• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.16-20
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• 2005

Tricholoma matsutake ectomycorrhizas are unique in their morphology: not bifurcated broom shaped roots with not easily wettable brilliant and profuse white hyphae. To understand these characteristics the ectomycorrhizas were investigated with electron microscopy. T. matsutake ectomycorrhiza have thin mantle and typical Hartig net development in the epidermis and cortex, but no fungal mantle on the root apex. There were no penetrating hyphae inside of the cells of either epidermis, cortex or stele. Inside of the walls of epidermis and cortex cells are lined with ca. $2{\mu}m$ hemispherical amyloplasts. The brilliant hyphal surface was covered with various fine amorphous granules. The hyphal cell wall was thin membrane less than $0.3{\mu}m$ thick. There is no clamp connection on the hyphae. This thin membraneous cell wall with high elasticity can be related to survival strategy of the species without plasmolysis under frequent soil water stress environment. And the coarse hyphal surface with some water repellency can control sudden inrush of water of the hyphae with an extremely low osmotic potential. It is concluded that no mantle on the tip can induce mycorrhizas not bifurcated and that finely coarse surface of T. matsutake hyphae can make the hyphae brilliantly white but less wetted.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.07a
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• pp.25-37
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• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Journal of Conservation Science
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• v.24
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• pp.1-11
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• 2008

The Unhyungung Water Container in the possession of the Seoul Museum of History in Korea is consisted of a calcareous marble developed laminated bedding and numerous argillaceous veinlets. This monument should need to conservation treatment because of black discoloration and seriously numerous cracks. Vertical and horizontal cracks in the monument are developed following stratification and argillaceous veinlets that are relatively low coherence between the rock materials. We have proved that the material inducing discoloration on the surface is carbon which is formed by deposited organic matters. As the result of the ultrasonic measurements, although highly surface weathering degree, the physical properties of the Unhyungung Water Container is confirmed slightly weathered state. The depths of cracks in the monument are calculated at maximum 60mm in some cracks completely penetrating into the wall and at minimum 9mm in the other crack. The cracks, developed following veinlet, are revealed that there penetrate from an outer wall to an inside wall for the monument. And most depths of cracks, developed following stratification, are calculated 20 to 30mm. This result will offer a significant data for conservation of the Unhyungung Water Container.

• Design & Manufacturing
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• v.13 no.4
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• pp.10-16
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• 2019

Semiconductor chip is bonded to the substrate by melting solder bumps. In general, the chip bonding is applied by a Reflow process or a Thermo-Compression(TC) bonding process. In this paper, we introduce a Laser Assisted Thermo-Compression bonding (LATCB) process to improve the anxiety of the existing process(Reflow, TC bonding). In the LATCB process, the chip is bonded to the substrate by irradiating a laser with a uniform energy density in the same area as the chip to melt only the solder bumps and press the chip with a Transparent Compression Module (TCM). The TCM consists of a fused silica header for penetrating the laser and pressurizing the chip, and a piezoelectric actuator (P.A.) coupled to both ends of the header for micro displacement control of the header. In addition, TCM is a structure that can pressurize the chip and deliver it to the chip and solder bumps without losing the energy of the laser. Fused silica, which is brittle, is vulnerable to deformation, so the header may be damaged when an external force is applied for pressurization or a displacement differenced is caused by piezoelectric actuators at both ends. On the other hand, in order to avoid interference between the header and the adjacent chip when pressing the chip using the TCM, the header has a notch at the bottom, and breakage due to stress concentration of the notch is expected. In this study, the thickness and notch length that the header does not break when the external force (500 N) is applied to both ends of the header are optimized using structural analysis and Coulomb-Mohr failure theory. In addition, the maximum displacement difference of the P.A.s at both ends where no break occurred in the header was derived. As a result, the thickness of the header is 11 mm, and the maximum displacement difference between both ends is 8 um.

• Cartoon and Animation Studies
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• s.45
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• pp.215-233
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• 2016

Timelapse which was appeared Georges Mellieoseu in 1897 was not familiar to people and was not popular in film or broadcast industry in spite of long history. But about 5 years ago, timelapse has become distinguished in all around image art, because it show us aesthetic extraction of time and variation of color in Vimeo and Youtube which neve been seen before. So nowadays latest camera has come out with default menu which can shoot timelapse. But popularity of timelapse seem not development of cinematography technique or appearance of new function but production of image which reflects ages of present with fully accept digital media property. This study is approached from two formative characteristics. First it is strengthen of time which is showed timelapse and analog media from a comparison angle. Second, it is how to extend their sense and imitate images through resolution which can be possible high quality image and color especially with Raw data Through these methodology, this study defines correlation of character of digital media and artistic value of images in timelapse. And also it cleary assures the era of penetrating art has not only visual amusement as known but, also representative value of our ages and technology of media.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.525-534
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• 2014

Environmental problems typically occurring in abandoned mine lands (AML) include: contaminated and acidic surface water and groundwater; stockpiled waste rock and mill tailings; and ground subsidences due to mining operations. This study examines the effectiveness of various geophysical techniques for mapping potential hazard and contaminated zones. Four AML sites with sedimentation contamination problems, acid mine drainage (AMD) channels, ground subsidence, manmade liner leakage, and buried mine tailings, were selected to examine the applicability of various geophysical methods to the identification of the different types of mine hazards. Geophysical results were correlated to borehole data (core samples, well logs, tomographic profiles, etc.) and water sample data (pH, electrical conductivity (EC), and heavy metal contents). Zones of low electrical resistivity (ER) corresponded to areas contaminated by heavy metals, especially contamination by Cu, Pb, and Zn. The main pathways of AMD leachate were successfully mapped using ER methods (low anomaly peaks), self-potential (SP) curves (negative peaks), and ground penetrating radar (GPR) at shallow penetration depths. Mine cavities were well located based on composite interpretations of ER, seismic tomography, and well-log records; mine cavity locations were also observed in drill core data and using borehole image processing systems (BIPS). Damaged zones in buried manmade liners (used to block descending leachate) were precisely detected by ER mapping, and buried rock waste and tailings piles were characterized by low-velocity zones in seismic refraction data and high-resistivity zones in the ER data.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.217-222
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• 2012

Purpose: Diaphragmatic rupture following trauma is often an associated and missed injury. This report is about our experience with treating traumatic diaphragmatic rupture (TDR). Methods: From January 2007 to September 2012, 18 patients who had a diaphragmatic rupture due to blunt trauma or penetrating injury underwent an operation for diaphragmatic rupture at our hospital. We retrospectively reviewed their medical records, including demographic factors, initial vital signs, associated injuries, interval between trauma and diagnosis, injured side of the diaphragm, diagnostic tools, surgical method or approaches, operative time, herniated organs, complications, and mortality. Results: The average age of the patients was 43 years, and 16 patients were male. Causes of trauma included motor vehicle crashes (n=7), falls (n=7), and stab wounds (n=5). The TDR was right-sided in 6 patients and left-sided in 12. The diagnosis was made by using a chest X-ray (n=3), and thorax or upper abdominal computed tomography (n=15). Ten(10) patients were diagnosed within 12 hours. A thoracotomy was performed in 8 patients, a video-assisted thoracoscopic surgery in 4 patients, a laparotomy in 3 patients, and a sternotomy in one patient. Herniated organs were the omentum (n=11), stomach (n=8), spleen and colon (n=6), and liver (n=6). Eighteen diaphragmatic injuries were repaired primarily. Seven patients underwent ventilator care, and two of them had pneumonia and acute respiratory distress syndrome. There were no operative mortalities. Conclusion: Early diagnosis and surgical treatment determine the successful management of TDR with or without the herniation of abdominal organs. The surgical approach to TDR is chosen based on accompanying organ injuries and the injured side.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.115-121
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• 2012

Purpose: Severe pancreaticoduodenal injuries are relatively uncommon, but may result in high morbidity and mortality, especially when management is not optimal, and determining the appropriate treatment is often difficult. The objective of this study was to review our experience and to evaluate the role of a pancreaticoduodenectomy (PD) in treatment of pancreaticoduodenal injuries. Methods: We performed a retrospective review of 16 patients who underwent an emergency PD at our hospital for severe pancreaticoduodenal injury from 1990 to 2011. Demographic data, clinical manifestations, mechanism and severity of the injury, associated injuries, postoperative complications and outcomes were reviewed. Results: The mean age of the 16 patients was $45{\pm}12years$ ($mean{\pm}standard$ deviation), and 15(93.8%) patients were male. All patients underwent an explorative laparotomy after a diagnosis using abdominal computed tomography. Almost all patients were classified as AAST grade higher than III. Thirteen(83.3%) of the 16 patients presented with blunt injuries; none presented with a penetrating injury. Only one(6.3%) patients had a combined major vascular injury. Fifteen patients underwent a standard Whipple's operation, and 1 patient underwent a pylorus-preserving pancreaticoduodenectomy. Two of the 16 patients required an initial damage-control procedure; then, a PD was performed. The most common associated injured organs were the small bowel mesentery(12, 75%) and the liver(7, 43.8%). Complications were intraabdominal abscess(50%), delayed gastric emptying(37.5%), postoperative pancreatic fistula(31.5%), and postoperative hemorrhage (12.5%). No mortalities occurred after the PD. Conclusion: Although the postoperative morbidity rate is relatively higher, an emergency PD can be perform safely without mortality for severe pancreaticoduodenal injuries. Therefore, an emergency PD should be considered as a life-saving procedure applicable to patients with unreconstructable pancreaticoduodenal injuries, provided that is performed by an experienced hepatobiliary surgeon and the patient is hemodynamically stable.

• Journal of Trauma and Injury
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• v.22 no.1
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• pp.5-11
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• 2009

Purpose: The mortality and the amputation rates due to vascular trauma remain high despite advanced vascular surgical techniques and supportive management. The clinical features of patients with vascular trauma have not been well studied in the Korean population. The aim of this study was to analyze the clinical characteristics of patients with vascular trauma and to develop a database and guidelines for improving the outcomes of treatment. Methods: The medical records of 37 patients with traumatic vascular injuries who had visited in an emergency center between January 2002 and December 2006 were retrospectively reviewed and statistically analyzed. Results: The mean age was 37.8 years, and the male-to-female ratio was 5.2 : 1. The mechanism of vascular trauma was penetrating in 18 patients and blunt in 19 patients. Upper extremities were most frequently injured (39.4%). The treatment methods were primary repair in 21 patients, exploratory laparotomies in 7, radiological interventions in 3, resections and graft interpositions of the pseudoaneurysm in 3, observations in 3 and a bypass graft in 1. Four out of the 37 patients died, and three of these who died had injuried abdominal vessels. Twenty-five of the patients recovered completely, four expired, seven had neuropathy in the course of treatement, one had his limb amputated, and one experienced wound necrosis. Conclusion: Peripheral vessel injuries are commonly accompanied by nerve, muscle, or tendon injuries. Patients without associated fractures or compartment syndrome had good prognosis. Although the time intervals from hospital arrival to definite treatment were the shortest among patients with blunt abdominal vascular injuries, three expired. Therefore, we offer a 'ritical pathway'to improve the outcomes of patients with blunt abdominal vascular injury.

• Journal of Chest Surgery
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• v.43 no.1
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• pp.47-52
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• 2010

Background: Traumatic diaphragmatic rupture is not common, but it requires swiftly performing an emergency operation. This study was conducted to evaluate the prognostic factors for mortality after surgically treating traumatic diaphragmatic rupture. Material and Method: From Jan 2001 to Dec. 2008, we experienced 37 cases of multiple traumas with diaphragmatic injuries that were confirmed by surgical procedures. We evaluated various factors, including the type of injury, the associated injuries, the preoperative vital signs, the ISS, the time until surgery and the rupture size. Result: There were 30 patients with blunt trauma and 7 patients with penetrating trauma. Thirty-four patients had associated injuries and the mean ISS was 20.8. Postoperative complications occurred in 11 patients and hospital mortalities occurred in 6 patients. The prognostic factors that had an influence on the postoperative mortalities were the preoperative intubation state, the patient who exhibited hypotension and a high ISS. Conclusion: Traumatic diaphragmatic rupture is just one part of multiple traumas. The postoperative mortalities might depend on not only on the diaphragmatic rupture itself, but also on the severity of the associated injuries.