• Composites Research
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• v.33 no.6
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• pp.371-376
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• 2020

The adhesive strength can be improved through surface treatment. The most common method is to improve physical bonding by varying the surface conditions. This study presents the effect of laser surface treatment on the adhesive strength of CFRP. The surface roughness was patterned using a 1064 nm laser. The effects of the number of laser shots and the direction and length of the pattern on the adhesion of the CFRP/CFRP single joint were investigated through tensile tests. Tests according to ASTM D5868 were performed, and the bonding mechanism was determined by analyzing the damaged surface after a fracture. The optimized number of the laser shots and the optimized depth of the roughness should be required to increase the bonding strength on the CFRP surface. When considering the shear stress in the tensile direction, the roughness pattern in the direction of 45° that increases the length of the fracture path in the adhesive layer resulted in an increase of the adhesive strength. The surface treatment of the bonding surface using a laser is a suitable method to acquire a mechanical bonding mechanism and improve the bonding strength of the CFRP bonding joint. The study on the optimized laser process parameters is required for utilizing the benefits of laser surface processing.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.153-170
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• 2022

Waterjet has been comprehensively used in urban areas owing to a suitable technique for cutting concrete and rock, and low noise and vibration. Recently, the abrasive waterjet technique has been adopted and applied by the Korea Atomic Energy Research Institute to demolish concrete plugging without disturbing and damaging In-situ Demonstration of Engineered Barrier System in the disposal research tunnel. In this study, the use of abrasive waterjet in the tunnel was evaluated for practical applicability and the existing cutting model was compared with the experimental results. As a variable for waterjet cutting, multi-cutting, water flow rate, abrasive flow rate, and standoff distance were selected for the diversity of analysis. As regarding the practical application, the waterjet facilitated path selection for cutting the concrete plugging and prevented additional disturbances in the periphery. The pump's noise at idling was 64.9 dB which is satisfied with the noise regulatory standard, but it exceeded the standard at ejection to air and target concrete because the experiment was performed in the tunnel space. The experimental result showed that the error between the predicted and measured cutting volume was 12~13% for the first cut and 16% for second cut. The standoff distance had a significant influence on the cutting depth and width, and the error tended to decrease with decrement of standoff distance.

• Journal of the Korean Geotechnical Society
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• v.23 no.3
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• pp.25-40
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• 2007

Excessive earth pressure is one of the major mechanical factors in the deformation and damage of Cut-and-Cover Tunnel lining in shallow tunnels and portals of mountain tunnels (Kim, 2000). Excessive earth pressure may be attributed to insufficient compaction and consolidation of backfill material due to self-weight, precipitation and vibration caused by traffic (Komiya et al., 2000; Taylor et al., 1984; Yoo, 1997). Even though there were a lot of tests performed to determine the earth pressure acting on the tunnel lining, unfortunately there were almost no case histories of studies performed to determine remedial measures that reduce differential settlement and excessive earth pressure. In this study the installation of geotextile mat was selected to reduce the differential settlement and excessive earth pressure acting on the cut-and-cover tunnel lining. In order to determine settlement and earth pressure reduction effect (reinforcement effect) of geotextile mat reinforcement, laboratory tunnel model tests were performed. This study was limited to the modeling of rigid circular cut-and-cover tunnel constructed at a depth of $1.0D\sim1.5D$ in loose sandy ground and subjected to a vibration frequency of 100 Hz. Model tests with varying soil cover, mat reinforcement scheme and slope roughness were performed to determine the most effective mat reinforcement scheme. Slope roughness was adjusted by attaching sandpaper #100, #400 and acetate on the cut slope surface. Mat reinforcement effect of each mat reinforcement scheme were presented by the comparison of earth pressure obtained from the unreinforced and mat reinforced model tests. Soil settlement reduction was analyzed and presented using the Picture Analysis Method (Park, 2003).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.175-185
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• 2000

This paper described on a basic study to organize fishing vessel control system in order to control efficiently fishing vessel in Korean offshore. It was digitalized ARPA image on the fishing processing of a fleet of purse seiner in conducting fishing operation at Cheju offshore in Korea as a digital camera and then simulated by used VTMS. Futhermore, it was investigated on the application of FVTMS which can control efficiently fishing vessels in fishing ground. The results obtained were as follows ; (1) It was taken 16 minutes and 35 minutes to casting and hauling net in fishing processing respectively. The length of rope pulled by scout boat was 200m, tactical diameter in casting net was 340.8m, turning speed was 6kts as well. (2) The processing of casting and hauling net was moved to SW, NE as results of simulation when the current direction and speed set into NE, 2kts and SW, 2kts respectively. Such as these results suggest that can predict to control the fishing vessel previously with information of fishing ground, fishery and ship's maneuvering, etc. (3) The control range of VTMS radar used in simulation was about 16 miles. Although converting from a radar of the control vessel to another one, it was continuously acquired for the vector and the target data. The optimum control position could be determined by measuring and analyzing to distance and direction between the control vessel and the fleet of fishing vessel. (4) The FVTMS(fishing vessel traffic management services) model was suggested that fishing vessels received fishing conditions and safety navigation information can operate safely and efficiently.

• Journal of the Korean Vacuum Society
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• v.22 no.5
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• pp.238-244
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• 2013

Doping process using laser is an important process in fabrication of solar cell for heat treatment. However, the process of using the furnace is difficult to form a selective emitter doping region. The case of using a selective emitter laser doping is required an expensive laser equipment and induce the wafer's structure damage due to high temperature. This study, we fabricated a new costly plasma source. Through this, we research the selective emitter doping. We fabricated that the atmospheric pressure plasma jet injected Ar gas is inputted a low frequency (a few tens kHz). We used shallow doping wafers existing PSG (Phosphorus Silicate Glass) on the shallow doping CZ P-type wafer. Atmospheric plasma treatment time was 15 s and 30 s, and current for making the plasma is 40 mA and 70 mA. We investigated a doping profile by using SIMS (Secondary Ion Mass Spectroscopy) and we grasp the sheet resistance of electrical character by using doping profile. As result of experiment, prolonged doping process time and highly plasma current occur a deeper doping depth, moreover improve sheet resistance. We grasped the wafer's surface damage after atmospheric pressure plasma doping by using SEM (Scanning Electron Microscopy). We check that wafer's surface is not changed after plasma doping and atmospheric pressure doping width is broaden by increase of plasma treatment time and current.

• Progress in Medical Physics
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• v.21 no.1
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• pp.86-92
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• 2010

The purpose of this study was to measure curvature contour skin dose using radiochromic film and TLD for a conventional open field. We also attempted to quantify the degradation of skin sparing associated with use of immobilization devices for high energy photon beams and to calculate the skin dose with a help of Monte Carlo (MC) simulation. To simulate head-and-neck and shoulder treatment, a cylindrical solid water phantom 11 cm in diameter was irradiated with 6 MV x-rays using $40{\times}40\;cm^2$ field at 100 cm source axis distance (SAD) to the center of the phantom. Aquaplastic mesh mask was placed on the surface of the cylindrical phantom that mimicked relevant clinical situations. The skin dose profile was obtained by taking measurements from $0^{\circ}$ to $360^{\circ}$ around the circumference of the cylindrical phantom. The skin doses obtained from radiochromic film were found to be 47% of the maximum dose of $D_{max}$ at the $0^{\circ}$ beam entry position and 61% at the $90^{\circ}$ oblique beam position without the mask. Using the mask (1.5 mm), the skin dose received was 59% at $0^{\circ}$ incidence and 78% at $80^{\circ}$ incidence. Skin dose results were also gathered using thin thermoluminescent dosimeters (TLD). With the mask, the skin dose was 66% at $0^{\circ}$ incidence and 80% at $80^{\circ}$ incidence. This method with the mask revealed the similar pattern as film measurement. For the treatments of the head-and-neck and shoulder regions in which immobilization mask was used, skin doses at around tangential angle were nearly the same as the prescription dose. When a sloping skin contour is encountered, skin doses may be abated using thinner and more perforated immoblization devices which should still maintain immoblization.

• Journal of Haehwa Medicine
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• v.4 no.2
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• pp.255-272
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• 1996

소적백출산(消積白朮散)은 ${\ll}$화제국방(和劑局方)${\gg}$에 삼령백출산(蔘笭白朮散)에 정열해독약(淸熱解毒藥)인 와송(瓦松) 금은화(金銀花) 포공영(蒲公英)을 가미(加味)한 처방(處方)으로, 본방(本方)인 삼령백출산(蔘笭白朮散)은 비위허약(脾胃虛弱), 음식부진(飮食不振), 다곤소력(多困少力) 중만비대(中滿痺臺), 심정기천(心柾氣喘), 구토(嘔吐), 설사(泄瀉), 상한해수(傷寒咳嗽)를 치료목적(治療目的)으로 쓰여 온 이래(以來) 임상에서는 대편부실(大便不實), 구설(久泄), 옹달궤후(癰疸潰後) 불사식자(不思食者)를 치료(治療)하는데 다용(多用)되어 왔다. 종양(腫瘍)(Neoplasia)은 새로운 성장(成長)(New+ Glowth) 이라는 세포학적(細胞學的)으로 비정상세포(非正常細胞)의 과다증식(過多增殖)으로 인해 실질장기(實質臟器), 유강장기(有腔腸器), 및 골격(骨格), 피부조직(皮膚組織)에 비정상조직(非正常組織)을 형성(形成)하는 질환(疾患)이다. 현대적(現代的) 종양(腫瘍)과 유사(類似)한 한의학적(韓醫學的)인 병증(病症)은 ${\ll}$소문(素問)${\gg}$에서는 "궐산(厥疝), 복량(伏梁), 식적(息積)"으로 ${\ll}$영추(靈樞)${\gg}$에서는 "장담(腸覃), 석가"로 표시(表示)된 이후(以後)로 소원방(巢元方)은 징가, 식일, 석옹(石癰), 완저(緩疽), 석저(石疽) 등으로 표현(表現)하였다. 원인(原因)에 대(對)해서는 ${\ll}$내경(內經)${\gg}$에서는 허(虛)와 한기(寒氣), 한(寒) 열(熱)로 보았고, 그 외(外)의 학자(學者)들은 내허(內虛)와 기혈불순(氣血不順), 화(火), 한(寒), 기울(氣鬱), 음양불화(陰陽不和)등으로 보았다. 치료(治療)는 ${\ll}$내경(內經) 자법론(刺法論)${\gg}$에서 "정기재내(正氣在內) 사불가우(邪不可于)" 이라 하여 생명활동(生命活動)의 원동력(原動力)인 정기(正氣)의 역할(役割)을 강조(强調)하였고, ${\ll}$육원정기대론(六元正氣大論)${\gg}$에서는 "대적대취(大積大聚) 불가범야(不可犯也) 쇠기태반이지(衰其太半而止)"라 하여 공벌약(攻伐藥)을 과용(過用)하여 정기(正氣)를 손상(損傷)시켜서는 안된다고 하는 등 부정위주(扶正爲主), 거사위주(祛邪爲主) 혹은 부정거사(扶正祛邪) 겸용(兼用)의 방법(方法)이 혼용(混用)되고 있다. 현대(現代) 서양의학(西洋醫學)의 항암제(抗癌劑)는 치료효과(治療效果)는 우수(優秀)하지만 악심(惡心), 구토(嘔吐)를 비롯하여 골수억제효과(骨髓抑制效果)와 간(肝), 심(心), 신(腎), 폐(肺)의 손상(損傷)을 초래(招來)하는 등(等)의 부작용(副作用)을 나타내며, 빈번(頻繁)한 화학요법제(化學療法劑)의 투여(投與)로 인(因)한 암세포(癌細胞)의 약제저항성(藥劑抵抗性) 출현(出現)등이 항암제(抗癌劑)의 문제점(問題點)으로 제시(提示)되고 있다. 이에 저자(著者)는 비위기능(脾胃機能)을 강화(强化)시켜 정기형성(正氣形成)에 깊이 관여(關與)하는 삼령백출산(蔘笭白朮散)에 청열해독(淸熱解毒), 소종산결지제(消腫散結之劑)인 금은화(金銀花), 포공영(浦公英), 와송(瓦松)을 가미(加味)하여 암발생(癌發生) 백서(白鼠)에 투약(投藥)한 후(後) sarcoma 180암세포(癌細胞)에 대(對)한 생명연장효과(生命延長效果)와 항암제(劑)의 일종(一種)인 cis-platin을 이용(利用)하여 양방항암제(洋方抗癌劑)의 부작용(副作用)에 대(對)한 본(本) 방(方)의 효과(效果)를 실험(實驗)하여 관찰(觀察)하였던 바 다음과 같은 결론(結論)을 얻었다. 1. 소적백출산(消積白朮散)은 sarcoma 180 암세포(癌細胞) 이식종양(移植腫瘍)에 대(對)해 생명연장효과(生命延長效果)가 인정(認定)되었다. 2. 소적백출산(消積白朮散)은 치암제(治癌劑)인 cis-platin 치사독성(致死毒性)에 대(對)해 생존연장효과(生存延長效果)가 인정(認定)되었다. 3. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 생쥐 및 흰쥐에 있어서 유의성(有意性) 있는 체중감소억제효과(體重減少抑制效果) 및 serum BUN 상승억제효과(上昇抑制效果)가 인정(認定)되었다. 4. 소적백출산(消積白朮散)은 cis-platin 현독성(賢毒性) 흰쥐에 대(對)해 유의성(有意性) 있는 serum creatinine 상승억제효과(上昇抑制效果)가 나타났으며, cis-platin의 혈액학적(血液學的) 부작용(副作用)인 RBC, WBC 감소(減少)에 대(對)해 감소억제효과(減少抑制效果)가 인정(認定)되었다. 5. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 흰쥐에 대(對)해 뇨량감소억제(尿量減少抑制) 효과(效果) 및 ureanitrogen과 creatinine 배수감소억제효과가 관찰(觀察)되었다. 이상(以上)의 결과(結果)로부터 소적백출산(消積白朮散)은 악성종양치료(惡性腫瘍治療) 및 항암제(劑)의 부작용(副作用)을 경감(輕減)시키는 데 응용(應用)할 수 있을 것으로 사료(思料)된다.

• Food Science and Preservation
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• v.21 no.2
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• pp.264-275
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• 2014

This study evaluated the improving efficacy of Lespedeza cuneata ethanol extract on skin photoaging induced by ultraviolet (UV) irradiation. The total polyphenol and flavonoid contents of the extract were respectively $134.98{\pm}1.70$ and $16.20{\pm}0.05$ mg/g, respectively. The superoxide anion radical scavenging activity and electron-donating ability of the extract were shown to be dependent on concentration, and the antioxidant ability was shown to be more effective in superoxide anion radical scavenging activity than in electron-donating ability under the same concentration conditions. In the in vivo test conducted using hairless mouse with skin photoaging induced by UVB irradiation, the skin erythema of the groups treated with the extract (AS) reduced to 28% of the control, and the skin moisture content increased to 131%.. The extract treatment of the UV-damaged skin improved the morphological and histopathological state of the skin. Furthermore, the SOD, GST and CAT activities in the skin tissue of the AS group increased, and the XO activity and TBARS generation decreased. With regard to the genes related to the photoaging skin, the expression of PAK, p38, c-Fos, c-Jun, TNF-${\alpha}$ and MMP-3 in the skin of the AS group were found to have decreased. It was therefore concluded that Lespedeza cuneata ethanol extract can reduce wrinkle formation in the skin due to the regulation of the gene expression caused by the exposure to UVB light.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.4-23
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• 2013

Songsalli Ancient Tombs of Gongju consists of seven tombs. King Muryeong's tomb, the seventh tomb, is a brick chamber tomb discovered during the drainage works for the fifth and the sixth tombs in 1971. The excavation at the time focused on topographic surveys of the tomb entrance and the inside of the burial chamber as well as collection of the remains. The burial mount survey confirmed the status of some stone slab remaining and lime-mixed soil layers, but the survey did not examine the exterior structure of the whole tomb as the mounds were removed even more deeply. The excavation revealed damages to the bricks and mural damages due to moisture and fungus in the sixth and the seventh tombs. Between 1996 and 1997, Gongju National University conducted a comprehensive detailed survey of Songsalli Ancient Tombs including a geophysical survey, with an aim to identify the root causes of such degradation. Based on the results, repair took place in 1999 and the fifth, sixth and seventh tombs were placed under permanent conservation to conserve the cultural assets. General public is currently denied access. The purpose of this study was to conduct a three-dimensional resistivity and GPR surveys on the ground surface of the fifth, sixth and seventh tombs of Songsalli Ancient Tombs in order to understand the underground status after repair. The study also aimed to understand the thickness of all the tomb walls and exterior structure based on GPR inside King Muryeong's tomb. The exploration on the ground surface found that the three tombs and soil adjacent to the tombs had resistivity as low as 5 to $90{\Omega}m$, which confirmed that the soil water content was still as high as that prior to the repair work. Additionally, GPR found that the wall construction of the burial chamber of King Muryeong's tomb was approximately 70cm in thickness, while the structure was of 2B with two bricks, about 35cm in length, put together longitudinally(2B brick masonry). The pathway to the burial chamber was of the 2B structure just like that of the burial chamber walls, while its thickness was 80cm with an eyebrow-type arch connected to it. Also, the ceiling exterior appears to have an arch structure, identical to the shape inside.

• Advances in pediatric surgery
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• v.8 no.2
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• pp.143-155
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• 2002

A survey on biliary atresia was made among 26 members of the Korean Association of Pediatric Surgeons. The members were required to complete a questionnaire and a case registration form for each patient during the twentyone-year period of 1980-2000. Three hundred and eighty patients were registered from 18 institutions. The average number of patients per surgeon was one to two every year. The male to female ratio was 1:1.3. The age of patients on diagnosis with biliary atresia was on average $65.4{\pm} 36.2$ days old. The national distribution was 32.8% in Seoul, 25.3% in Gyoungki-Do, 21.6% in Gyoungsang-Do, 9.27% in Choongchung-Do, etc. in order. The most common clinical presentation was jaundice (98.4%) and change of stool color (86.2%) was second. Two hundred eighty (74.7%) of 375 patients were operated by 80 days of age. Three hundred thirty six (9 1.9%) of 366 patients were operated on by the original Kasai procedure, and 305 (84.3%) of 362 patients were observed by bile-drainage postoperatively. The overall postoperative complication rate was 18.5% and the overall postoperative mortality rate was 6.8%. The associated anomalies were observed in 72 cases (22.5%). One hundred ninty five (64.7%) of 302 patients have been alive in follow-up and 49 (25.1%) have survived over 5 years without problem after operation. Ascending cholangitis, varices and ascites affected survival significantly, and the important long-term prognostic factor was the occurrence of complications.