• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.208-241
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• 2010

This study was conducted to examine the chronology of Taesil Seokham(Taesil Stone Boxes) stored in Taesil of the Joseon Palace and classify the styles to discuss how these boxes have developed. By doing so, this study defined the archaeological styles of taesil seokhams in the chronological order. Although taesil seokhams are placed when taesil are first created, they do not have any texts engraved on them and it is difficult to gain information only from examining taesil seokham. However, Taejiseok(memorial stones buried in Taesil) and Agibi(gravestones buried in Taesil) were created along with taesil. These resources were examined and compared with literature records to find when each taesil seokhams was created. The critical elements to consider for the chronological arrangement were both the cover and container of the boxes and the transition of their style could be classified into four major stages. In detail, the Joseon Dynasty's taesil seokhams initially inherited the style of the Goryeo Dynasty to be formed into rectangular boxes. Through the transition of the mid and late 15th Century, the semi-circular cover with cylindrical container became the popular style in the late 15th Century. In the late 16th Century, the style of the previous period was further developed to add some decorative elements, such as projecting ornaments, but the ornaments were added for functional purposes rather than artistic purposes. However, the style went back to the semi-circular cover with cylindrical container in the early 17th Century. From the mid 17th Century, various styles appeared with ornaments only on the cover, cone-shaped cover with no ornament, or mortar-like container. However, a new style of cone-shaped cover with ornament emerged between the early and mid 18th Century and continued to stay until the mid 18th Century. In the mid 18th Century, the cover remained unchanged, but the container became a keyhole-shaped space with one side forming a "ㄷ" shape. However, in the late 18th Century, the most typical style of the semi-circular cover with cylindrical container reappeared to show that this is the most universal style. Last, in the mid 19th Century, the cover changed from semi-circular to rectangular with flat top. After this, the taesil seokhams began to disappear. In terms of style, it can be classified into four stages. In the early Joseon Dynasty, the taesil seokhams were underdeveloped and inherited the style of the Goryeo Dynasty (Stage I; 1401~mid-15C), but Joseon's unique style began to develop from the late 15th Century (Stage II; 1477~1641). After that, partial ornaments were added for adornment (Stage III; 1660~1754), but the typical style reappeared in the late 18th Century to finally degrade in the late Joseon Dynasty of the mid 19th Century (Stage IV; 1790~1874). This arrangement of style and chronology would greatly help archaeologists anticipate the time and owner of taesil seokhams even if only taesil seokhams are discovered without any records. * Tae(胎) : Placenta and umbilical cord * Taesil(胎室) : A facility(chamber) of burying Tae(胎) in rite when royal descendants are born.

• The Science & Technology
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• v.32 no.6 s.361
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• pp.16-17
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• 1999

유전자치료시대의 막이 오르면 태아의 결함이 바로잡는 것은 물론 태어날 아기에게 장수와 높은 지능지수(IQ) 그리고 미모와 좋은 성격까지 얹어줄 수 있는 길이 열릴지 모른다.

• Journal of the Korean School Mathematics Society
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• v.23 no.1
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• pp.25-44
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• 2020

This study investigated the representation and algorithms of western mathematics reflected on the algebra domains of Chosun-Sanhak in the 18th century. I also analyzed the co-occurrences and replacement phenomenon between western algorithms and traditional algorithms. For this purpose, I analyzed nine Chosun mathematics books in the 18th century, including Gusuryak and Gosasibijip. The results of this study are as follows. First, I identified the process of changing to a calculation by writing of western mathematics, from traditional four arithmetical operations using Sandae and the formalized explanation for the proportional concept and proportional expression. Second, I observed the gradual formalization of mathematical representation of the solution for a simultaneous linear equation. Lastly, I identified the change of the solution for square root from traditional Gaebangsul and Jeungseunggaebangbeop to a calculation by the writing of western mathematics.

• Journal for History of Mathematics
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• v.22 no.4
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• pp.15-28
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• 2009

In this paper, we study the 17th Century Chosun's mathematics book ${\ll}$Muk Sa Jib San Beob${\gg}$ written by Chosun's mathematician Kyeong Seon Jing. Our study of thebook shows the ${\ll}$Muk Sa Jip San Beop${\gg}$ as an important 17th Century mathematics book and also as a historical data showing the mathematical environment of 17th Century Chosun.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.216.1-216.1
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• 2014

Closed drift ion source는 그 특성으로 인하여 강판 표면처리, 금속 표면 산화막 형성, 폴리머 혹은 기타 표면 개질 등 다양한 분야에서 사용이 되고 있다. 다양한 환경에서 사용 되는 소스의 특성으로 인하여 각기 다른 공정에 대한 최적의 특성이 요구 되며, 이러한 공정 환경에 맞춘 소스를 설계하기 위해서 ion source내 전극의 구조 및 자기장 세기 등 이온소스의 구조적 특성에 대한 연구가 필요하게 된다. 본 연구에서는 선형 이온소스의 구조 설계를 위한 실험을 소형(이온빔 인출 슬릿 직경: 60 mm) 이온빔 인출 장치를 제작하여 전극 구조에 따른 방전 특성을 우선적으로 평가를 실시하여 소형 이온빔 인출 장치에서 도출된 결과를 바탕으로 0.3 m급 linear closed drift ion source 설계에 대한 변수를 조사 하였다. 실험은 양극-음극(C-A) 간 간격 및 음극 슬릿(C-C) 간격 그리고 자기장 세기 조건에서 방전 전류 및 인출 이온빔 전류량 측정하였으며, 이 결과를 전산모사 결과와 비교 하였다. 방전전압 1~5 kV, 가스유량 10~50 sccm 조건에서 Ar 이온빔 방전 특성을 평가한 결과, 양극-음극(C-A) 간격이 넓을수록, 음극-음극(C-C) 간격이 좁을수록 방전 전류량이 증가함을 확인 하였다. 또한, 공정 가스 압력 및 자기장 세기 변화에 따른 1~5 kV의 방전 전압에 대한 방전 특성의 관찰 결과, 압력 및 자기장 변화에 따라서 방전 전류의 변화를 관찰 할 수 있었으며, 이에 대한 결과를 통하여 이온 소스 구조 내부에서의 방전 영역에 대한 압력과 자기장 세기에 대한 영향을 분석 할 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.429-429
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• 2012

본 연구에서는 분자선 박막 성장법(MBE)으로 성장된 GaAs single junction solar cell의 광학적 특성 변화를 photoreflectance (PR)을 이용하여 연구하였다. 본 연구에 사용된 태양전지 구조는 n+-GaAs (100)기판 위에 n+-GaAs buffer를 200 nm 성장 후 그 위에 i-GaAs 250 nm와 p+-GaAs 200 nm 성장 하였다. 상온에서 PR 측정 결과, 변조빔 세기가 증가할수록 Franz-Keldysh oscillation (FKO)의 주파수가 증가하는 현상이 관측되었다. 이는 변조빔의 세기가 강해질수록 광케리어수의 증가로 인한 스크리닝 효과에 기인한 것으로 사료된다. 아울러 Fast Fourier transform (FFT) 결과, 변조빔의 세기가 약할 때는 세 개의 주된 피크가 나타났으며, 이러한 현상은 GaAs에서 가전자대의 heavy hole (HH)과 light hole (LH)의 전이로 인해 나타나는 FKO 신호가 중첩되어 HH과 LH 피크가 HH과 HH-,LH과 LH-로 나뉘어진 것으로 사료된다. 여기광의 세기가 $1.40mW/cm^2$ 이상일 때는 주된 세 개 피크 이외에 부가적인 피크가 상대적으로 고 주파수 영역에서 관측되었다. 이러한 고주파수 영역에서의 나타나는 FKO 주파수는 시료의 내부전기장이 여기광의 세기가 증가할수록 감소하는 결과로 사료된다.

• Progress in Medical Physics
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• v.24 no.3
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• pp.154-161
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• 2013

This study assessed compared photon and proton treatment techniques, such as intensity modulated radiation therapy (IMRT), uniform scanning proton therapy (USPT), and intensity modulated proton therapy (IMPT), for a total of 10 prostate cancers. All treatment plans delivered 70 Gy to 95% of the planned target volume in 28 fractions. IMRT plans had 7 fields for the step and shoot technique, while USPT and IMPT plans employed two equally weighted, parallel-opposed lateral fields to deliver the prescribed dose to the planned target. Inverse planning was then incorporated to optimize IMPT. The homogeneity index (HI) and conformity index (CI) for the target and the normal tissue complication probability (NTCP) for organ at risk (OAR) were calculated. Although the mean HI and CI for target were not significantly different for each treatment techniques, the NTCP of the rectum was 2.233, 3.326, and 1.707 for IMRT, USPT, and IMPT, respectively. The NTCP of the bladder was 0.008, 0.003, and 0.002 respectively. The NTCP values at the rectum and bladder were significantly lower using IMPT. Our study shows that using proton therapy, particularly IMPT, to treat prostate cancer could be beneficial compared to 7-field IMRT with similar target coverage. Given these results, radiotherapy using protons, particularly optimized IMPT, is a worthwhile treatment option for prostate cancer.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.583-592
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• 2018

In this study, plans to apply 3D conformal radiotherapy, intensity modulated radiotherapy, and volumetric intensity modulated arc radiotherapy to esophageal cancer radiotherapy were compared. In particular, arc therapy was applied to reduce irradiated volume and spread of low-dose during intensity modulated radiation therapy and volumetric intensity modulated arc radiotherapy by limiting part of irradiated angle, in order to compare target doses and dose for surrounding normal tissues of the two methods and those of 3D conformal radiotherapy. No significant difference in target dose was found among the three methods. The 5 Gy volume(V5) of the lung showed 56.53% of conformal radiotherapy, 52.03% of intensity modulated radiotherapy, and 47.84% of volumetric modulated arc therapy(CRT-IMRT p=0.035, CRT-VMAT p<0.001, IMRT-VMAT p<0.001). The 10 Gy volume(V10) showed a significant difference in conformal radiotherapy 35.12%, intensity modulated radiotherapy 34.04%, and volumetric modulated arc radiotherapy 33.28%, showing significant difference in intensity modulated radiotherapy(p=0.018), volumetric modulated arc therapy(p=0.035), no significant difference in dose was found at 20 Gy volume. The mean dose and 20 Gy volume of the heart were not significantly different according to the treatment plan, but the 30 and 40 Gy volumes were 37.16% and 22.46% in the volumetric modulated arc radiotherapy, showing significant differences(p=0.028) in comparison with conformal radiotherapy. It is believed that, by limiting part of the irradiated angle during intensity modulated radiotherapy and volumetric intensity modulated arc radiotherapy, the irradiated volume and, thereby, the 5-10 Gy area and toxicity of the lung can be reduced while maintaining dose distribution of the target dose.

• The Korean Journal of Quaternary Research
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• v.16 no.2
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• pp.33-38
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• 2002

28 direction of the past Korean geomagnetic field were determined by archaeomagnetic measurements of 734 oriented samples, collected from baked earths of remains in the southern Korea. These data cover periods of A.D. 39C, A.D. 1317 and A.D. 15-l6C. It is noted that Korean geomagnetic field data in 5-6C arc similar to those of contemporary Japanese geomagnetic field, but Korean geomagnetic field data in A.D. 3-4C deflect more easterly than contemporary Japanese geomagnetic field. The observed large difference of geomagnetic field direction between Korea and Japan suggests the existence of a prominent local geomagnetic anomaly in the vicinity of Japan and Korea in the period of A.D. 3-4C. An approximate figure of Korean archaeomagnetic secular curve for the periods of A.D. 3-6C and A.D. 7-9C was obtained. This curve is sure to be helpful for Korean archaeology to data the last firing of baked earths accompanied with no relics.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.100-108
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• 2020

20th century music has been recognized as disconnected. Some criticized that it is not music. This controversy has been continued over decades in music history. This study applied Darwin's evolutionary theory to John Cage's 4'33", the most popular music in 20th century and tried to prove musical continuity embedded in it. 4'33" has always been a subject of controversy because it has no sound. However, the study found out that 4'33" has the common musical factor, the rest. 4'33" can be interpreted as the variation of the rest in evolutionary view. The rest has undergone a variety of variations in form and meaning since the beginning of the musical notation and was suitable for a new musical environment changed in 20th century. In the evolutionary view, 4'33" is evolved music, not disconnected.