• Journal of Conservation Science
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• v.37 no.5
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• pp.567-578
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• 2021

In this study, the physicochemical properties of 21 wall fragments and rooftile pieces excavated from Jeseoksa Dump-site were analyzed, and the possibility of heat exposure, such as the fire reported in the literature, was investigated by estimating the firing temperature. From the results, it was estimated that the rooftiles were composed of refined materials, and the walls were composed of materials having different particle sizes depending on the layer. Unlike ordinary rooftiles and walls, they exhibited an uneven surface with traces of bloating phenomenon in the cross section. It was estimated from the blackening of some portions that firing was not performed in a controlled state in a constant firing environment. In addition, the estimated firing temperature showed that the non-overfired rooftiles had endured a firing temperature of 900℃ or less, but the over-fired samples were subjected to a temperature of 1,000℃ or higher and were fired at a temperature higher than the manufacturing temperature at that time. Additionally, the rooftiles probably became defective during firing or molding at the time of production, but the non-overfired rooftiles exhibited an intact shape and showed the possibility of heat exposure due to fire. Therefore, the analytical results of this study confirm that the defective architectural components damaged by the fire, as reported in the literature, were discarded in the Jeseoksa dump-site.

• Computers and Concrete
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• v.6 no.3
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• pp.225-234
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• 2009

Dredged silt from reservoirs in southern Taiwan was sintered to make lightweight aggregates (LWA), which were then used to produce lightweight aggregate concrete (LWAC).This study aimed to assess the compressive strength and homogeneity of LWAC using ultrasonic-echo sensing. Concrete specimens were prepared using aggregates of four different particle density, namely 800, 1100, 1300 and 2650 kg/$m^3$. The LWAC specimens were cylindrical and a square wall with core specimens drilled. Besides compressive strength test, ultrasonic-echo sensing was employed to examine the ultrasonic pulse velocity and homogeneity of the wall specimens and to explore the relationship between compressive strength and ultrasonic pulse velocity. Results show that LWA, due to its lower relative density, causes bloating, thus resulting in uneven distribution of aggregates and poor homogeneity. LWAC mixtures using LWA of particle density 1300 kg/$m^3$ show the most even distribution of aggregates and hence best homogeneity as well as highest compressive strength of 63.5 MPa. In addition, measurements obtained using ultrasonic-echo sensing and traditional ultrasonic method show little difference, supporting that ultrasonic-echo sensing can indeed perform non-destructive, fast and accurate assessment of LWAC homogeneity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.2
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• pp.63-67
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• 2002

Langasite single crystal was grown by Xenon-arc floating zone method in mixutre of Af and $O_2$ gas atmosphere. Growing and rotation speed were 1.5 much and 15 rPm respectively. The grown crystal had a c-axis and color of orange. Composition of the grown crystal was $La_{3.10}Ga_{4.73}Si_{1.17}O_{14}$. Activation energy of the crystal was 0.23 eV and was PTC characteristics.

• Computers and Concrete
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• v.13 no.3
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• pp.325-342
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• 2014

The use of lightweight aggregate (LWA) instead of ordinary aggregate may make lightweight aggregate concrete, which possesses many advantages such as lightweight, lower thermal conductivity, and better fire and seismic resistance. Recently the developments of LWA have been focused on using industrial wastes as raw materials to reduce the use of limited natural resources. In view of this, the intent of this study was to apply Taguchi optimization technique in determining process condition for producing synthetic LWA by incorporating waste thin film transition liquid crystal displays (TFT-LCD) glass powder with reservoir sediments. In the study the waste TFT-LCD glass cullet was used as an additive. It was incorporated with reservoir sediments to produce LWA. Taguchi method with an orthogonal array L16(45) and five controllable 4-level factors (i.e., cullet content, preheat temperature, preheat time, sintering temperature, and sintering time) was adopted. Then, in order to optimize the selected parameters, the analysis of variance method was used to explore the effects of the experimental factors on the performances (particle density, water absorption, bloating ratio, and loss of ignition) of the produced LWA. The results showed that it is possible to produce high performance LWA by incorporating waste TFT-LCD glass cullet with reservoir sediments. Moreover, Taguchi method is a promising approach for optimizing process condition of synthetic LWA using recycled glass cullet and reservoir sediments and it significantly reduces the number of tests.

• Journal of Korean Academy of Nursing
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• v.34 no.8
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• pp.1395-1401
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• 2004

Purpose. To compare perimenstrual (premenstrual, menstrual, postmenstrual) symptoms by concurrent reporting using the Women's Daily Health Diary (WDHD) and by retrospective reporting using the Moos Menstrual Distress Questionnaire (MMDQ). Methods. A prospective and retrospective study was conducted among 31 Korean women, aged 27 to 48 yrs, living in the USA. Results. On the prospective report using the WDHD, the most severe complaints were fatigue or tiredness ($1.48{\pm}.98$), sensation of weight gain ($.88{\pm}98$), increased appetite ($.79{\pm}.96$) in premenstrual phase, fatigue or tiredness ($1.34{\pm}.85$), backaches ($1.06{\pm}.79$), and bloating or swelling of the abdomen ($.93{\pm}.86$) during the menstrual phase. On the retrospective report using the MMDQ, the most severe complaints during the premenstrual phase were fatigue ($2.26{\pm}1.65$), irritability ($2.06{\pm}1.48$), and backaches ($1.97{\pm}1.68$) and during the menstrual phase backaches ($2.35{\pm}1.62$), fatigue ($2.29{\pm}1.75$), and cramps ($2.23{\pm}1.80$). According to both measurements of PMS symptomology during the premenstrual and menstrual phases, the most frequently reported symptom was fatigue or tiredness. Highly rated symptoms on the MMDQ and on the WDHD were found to be similar. Conclusion. The WDHD was found to be suitable for daily prospective PMS assessment, which will be necessary for the screening and management of women with severe PMS.

• The korean journal of orthodontics
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• v.13 no.1
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• pp.95-103
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• 1983

By observing the lateral cephalometric radiograms of the Naso-pharynx of the mouth breatheres with adenoid hyperplasia, orthodontists could use the 'discriminant function' as the supplementary diagnotic aid for the malocclusion cases with mouth bloating. The purpose of this study was to ustilize the 'discriminant function' as the indicator to remove the etiologic factor producing the relapse. The author used the 19 boys and 20 girls, who were the nasal-breathers with normal occlusion as the control group, and 16 boys and 20 girls, who were the mouth breathers with adenoid hypaplasia and malocclusion. The age of the both groups was ranged from 12ys to 15ys. Results were as following; 1. There was the difference in the bony structure of Naso-pharynx between the mouth-breathers nasal-breathers. 2. IMRA of the mouth breathers was smaller than the nasal breathers'. 3. The mouth-breathers had the skeletal open bite tendency. 4. Discriminant function: $$D_i=9.85374+ax_2+bx_4+cx_6+dx_7+ex_8$$ a = -0.1211273 b = 0.5908992 c = -1.508446 d = -1.541869 e = 1.404478.

• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.246-252
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• 2016

Complex designed silica-based ceramic cores were fabricated by ceramic injection molding. Slow heating rate (0.2K/min) for debinding restrained bloating on the surface of ceramic cores. To investigate effect of sintering conditions on mechanical properties of ceramic cores, green bodies were sintered at temperatures in a range from $1150^{\circ}C$ to $1400^{\circ}C$ for various dwelling times (6 h to 48 h). Sintering above $1300^{\circ}C$ for 12 h and dwelling time over 24 h at $1200^{\circ}C$ reduce the flexural strength and increase the linear shrinkage of ceramic cores. Cristobalite, formed by high sintering temperature or long dwelling time, induces reduction of mechanical properties due to its phase transformation, which is accompanied by volume contraction and microcracking. Ceramic core sintered at $1200^{\circ}C$ for 12 h endured wax patterning and shell molding, and was manufactured successfully.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.61-66
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• 2010

Silicon nitride is widely used as an engineering ceramics because it has high strength, abrasion resistance and corrosion resistance even at high temperature. However, machining of silicon nitride is difficult due to its high hardness and brittleness. Laser assisted machining(LAM) allows effective cutting using CBN tool by locally heating the cutting part to the softening temperature of YSiAlON using the laser beam. The effect of preheating depending on process parameters were studied to find out the oxidation mechanism. If silicon nitride is sufficiently preheated, the surface is oxidized and $N_2$ gas is formed and escapes from the material, thereby making the cutting process more advantageous. During laser preheating process before machining, high temperature results in strong oxidation which makes the bloating, silicate layers and micro cracks. Using the results of these experiments, preheating characteristics and oxidation behavior were found out.

• Journal of the Korean Society of School Health
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• v.9 no.2
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• pp.223-237
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• 1996

This study was conducted in order to contribute to female student health by providing fundamental data for health instruction and health counsel. The purpose of this study is to determine the frequency of PMS by a menstrual distress questionnaire, and determine sex-identity factors related to PMS. The data were collected by a questionaire conducted from December 1,1995 to December 20, 1995. The subjects of research were 1,102 high school students in Seoul. The data analyzed was done using the SPSS PC+, and the results were as follows; 1. The perceived subjective symptoms were clusted behavioral change, negative affects, pain, impaired concentration, water retention and autonomic reactions. The most common symtoms during the period of 2 to 10 days before menses were vaginal discharge(79%), back pain(70.4%), nervous tension(60.8%), fatigue(56.2%), abdominal bloating(54.5%), mood change(52.8), pelvic pain(46.8%), resistance to study(45.9) and talking(43.3). 2. There was a significant correlation between the clusters symptoms; negative affects and behavioral changes(r=.9326, p=.000), behavioral changes and impaired concentration (r=.8572, p=.000), negative affects and impaired concentration(r=.8411, p=.000) and autonomic reaction and pain(r=.7267, p=.000). 3. Sex-identity factors were related to PMS ; perception of the female(F=5.1811, p=.006) and pregnancy concerns (T=3.54, p=.000).

• Journal of Korean Clinical Nursing Research
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• v.14 no.1
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• pp.61-70
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• 2008

Purpose: Women with gynecologic cancer often experience various physical and psychological symptoms relating to the cancer and its treatment. The purpose of this study was to identify symptom clusters. Method: A survey was conducted on 184 women with diagnoses of cervical, ovarian or endometrial cancer. Fifty symptoms were assessed for prevalence, severity and interference, and symptom clusters were identified. Cluster analysis was done using SPSS version 12.0. Results: Fatigue was identified as the most prevalent symptom (81.52%), lack of vaginal lubrication (2.26) as the most severe symptom, and lack of vaginal lubrication as the most interfering one (2.15). Identified six clusters were: Anorexia-pain cluster (loss of appetite, taste change, weight loss, appearance change, alopecia, weakness, pain), Fatigue cluster (lack of concentration, lack of memory, fatigue, dry mouth), Urinary-bowel distress cluster (urinary difficulty, constipation), Abdominal discomfort cluster (lower abdominal pain, abdominal pain, bloating), Emotional distress (sadness, anxiety-worry, nervousness, restlessness), and Menopausal cluster (sweating, hot flush, fever). Conclusion: The result of this study provides fundamental data to health care professionals in developing interventions for effective symptom management for women with gynecologic cancer by understanding identified 6 symptom clusters.