• 보존과학회지
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• 제37권5호
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• pp.567-578
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• 2021

본 연구는 제석사지 폐기유적에서 출토된 벽체 및 기와 편 21점의 물리화학적 특성을 확인하고, 소성 온도를 추정함으로써 문헌 기록상으로 확인되는 화재로 인한 피열 가능성을 확인하였다. 분석 결과, 기와는 수비된 재료를 사용하였고, 벽체는 층위에 따라 서로 다른 입도의 재료를 사용하여 제작한 것으로 추정된다. 과소성된 시료의 경우, 일반적인 기와나 벽체와 달리 단면에 블로팅(bloating) 현상과 함께 고르지 못한 표면을 가지며, 일부분이 검게 그을린 것을 보아 일정한 소성 환경에서 제어된 상태로 고른 소성이 이루어지지 않은 것으로 판단된다. 또한 소성온도 추정 결과, 과소성되지 않은 기와는 900℃ 이하의 소성온도를 가졌으나 과소성된 시료는 1000℃ 이상의 열을 받았던 것으로 보이며, 당시 기와의 제작 온도보다 고온으로 소성되었음 보여준다. 또한, 불량품기와는 제작 당시 소성이나 성형 과정에서 불량품이 된 것으로 보이지만 과소성된 기와의 경우에 온전한 기와 형태를 가지면서 과피열 양상을 보여 화재로 인한 피열 가능성을 보여준다. 이러한 결과들을 종합적으로 고찰하였을 때, 익산 제석사지 폐기유적은 기록상 존재하는 화재로 인해 폐기된 건축 부재를 보관하던 장소였던 것으로 추정된다.

• Computers and Concrete
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• 제6권3호
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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.

• 한국결정성장학회지
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• 제12권2호
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• pp.63-67
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• 2002

부유대역법을 이용하여 직경 Langasite 단결정을 Ar과 $O_2$가 혼합된 가스의 분위기에서 성장시켰으며, 그때 성장속도는 각각 1.5 mm/hr, 회전속도는 15rpm이었고, 성장된 결정은 투명한 짙은 오렌지색을 가졌다. 성장된 결정은 c 축 방향으로 성장되었으며, 길이 방향의 조성변동이 없이 성장한 것을 확인할 수 있었고, 성장된 결정은 $La_{3.10}Ga_{4.73}Si_{1.17}O_{14}$의 조성을 가지고 있었다. 500nm 부근의 흡수밴드는 성장된 결정의 오렌지빛과 관계가 있는 것을 확인할 수 있었으며, 계산된 Langasite의 활성화에너지는 0.23eV이었고, $300^{\circ}C$ 이상의 온도에서 PTC의 특성을 나타내는 것을 알 수 있었다.

• Computers and Concrete
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• 제13권3호
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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.

• 대한간호학회지
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• 제34권8호
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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.

• 대한치과교정학회지
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• 제13권1호
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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.

• 한국세라믹학회지
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• 제53권2호
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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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• 제28권4호
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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.

• 한국학교보건학회지
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• 제9권2호
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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).

• 임상간호연구
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• 제14권1호
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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.