• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.389-396
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• 2017

Peridynamics has been widely used in the dynamic fracture analysis of brittle materials. Recently, various crack patterns(compact region, floret, Hertz-type crack, etc.) of multilayered glass structures in experiments(Bless et al. 2010) were implemented with a bond-based peridynamic simulation(Bobaru et al.. 2012). The actual glass layers are bound with thin elastic interlayer material while the interlayer is missing from the peridynamic model used in the previous numerical study. In this study, the peridynamic interlayer modeling for the multilayered structures is proposed. It requires enormous computational time and memory to explicitly model very thin interlayer materials. Instead of explicit modeling, fictitious peridynamic particles are introduced for modeling interlayer materials. The computational efficiency and accuracy of the proposed peridynamic interlayer model are verified through numerical tests. Furthermore, preventing penetration scheme based on short-range interaction force is employed for the multilayered structure under compression and verified through parametric tests.

• Journal of Conservation Science
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• v.28 no.1
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• pp.87-94
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• 2012

This study was focused on digital restoration and surface depth modeling applying the three-dimensional laser scanning system of the Haeundae Stone Inscription. Firstly, the three-dimensional digital restoration carried out acquiring of point cloud using wide range and precision scanner, thereafter registering, merging, filtering, polygon mesh and surveyed map drawing. In particular, stroke of letters, inscribed depth and definition appearing the precision scanning polygon was outstanding compared with ones of the wide range polygon. The surface depth modeling completed through separation from polygon, establishment of datum axis, selection of datum point, contour mapping and polygon merging. Also, relative inscribed depth (5~17mm) and outline by the depth modeling was well-defined compared with photograph and polygon image of the inscription stone. The digital restoration technology merging wide range and precision scanning restored the total and detailed shape of the Stone Inscription quickly and accurately. In addition, the surface depth modeling visibly showed unclear parts from naked eye and photograph. In the future, various deteriorations and surrounding environment change of the Stone Inscription will be numerically analyze by periodic monitoring.

• Journal of the Korea Concrete Institute
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• v.24 no.3
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• pp.285-292
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• 2012

Fixed connection is generally used for beam and column connections of concrete structures, but significant damages at the connection due to severe earthquakes have been reported. In order to reduce damages of the connection and improve seismic performance of the connection, several innovative connections have been suggested. One newly proposed connection type allows a rotation of the connection for applications in rotating or rocking beams, columns, and shear walls. Such structural elements would provide a nonlinear lateral force-displacement response since their contact depth developed during rotation is gradually reduced and the stress across the sections of the elements is non-linearly distributed around a contact area, which is called an elastic hinge region in the present study. The purpose of the present study is to define the elastic hinge region or length for the rocking columns, through investigating the cross-sectional stress distribution during their lateral behavior. Performing a finite element analysis (FEA), several parameters are considered including axial load levels (5% and 10% of nominal strength), different boundary conditions (confined-ends and cantilever types), and slenderness ratios (length/depth = 5, 7, 10). The FEA results showed that the elastic hinge length does not directly depend on the parameters considered, but it is governed by a contact depth only. The elastic hinge length started to develop after an opening state and increased non-linearly until a rocking point(pre-rocking). However, the length did not increase any more after the rocking point (post-rocking) and remained as a constant value. Half space model predicting the elastic hinge length is adapted and the results are compared with the numerical results.

• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.115-132
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• 2000

Eggshell strength and eggshell pigmentation are described in this paper since these are needed for quality egg production. A strong eggshell is determined by the components of the shell (cuticle, true shell and membranes) as well as the proper function of the gastrointestinal tract, the shell gland, the Kidneys and the endocrine system. When the puller reaches sexual maturity, the medullary bone must be ready for the laying hen at the peak egg shell formation. The amount of calcium in the layer diet, sources of calcium feed, the ratio of calcium and phosphorus in the layer diet, adequate levels of vitamin D and the dietary mineral (electrolyte) balance in the body fluid are important factors along with the levels of other nutrients. Biological, environmental and managerial factors such as the age of laying flock, temperature and humidity of the hen house, bird strain, disease, egg collection through transportation and others and influence the shell breakage at various stages of movement of the eggs from the producer to the consumer. The pigments present in eggshells are protoporphyrin-Ⅸ, biliverdin-Ⅸ and its zinc chelate and occasional traces of coproporphyrin-Ⅲ. However, there are several causes of changes in eggshell pigmentation such as the age of hen, disease, drugs and surface defects due to abnormal post-cuticular deposits.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.456-456
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• 2010

CMOS 소자가 서브마이크론($0.1\;{\mu}m$) 이하로 스케일다운 되면서 단채널 효과(short channel effect), 게이트 산화막(gate oxide)의 누설전류(leakage current)의 증가와 높은 직렬저항(series resistance) 등의 문제가 발생한다. CMOS 소자의 구동전류(drive current)를 높이고, 단채널 효과를 줄이기 위한 가장 효율적인 방법은 소스 및 드레인의 얕은 접합(shallow junction) 형성과 직렬 저항을 줄이는 것이다. 플라즈마 도핑 방법은 플라즈마 밀도 컨트롤, 주입 바이어스 전압 조절 등을 통해 저 에너지 이온주입법보다 기판 손상 및 표면 결함의 생성을 억제하면서 고농도로 얕은 접합을 형성할 수 있다. 그리고 얕은 접합을 형성하기 위해 주입된 불순물의 활성화와 확산을 위해 후속 열처리 공정은 높은 온도에서 짧은 시간 열처리하여 불순물 물질의 활성화를 높여주면서 열처리로 인한 접합 깊이를 얕게 해야 한다. 그러나 접합의 깊이가 줄어듦에 따라서 소스 및 드레인의 표면 저항(sheet resistance)과 접촉저항(contact resistance)이 급격하게 증가하는 문제점이 있다. 이러한 표면저항과 접촉저항을 줄이기 위한 방안으로 실리사이드 박막(silicide thin film)을 형성하는 방법이 사용되고 있다. 본 논문에서는 (100) p-type 웨이퍼 He(90 %) 가스로 희석된 $PH_3$(10 %) 가스를 사용하여 플라즈마 도핑을 실시하였다. 10 mTorr의 압력에서 200 W RF 파워를 인가하여 플라즈마를 생성하였고 도핑은 바이어스 전압 -1 kV에서 60 초 동안 실시하였다. 얕은 접합을 형성하기 위한 불순물의 활성화는 ArF(193 nm) excimer laser를 통해 $460\;mJ/cm^2$의 에니지로 열처리를 실시하였다. 그리고 낮은 접촉비저항과 표면저항을 얻기 위해 metal sputter를 통해 TiN/Ti를 $800/400\;{\AA}$ 증착하고 metal RTP를 사용하여 실리사이드 형성 온도를 $650{\sim}800^{\circ}C$까지 60 초 동안 열처리를 실시하여 $TiSi_2$ 박막을 형성하였다. 그리고 $TiSi_2$의 두께를 측정하기 위해 TEM(Transmission Electron Microscopy)을 측정하였다. 화학적 결합상태를 분석하기 위해 XPS(X-ray photoelectronic)와 XRD(X-ray diffraction)를 측정하였다. 접촉비저항, 접촉저항과 표면저항을 분석하기 위해 TLM(Transfer Length Method) 패턴을 제작하여 I-V 특성을 측정하였다. TEM 측정결과 $TiSi_2$의 두께는 약 $580{\AA}$ 정도이고 morphology는 안정적이고 실리사이드 집괴 현상은 발견되지 않았다. XPS와 XRD 분석결과 실리사이드 형성 온도가 $700^{\circ}C$에서 C54 형태의 $TiSi_2$ 박막이 형성되었고 가장 낮은 접촉비저항과 접촉저항 값을 가진다.

• Journal of Conservation Science
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• v.35 no.3
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• pp.217-225
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• 2019

The chimi(ridge-end tile) of Wangheungsa temple is the oldest in our country. The upper part of the chimi was excavated from the southern side of Wangheungsa temple and the lower part from the northern side. These parts are considered to be portions of the same chimi, because they are similar in shape and are excavated from two sides of the same temple structure. However, the original shape of the chimi cannot be determined owing to substantial deterioration. Hence, in this study, replicas of the deteriorated chimi portions of Wangheungsa temple were fabricated by employing 3D scanning technology and the computer numerical control machining method. While observing the bending phenomenon of the chimi, the proposed model was warped realistically on the basis of the bending direction of the actual chimi. Consequently, the restoration process was modified several times. The results indicated that no gaps can be found between the upper and lower parts, and the corresponding patterns connect naturally. Furthermore, the proposed method is contactless, safe, operable, reproducible, and appropriate for restoration of artifacts. Additionally, the modeling data is semi-permanent. Hence, if modelling data is appropriately applied as per the characteristics of artifacts, it can be utilized in various fields such as virtual exhibitions, hands-on exhibitions, cultural heritage restoration, and production of teaching aids and souvenirs.

• The Korean Society of Law and Medicine
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• v.24 no.3
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• pp.105-124
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• 2023

Modern society is facing an unstable environment due to unexpected accidents and hazardous situations. For example, incidents such as the collapse of the Bundang Bridge and the crushing accident in Itaewon could serve as examples. In addition to these, critical emergencies like sudden cardiac arrests and strokes frequently occur, requiring swift actions and smooth transfers to specialized medical institutions for effective responses. In response to these risks, the country has been establishing various systems to protect the lives and safety of its citizens. Among these, the 119 First Aid Activities plays a crucial role within the emergency medical system. Its goal is to promptly respond to critical emergency situations involving severe trauma patients or patients with serious illnesses, minimizing damage and safeguarding lives by swiftly transferring them to emergency medical institutions for specialized treatment. The core activity related to this is emergency rescue operations. In particular, the 119 First Aid system serves as a crucial institution responsible for the hospital transportation of emergency patients. However, rescue personnel still encounter cases of interference with their activities during their duties. Despite efforts from the police, these interference cases persist, and they share similarities with the crime of obstructing official duties. Interference with emergency activities exhibits a comparable nature to instances such as physical assaults and equipment damage against emergency medical practitioners working within the emergency medical system. Therefore, a comprehensive understanding and improvement efforts regarding the issues of interference that arise during the process of emergency medical activities, including the 119 First Aid system, are necessary. The solution to these problems is to establish and improve the conditions for obstruction of first aid activities, focusing on the "Framework Act on Firefighting" and the "Act on 119 Rescue and Emergency."

• Journal of Radiation Protection and Research
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• v.32 no.4
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• pp.140-156
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• 2007

This research was performed to investigate the morphological changes of folliculus ovary according to the radiation dose. The whole body radiation of 200 cGy, 400 cGy, and 600 cGy was given to the each groups of 5 months-aged female mouse. Various staining methods used in this research are: Hematosylin-Eosin method, and immunohistochemistrical methods using BrdU, TUNEL, p53, p21, PCNA and inhibin. The minute structural changes of folliculus ovary were observed through an electron microscope with high magnification. The morphological changes of growing folliculus ovary became distinct as the dose of X-rays increased. Especially, the nuclei of granular cells showed manifest condensation and the changes of the transparent zone were distinct. As a result of histochemical reaction according to Masson's trichrome method and reticular fiber method, the changed granular cells, the deformed basilar membrane of folliculus ovary and the abnormal arrangement of the reticular fiber were observed. In the reaction of BrdU, the granular cells of normal folliculus ovary with positive reaction rapidly decreased according to the increase of the dose of X-rays. In TUNEL study, granular cells showing positive reaction in retarded folliculus ovary were expanded to growing folliculus ovary and primordial folliculus ovary according to the increase of the dose of X-rays. In case of 600 cGy of X-rays, oocyte underwent apoptosis. In p53 immunohistochemistry, p53 manifested to be stronger as the dose of X-rays increased. p53 reactivity was manifested distinctively in all cells comprising folliculus ovary following irradiation of 600 cGy. p21 was manifested in granular cells of folliculus ovary and showed very positive reaction around follicular antrum according to the increase of the dose of X-rays. In PCNA, positive reaction was manifested in growing folliculus ovary, mature folliculus ovary and primordial folliculus ovary, but the extent of the reaction decreased as the dose of the X-rays decreased. The finding that the reaction of granular cells around folliculus ovary was stronger than that near follicular membrane indicates that what was damaged first by X-ray was the cells near folliculus ovary and follicular antrum. The reactivity of $inhibin-{\alpha}$ showed difference according to the growing stage of folliculus ovary: $inhibin-{\alpha}$ showed the most strong reaction in mature folliculus ovary with follicular antrum. There was strong reaction in granular cells around follicular membrane but $inhibin-{\alpha}$ did not occur at all in theca cells comprising follicular membrane. $Inhibin-{\alpha}$ in ovary tissue exposed to 400 cGy of X-rays was manifested more strongly than in ovary tissue exposed to 600 cGy of X-rays, which was related to the phenomenon that granular cells of mature folliculus ovary underwent necrosis or apoptosis increasingly due to X-rays. In an electron microscope with high magnification, nuclei and protoplasm of granular cells in growing folliculus ovary abruptly underwent minute structural changes according to the increase of dose of X-rays. Cell residue, by-product of cell decease, neutrophil and macrophage around follicular antrum were observed. The minute structural changes in granular cells showed typical characteristics of apoptosis: the increase of electronic density due to nuclear condensation, fragmentation of nuclei and atrophy of protoplasm. Necrosis of cells was identified but it was not so remarkable. Macrophage with apoptotic bodies was scattered. Proportional to the radiation dose, we found that the generation of heterogeneous substance of normal ovary texture's follicular fluid, the emergence of dyeing characteristic in the basilar membrane of folicle, the generation of apoptosis, and the transformation of macrophages, etc. From this results, we can infer the possible radiation hazard on the ovary of cervix cancer patient with radiation therapy.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.169-175
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• 2006

The objective of this study was carried out to examine the polar body extrusion of in vitro matured porcine follicular oocytes as a non-invasive marker of oocyte quality to know the developmental competence in advance. The porcine oocytes matured for 48 hours were examined the polar body extrusion and some parts were stained. The examined oocytes were matured for additional $16{\sim}18$ hours and activated with 7% ethanol and cultured in $5{\mu}g/ml$ cytochalasin B for 5 hours for diploid formation. The treated oocytes were washed and cultured for 7 days. The polar body extrusion and degeneration rates were varied with $9.9{\sim}52.4%$ and $21.4{\sim}61.8%$ by repetition. The polar body extruded oocytes were shown the polar body chromosome and metaphase II plate by staining. However the non-extruded oocytes were shown expanded nucleus with 39.1%, premature chromosome condensation with 19.6%, metaphase I plate with 10.9 %, metaphase II with 13%, condensed chromatin with 6.5%, and absent nuclear material with 8.7%. The oocytes that were not examined for the polar body extrusion were cleaved 45.0%, and developed to blastocyst stage with 11.3%. In examined oocytes for polar body extrusion,. the polar body extruded oocytes were cleaved 94.2% and developed with 42.5%. This result suggests that discarding of the degenerating oocytes and oocytes that not extruded polar body will be effective for experiments of culturing effect in porcine embryos and embryo biotechnology.

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.189-197
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• 2020

This study was conducted to compare the production performance and stress response of chickens kept in the conventional cages and floor pens. 491 female White Leghorns were used in this study, and their production characteristics and stress response indicators were analyzed from 34 to 43 weeks of age. The results showed that there was no significant difference in survival rate, hen-day egg production, and body weight between the chickens kept in the conventional cages and those kept in the floor pens. The chickens kept in the conventional cages had a significantly higher egg weight and egg quality compared with those kept in the floor pens (P<0.01). The amount of telomeric DNA in lymphocytes was significantly higher in the chickens kept in floor pens than in those kept in conventional cages (P<0.05). The heterophil-lymphocyte ratio, HSP-90β gene expression level, and DNA damage rate significantly increased in chickens kept in the conventional cages, as compared to the chickens kept in floor pens (P<0.01). In conclusion, there seems to be no difference in the production performance between chickens kept in conventional cages and those kept in floor pens. Furthermore, chickens kept in conventional cages had higher stress response values than those kept in floor pens for all stress response indicators. Therefore, conventional cage types are considered to be a more stressful environment for chickens than floor pens, regardless of the production performance of the chickens.