arranging the Oseong according to the principle of Ohaeng (五行: the oriental five phases wood, fire, earth, metal, water) are Oheum (五音: the oriental five musical notes Gakeum, Chieum, Gungeum, Sangeum and Wooeum.). If Eum (musical notes) is classified into Ohaeng, it can be divided into Gakeum, Chieum, Gungeum, Sangeum and Wooeum. (3) Change of Sinji (神志: consciousness) induces change of Gigi (氣機: function of Gi), which can change the character of voices. Oseong controls the functions of Ojang (五臟: the oriental five viscera) by ruling one’s Jeongji (情志: emotion). It can reduce the damage of the viscera caused by excessive vent of emotion resulted from unconscious expression of Oseong - Hoseong (呼聲: exhalation), Soseong (笑聲: laughing), Gaseong (歌聲: singing), Gokseong (哭聲: wailing) and Sinseong (呻聲: groaning). (4) Yijeongseungjeong (以情勝情: Control emotion with emotion) therapies, which suppresses an emotion by stimulating another, include Noseungsabeop (怒勝思法: Control anxiety with anger), Heeseungbibeop (喜勝悲法: Control sorrow with joyfulness), (思勝恐法: Control fear with anxiety), Biseungnobeop (悲勝愁法: Control anger with sorrow) and Gongseungheebeop (恐勝喜法: Control joyfulness with fear). (5) Seongeum (聲音: voices and musical notes) can be applied to a stimulation method that not only harmonizes the rhythm of living organs but also controls the occurrence of diseases caused by mutual Pyeonseongpyeonsoi (偏盛偏衰: relative preponderance and weakness) through direct induction of the strength and weakness of Gi function of the oriental five viscera in a human body according to the individual character. Sounds preferred by the patient, the material of an instrument selected by the patient, the character of rhythm and music expressed by the patient and the sound or voice uttered frequently by the patient can be considered in diagnosis and treatments for the patient’s body and mind.

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The Differences between Ruptured and Unruptured Mediastinal Teratoma (파열된 종격동 기형종과 단순 기형종과의 차이)

  • Cho, Suk-Ki;Lee, Eung-Bae
    • Journal of Chest Surgery
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    • v.42 no.3
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    • pp.355-360
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    • 2009
  • Background: Benign teratoma is mostly asymptomatic, but this tumor rarely ruptures into the adjacent structure such as the pleural space, pericardium, lung parenchyma or tracheobronchial tree. Thus, it is important to differentiate ruptured teratoma from unruptured teratoma. This study evaluated the difference between ruptured and unruptured benign teratoma. Material and Method: Twenty-four cases of surgically resected benign teratomas were reviewed retrospectively. The clinical symptoms, chest CT findings and operative findings of the ruptured teratoma were compared with those of the unruptured teratoma. Especially, the tumor size, wall thickness, location of the mass, internal septation, homogeneity, calcification and ancillary findings were evaluated on CT. Result: Of the 24 patients, 7 patients were diagnosed with ruptured teratoma. Severe symptoms were more commonly found for ruptured teratoma than for unruptured teratoma. The ruptured teratoma had a tendency to display calcification and such ancillary findings as collapse or consolidation of the lung parenchyma. For the ruptured teratoma, the resection was performed by sternotomy or thoracotomy, and more lung resection was included. Conclusion: Calcification within the mass and changes in the lung parenchyma on the preoperative CT findings can be diagnostic signs of a ruptured teratoma. The demonstration of ruptured teratoma is important not only for making the early diagnosis, but also for the surgical planning.

Dosimetric Comparison of Radiation Treatment Techniques for Breast Cancer : 3D-CRT, IMRT and VMAT (유방암 방사선치료 기법에 따른 선량 비교 : 3차원 입체조형치료, 세기 변조 방사선치료, 입체세기조절회전 방사선치료)

  • Lee, Bo-Ram;Lee, Sun-Young;Yoon, Myong-Geun
    • Journal of radiological science and technology
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    • v.36 no.3
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    • pp.237-244
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    • 2013
  • The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OED(Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ~ 2.02 Gy, 0.36 ~ 5.01 Gy, 0.25 ~ 2.49 Gy, 0.14 ~ 6.92 Gy, 0.03 ~ 2.02 Gy, 0.01 ~ 1.06 Gy, 0.25 ~ 6.08 Gy, 0.08 ~ 0.59 Gy, 0.01 ~ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT.

Preparation of YBa2Cu3O6+x Superconducting Wires Prepared by Pyrophoric Synthetic Technique (발화합성법에 의한 YBa2Cu3O6+x 초전도 선재의 제조)

  • Yang, Suk-Woo;Lee, Young-Min;Kim, Young-Soon;Park, Jeong-Shik;Kim, Chan-Joong;Hong, Gye-Won;Shin, Hyung-Shik
    • Applied Chemistry for Engineering
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    • v.9 no.7
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    • pp.1011-1017
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    • 1998
  • $YBa_2Cu_3O_{6+x}(Y123)-Ag$ high-Tc superconducting wires were fabricated by plastic extrusion technique using pyrophoric synthetic and mechanical mixing powder with and without Ag addition(20 wt.%). This method involves powder preparation, plastic paste making, die extrusion, binder burn-out and the sintering process. In order to fabricate a good-quality superconducting body, it is required to use homogeneous and fine-size power as a starting materials. $Y_2O_3-BaCO_3-CuO$ precursor powders with/without Ag addition were prepared both by pyrophoric synthetic(PS) and mechanical mixing(MM) method of raw powders. The formation kinetics of the powder mixtures into Y123 phase was investigated at various temperatures and times in air atmosphere. The powder prepared by PS method was more easily converted into a Y123 phase than the MM powder. The fine size and good chemical homogeneity of the powder prepared by PS method is attributable to the fast formation into a Y123 phase. The critical current density($J_c$) of the Y123-Ag superconducting wires made by plastic extrusion method were in the range of $150A/cm^2{\sim}230A/cm^2$. depending on the charateristics of starting material powders. $J_c$ of the wire prepared by pyrophoric synthetic powder with 20 wt.% Ag addition was $230A/cm^2$.

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Characteristics of Hydrogen Storage in Ti-Cr-Mo and Ti-Cr-V bcc Alloys (Ti-Cr-Mo계 및 Ti-Cr-V계 bcc 합금의 수소저장특성에 관한 연구)

  • You, J.H.;Cho, S.W.;Park, C.N.;Choi, J.
    • Journal of Hydrogen and New Energy
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    • v.16 no.2
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    • pp.122-129
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    • 2005
  • The characteristics of hydrogen storage have been investigated in the Ti-Cr-Mo and Ti-Cr-V ternary alloys with bcc structure. The alloys were melted by arc furnace and remelted 4-5 times for homogeneity. The lattice parameters, microstructures and phases of the alloys were examined by SEM, EDX and XRD, and the Pressure-Composition isotherms of the alloys were measured. From these data the relationship of the maximum and effective hydrogen storage capacities vs. chemical composition, lattice parameter and the radius of tetrahedral site were analyzed and discussed. The results showed that all of these alloy, in the range of the this study, had mainly bcc solid solutions with small amount of Ti segregation due to a lower melting point of Ti compared with other elements. Lattice parameters of the alloys were very near to the atomic average values of lattice parameters of the constituent elements. It was also found that maximum hydrogen storage capacities of the Ti-Cr-Mo alloys increased with increasing Ti content and the radius of tetrahedral site but the effective hydrogen storage capacities decreased after showing the maximum. The hydrogen storage capacities of the Ti-Cr-V alloys were almost same even though the V contens were quite different from alloy to alloy and this could be attributed to the almost same Ti/Cr ratio of the alloys. The maximum effective hydrogen storage capacity of the Ti-Cr-Mo alloys was revealed at Ti content of about 40${\sim}$50 at% and radius of tetrahedral site of 0.43${\sim}$0.45 nm. The Ti-Cr-V alloys showed the hydrogen storage capacities of 3.0 wt% and effective hydrogen storage capacities of 1.5 wt%.

A study on development of CRM by means of XRF analysis for fine ceramic ($BaTiO_3$) (티탄산바륨 소재의 XRF 분석용 CRM 개발에 관한 연구)

  • Kim, Young Man;Jeong, Chan Yee;Lim, Chang Ho;Song, Taek Yong;Lee, Dong Soo
    • Analytical Science and Technology
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    • v.9 no.4
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    • pp.382-391
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    • 1996
  • In this study, 12 different chemical species of fine ceramic($BaTiO_3$) were synthesized as the standard materials for the fast and accurate measurements of X-ray fluorescence spectrometry. Samples were diluted to sixteen times with the filling compound ($Li_2B_4O_7+LiBO_2$) in order to remove the matrix effect, and to get the convenient storage and homogeneity of ingredients. The matrix effects among the ingredients were corrected by the empirical coefficient method based on the Lucas-Tooth and Price model. The standard curve on 12 standard materials containing 15 elements were obtained by using X-ray fluorescence spectrometry at three different laboratories. The correlation factors of BaO, PbO, SrO, $Fe_2O_3$, $La_2O_3$, $SnO_2$, ZnO, $ZrO_2$, CaO indicated the relati vely good agreement over 0.995 among the three different laboratories. $SiO_2$ and $Al_2O_3$ showed the poor linearity because of their low fluorescence intensities.

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