• Journal of the Korean Magnetics Society
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• v.25 no.3
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• pp.67-73
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• 2015

This is a basic research for improving soft magnetic property of Fe based nano crystalline alloy powder core. The main study is done around characteristics of permeability, core loss, and DC bias depending on amount of insulation coating agent and particle size. First, $Fe_{73.5}Si_{13.5}B_9Nb_3Cu_1$ amorphous alloy ribbon was fabricated by using the planar flow casting (PFC) device. Then, heat treatment and ball milling were done to obtain alloy powder. The amount of polyether imide (PEI) added to it was varied by 0.5, 1.0, 2.0, 2.5 wt% to have compression molding into $16ton/cm^2$. After going through crystalline heat treatment, the made toroidal nano crystalline powder core ($OD12.7mm^*ID7.62mm^*H4.75mm$) had smaller permeability as amount of insulation coating agent decreases. However, it was found out that core loss and DC bias characteristics have been improved. The reason for this results were expected to be because green density of power core decreases as amorphous alloy powder particles become smaller as amount of alloy powder insulation coating agent increases, it was determined that 1 wt% of insulation coating agent is appropriate. Also, for powder core made based on alloy powder size with amount of insulation coating agent fixed at 1 wt%, effective permeability and core loss were outstanding as particle size became bigger. However, characteristics of DC bias became worse as applied DC field increases. This is expected to be due to insulation effect, residual pores, or molding density of powder core resulting from thickness of coating on surface of alloy powder.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.81-93
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• 1990

The author fractographically analyized the cause of metal failure(the first time this procedure has been used for this metal failure)and also analyized it clinically. In this study, I selected eight cases which have been analyized fractographically. In all these cases, the analysis was done after treatment of metal failure of implants internally fixed to femur shaft fractures at the Department of Orthopedic Surgery, Yeung-Nam University Hospital during the six year period from May 1983 to September 1989. 1. Metal failure occured in five dynamic-compression plates, one Jewett nail, one screw in Rowe plate, and one interlocking nail. 2. The clinical cause of metal failure was deficiency of medial butress in five cases, incorrect position of implant in one case, and incorrect selection of implant in two cases. 3. The time interval between internal fixation and metal failure was four months in one case, between five months to twelve months in six cases, three years in one case. 4. The fractographically analytical cause of metal failure was ; first, impact failure, one case, second, fatigue failure, six cases, machining mark(stress liser), four cases type : low consistent cyclic fatigue failure irregular cyclic fatigue failure third, stress corrosion crack, one case. 5. 316L Stainless Steel has good resistance to corrosion. However, when its peculiar surface film is destroyed by fretting, it shows pitting corrosion. This is, perhaps, the main cause of metal failure. 6. It is possible that mechanical injury occured in implants during the manufacturing of implants or that making a screw hole is the main cause of metal failure.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.49-61
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• 2014

Purpose: With the aging of the population, the attack rate of osteoporotic vertebral compression fracture is in the increasing trend, and percutaneous vertebroplasty (PVP) is the most commonly performed standardized treatment. Although there is a research report of the excellence of usefulness of the SPECT/CT examination in terns of the exact diagnosis before and after the procedure, the bone cement material used in the procedure influences the image quality by forming an artifact in the CT image. Therefore, the objective of the research lies on evaluating the effect the bone cement gives to a SPECT/CT image. Materials and Methods: The images were acquired by inserting a model cement to each cylinder, after setting the background (3.6 kBq/mL), hot cylinder (29.6 kBq/mL) and cold cylinder (water) to the NEMA-1994 phantom. It was reconstructed with Astonish (Iterative: 4 Subset: 16), and non attenuation correction (NAC), attenuation correction (AC+SC-) and attenuation and scatter correction (AC+SC+) were used for the CT correction method. The mean count by each correction method and the count change ratio by the existence of the cement material were compared and the contrast recovery coefficient (CRC) was obtained. Additionally, the bone/soft tissue ratio (B/S ratio) was obtained after measuring the mean count of the 4 places including the soft tissue(spine erector muscle) after dividing the vertebral body into fracture region, normal region and cement by selecting the 20 patients those have performed PVP from the 107 patients diagnosed of compression fracture. Results: The mean count by the existence of a cement material showed the rate of increase of 12.4%, 6.5%, 1.5% at the hot cylinder of the phantom by NAC, AC+SC- and AC+SC+ when cement existed, 75.2%, 85.4%, 102.9% at the cold cylinder, 13.6%, 18.2%, 9.1% at the background, 33.1%, 41.4%, 63.5% at the fracture region of the clinical image, 53.1%, 61.6%, 67.7% at the normal region and 10.0%, 4.7%, 3.6% at the soft tissue. Meanwhile, a relative count reduction could be verified at the cement adjacent part at the inside of the cylinder, and the phantom image on the lesion and the count increase ratio of the clinical image showed a contrary phase. CRC implying the contrast ratio and B/S ratio was improved in the order of NAC, AC+SC-, AC+SC+, and was constant without a big change in the cold cylinder of the phantom. AC+SC- for the quantitative count, and AC+SC+ for the contrast ratio was analyzed to be the highest. Conclusion: It is considered to be useful in a clinical diagnosis if the application of AC+SC+ that improves the contrast ratio is combined, as it increases the noise count of the soft tissue and the scatter region as well along with the effect of the bone cement in contrast to the fact that the use of AC+SC- in the spine SPECT/CT examination of a PVP performed patient drastically increases the image count and enables a high density of image of the lesion(fracture).

• Clinics in Shoulder and Elbow
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• v.16 no.1
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• pp.17-26
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• 2013

Purpose: A comparison of the radiographic and the clinical outcomes between two different surgical approaches-Deltoid splitting and Delto-pectoral interval-on the proximal humerus fractures treated by locking compressive plate (LCP), is done. Materials and Methods: Medical records and pre- and postoperative radiographs were reviewed retrospectively for 75 adult patients who underwent surgical fixations with locking compressive plates from May 2005 to December 2011. Patients were divided into two groups according to the surgical methods. Differences in the neck-shaft angle between immediate postoperative period and final follow-up were compared between the two groups. Differences in constant score and Korean shoulder score (KSS) between affected arms and contralateral arms at final follow-up were also compared. Results: The differences in the neck-shaft angle between immediate postoperative period and at final follow-up was 12.04 degrees on average in Deltoid splitting approach and 10.20 degrees in Delto-pectoral interval approach, which was not statistically significant. Differences in constant score/KSS between the affected arm and the contralateral arm were 13.78/22.74 points in deltoid-splitting approach on average and 19.41/31.13 points in Delto-pectoral interval approach, showing that deltoid-splitting approach is significantly superior. Conclusion: Deltoid-splitting approach showed better functional outcomes in the fracture reduction and internal fixation using LCP for the treatment of unstable proximal humerus fractures.

• The korean journal of orthodontics
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• v.36 no.2 s.115
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• pp.103-113
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• 2006

Most elderly women experience a decrease in their bone density due to a deficiency of calcium intake, ovariectomy, or menopause. This study evaluated the usability of the microscrew as a skeletal anchorage system in these orthodontic treatment cases, using rats as a research group. The 4 month old sprague-dawley species rats were divided into two groups, the OS (Ovariectomy Screw), and the SS (Sham operation Screw) group. In both the OS and SS groups, microscrews were implanted into the palatal bone between the upper molar teeth and two upper incisors were retracted using NETE coil spring with 75 g of force. After 3days, the again after 7 days, 7 rats in each group were sacrificed. Three days before they were sacrificed, Alizarin red S was intraperitoneally injected, and their maxillary bone, tibia and blood from their hearts were taken. The components of the extracted blood were biochemically analyzed and non-decalcified grinding resin sections for maxillary bone and tibia were made. The sections were examined with a polarization microscope, and fluorescent microscope. Smaller concentrations of Ca and P, the inorganic substances closely related to bone density, were found in the extracted blood of the OS group. Both OS and SS groups showed a possibility of bone remodeling with a high concentration of ALP after 7 days. An increase in bone density on the tension and compression sides of the microscrew and the tension side of the tooth for both OS and SS groups was confirmed with a polarization microscope. However, the bone density of the pressure side of the tooth and apical side was decreased. More deposits of Alizarin red S in the bone after 7 days rather than 3 days seen with a fluorescent microscope suggested the existence of new bone formation.

• Clinical and Experimental Pediatrics
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• v.45 no.9
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• pp.1090-1096
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• 2002

Purpose : We evaluated the clinical manifestations, bronchoscopic findings and therapeutic effects of flexible fiberoptic bronchoscopy in atelectasis of children. Methods : Sixty six children who received bronchoscopy due to persistent atelectasis, acute severe atelectasis and incidental atelectasis on plain chest radiography were studied retrospectively. Results : The most common causative underlying disease was pneumonia(60.4%). Other underlying conditions were pulmonary tuberculosis, chronic lung disease, postoperative state, bronchial asthma and chest trauma. The most common abnormal findings were inflammatory changes such as bronchial stenosis(n=15), mucosal edema and large amount of secretion(n=14), granulation tissue( n=3) and mucus plug(n=3) although 39.4% showed normal airways. Other findings were congenital airway anomalies, endobronchial tuberculosis, extrinsic compression and obstruction by blood clot. In 32 children with pneumonia-associated atelectasis, 43.7% revealed normal airways, and the most common abnormal findings were also inflammatory changes. Eighteen out of 39 patients who received therapeutic intervention such as suctioning of secretion, bronchial washing and intrabronchial administration of N-acetylcysteine($Mucomyst^{(R)}$) had complete or partial resolution of their atelectasis. In 32 patients with pneumonia-associated atelectasis, 56.5% showed improvement by therapeutic intervention. Conclusion : In this study, atelectasis was mainly associated with inflammatory airway diseases such as pneumonia. The most common abnormal bronchoscopic findings were inflammatory changes such as mucosal edema and large amounts of secretion and bronchial stenosis, although about 40% revealed normal airway. Flexible bronchoscopy is helpful for either diagnosis or treatment, especially in pneumonia-associated atelectasis.

• Journal of East-West Nursing Research
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• v.1 no.1
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• pp.50-71
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• 1997

The intention of this study is to apprehend the con. tents and methods of herb remedies that are commonly conducted when there are health-problem cases of ENT, eyes, teeth and skin. Methods of this study are divided into two stages : 1) For a period of six months from December 1994 to June 1995, some 40 persons who are believed to be well versed with herb remedies have been randomly chosen, and we made a survey on herb remedies by symptoms: and 2) we have endeavored to make their grounds evident through the studies on literatures with the focus on the basic data collected. Their results are as follows: 1) When one feels a pain in ears, such herb remedies are employed as pouring the vapor into ears, which is made by steaming Alaska pollack, or as applying or wiping with the juices of radish or the ginkgo, or' alum. Applying the radish juice is effective for sterilization and fever removal: and applying the ginkgo juice is effective for cleanliness. But, plastering alum, sesame oil or castor oil, or pouring the vapor of Alaska pollack into ears are perhaps effective but do not have any pharmacologic grounds. 2) When one bleeds at the nose, such kinds of herb remedies are applied as stimulating nose or head with cold water, pressing nose or ridge of nose, or filling up nares with mashed mugworts. In addition, they have utilized garlic or leeks. Such methods as stimulating with cold water or just pressing nose and ridge of nose is based on reasonable grounds, i.e. vasoconstriction and vascular compression ; and applying mashed garlic on the sole of foot is good for the circulation of Qui ; and the use of mugworts and leeks is based upon the pharmacological function of hemostasis. 3) When one feels a sore throat such kinds of herb remedies are employed as gargling or rinsing throat with brine, drinking hot gruel or water, or drinking the juice of mugwort, radish, ginger or Chinese quince. Gargling with brine or drinking the juice of mugwort, radish or ginger is based upon the pharmacological function of pain alleviation, fever removal, and detoxication. 4) When a boil is formed in mouth, such herb remedies are applied as spreading honey, brine or alum water, and taking gall nut, Chinese matrimony vine, lotus root, etc, for drugs. Spreading honey, brine or water that is made by infusing gallnut, Chinese matrimony vine, lotus root is based upon such functions as hematosis, astriction, antibacterial, and antiphlogistic, Alum, eggplant and licorice are said to be effective, but their pharmacological effects have no grounds. 5) When one has conjunctivitis such herb remedies are commonly applied as irrigation with brine and dropping breast milk in eyes. Moreover, such other drugs are used as plantain. shepherd's purse, and purslane, etc. The use of brine, breast milk, plantain, shepherd's purse and purslane is based upon such functions as sterilization, antiphlogistic, disinfection and pain relieving. Eriocaulon sieboldianum, bean stem, bean pod and narcissus leaves are said to be effective, but their pharmacological action have no basis. When one has a stye, such herb remedies are applied as extracting eyelashes, stimulating by a massage of middle finger, third finger or big toe, as well as sear ing with a heated bamboo comb that is fine-toothed. Other than these, plantain and nightshade's nuts are used as drugs for it. Extracting eyelashes corresponds with exclusing suppurative node and draining the stye of pus ; and the use of plantain is based upon disinfection: and nightshade's nuts are said to be effective, however, their pharmacological action has no grounds. 6) For a treatment of toothache, such herb remedies are commonly employed as rinsing mouth with brine and holding cold water or gasoline in the mouth ; and as the drugs that are believed to be effective have been Welsh onion, ginger and castor-oil, plant, etc. The use of Welsh onion is based upon pain killing, antiinflammatory actions, and the use of ginger is based upon detoxication and disinfection ; and seeds of castor-oil plants are said to be effective, but they have no pharmacological basis. 7) When one has hives, such herb remedies are commonly applied as rubbing burned straw in affected parts, exposing to its smoke, rubbing with salt, sweeping down with a broom, and spreading and drinking boiled water of trifoliate orange. The use of cassia tora seeds, walnut, aloe and radish is said to be effective. The use of cassia tor a seeds has the functions of intestinal order, anti-paralysis, etc. The use of walnut has resulted in an increase of blood by invigorating spirits ; and the use of aloe is based upon disinfection, antibiotic, anti-salt, antihistamine and detoxication action. But, the effects of radish juice and straw's smoke have no pharmacological grounds. 8) When one gets a boil, such herb remedies are commonly used as applying a plaster, paste of flour mixed with yolk, soy sauce or honey, as well as spreading pounded elm tree. Other remedies that have been said to be effective are ; heating with mugwort, brine, wild rocambole, aloe, onion, squid's bone, etc. The use of mugwort is based upon pain killing, astringent antiinflammatory and tranquility. Wild rocambole is based upon the generation and maintenance functions of cell-joining textures ; elm tree upon antiphlogistic ; aloe upon fever removal and antiphlogistic ; onion on pain killing, fever removal, antiphlogistic and tranquility ; squid's bone on astriction: and brine or vinegar on sterilization. Pine resin and gardenia seed are said to be effective, but they have no pharmacological basis. 9) When one cuts his skin, such herb remedies are commonly employed as spreading mugwort's juice or squid's bone powder, or pressing the wounds. In addition, kalopanax, onion and fine soil are employed. The use of mugwort, kalopanax and squid's bone is based upon such functions as hemostasis, sedation, pain killing, antibacterial ; and fine soil is said to be effective, but it has no pharmacological basis. 10) When one suffers from whitlow, such herb remedies are commonly utilized as heating with boiled soy sauce, spreading soybean paste, or dipping into eggs, etc. Other drugs that have been employed are onion root, brine, eggplant, potato, loach, etc. The use of onion is based upon pain killing and antiphlogistic functions ; and that of brine upon antiphlogistic function. The use of soy sauce or soybean paste, fomentation, eggplant, potato and loach is said to be effective, but it has no pharmacblogic ground. 11) For the treatment of frostbite, such herb remedies are commonly used as dipping the affected part into frozen soybean sack, using boiled water of eggplant stem, garlic caulis, onion, hot pepper, caulis. Onion is based upon antiphlogistic and tranquility actions garlic upon disintection, metabolic exacerbation, tonic and aphrodisiac actions and the use of eggplant and hot pepper is based upon help blood circulation, dissolution and excretion of waste matters in vein. 12) For the treatment of burn, such herb remedies or drugs are commonly used as cleansing with Korean gin, spreading eggs, cleansing with cold water and soap water ; and as brine, cactus, moss, soybean paste, oil, etc. The cleansing with Korean gin, cold water, soap water, brine, vinegar is based upon cleaning and sterilizing functions ; and the use of cucumber is based upon nu. trition provision, and strengthening of resisting power by adjustment of metabolism. The use of potato, cactus, moss, oil and eggs is said to be effective, but their phamacological functions are not clarified. In view of the above results, we can realize that the drugs that have been employed in herb remedies are quite diverse. However, in regard to majority of herb remedies that have been employed by symptoms, the pharmacological functions of their drugs have not been clarified, and they are merely known as effective. Furthermore, they have not been recorded in the literature as yet ; and we confirm that there have been many herb remedies that were executed without the proper knowlege of their effects. It is now our view that the results of this survey may be utilized for consulting data in regard to the use of herb remedies.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.737-744
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• 2005

Purpose : Infants and children with cardiovascular diseases often present with respiratory symptoms. However, missed or delayed evaluation for potential airway problem may complicate overall prognosis. The aim of this study is to determine the clinical characteristics of these patients and explore the cause of airway problem. Methods : We reviewed the medical records of 64 patients(M : F=33:31, mean age : $6.3{\pm}7.5$ months) whose airway problems were proven by computed tomography or bronchoscopy in perioperative periods at the Asan Medical Center from January 1997 to June 2004. Patients were divided into two groups based on the duration of ventilator care : ${\leq}7$ days(group 1 : 23 cases, M : F=10 : 13) and >7 days(group 2 : 41 cases, M : F=23 : 18). Results : The patients in group 2 significantly developed more post-operative respiratory symptoms than group 1(P<0.001) and had more airway problems including extrinsic obstruction, intrinsic anomaly, and combined problem than group 1 although not significantly different(P=0.082). Among underlying diseases, the most common diseases were vascular anomaly(26.2 percent) and aortic arch anomaly(26.2 percent) in group 1 and pulmonary atresia with ventricular septal defect(22.4 percent) in group 2. The most frequent respiratory symptoms were recurrent wheezing pre-operatively and failure of ventilator weaning post-operatively. The major types of airway anomaly were tracheomalacia and tracheal stenosis(in each case 18.2 percent). Nineteen patients with persistent airway problems underwent aortopexy or other vascular correction. Of the 19 patients, 13(68.4 percent) were improved, but 2 failed in weaning ventilator and 4 died of non-airway problems. Conclusion : Early evaluation and treatment for potential airway problems may affect natural or surgical prognosis in patients with cardiovascular diseases presenting with respiratory symptoms.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.147-157
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• 2013

With the advent of the digital environment that can be accessed anytime, anywhere with the introduction of high-speed network, the free distribution and use of digital content were made possible. Ironically this environment is raising a variety of copyright infringement, and product images used in the online shopping mall are pirated frequently. There are many controversial issues whether shopping mall images are creative works or not. According to Supreme Court's decision in 2001, to ad pictures taken with ham products is simply a clone of the appearance of objects to deliver nothing but the decision was not only creative expression. But for the photographer's losses recognized in the advertising photo shoot takes the typical cost was estimated damages. According to Seoul District Court precedents in 2003, if there are the photographer's personality and creativity in the selection of the subject, the composition of the set, the direction and amount of light control, set the angle of the camera, shutter speed, shutter chance, other shooting methods for capturing, developing and printing process, the works should be protected by copyright law by the Court's sentence. In order to receive copyright protection of the shopping mall images by the law, it is simply not to convey the status of the product, the photographer's personality and creativity can be recognized that it requires effort. Accordingly, the cost of making the mall image increases, and the necessity for copyright protection becomes higher. The product images of the online shopping mall have a very unique configuration unlike the general pictures such as portraits and landscape photos and, therefore, the general image watermarking technique can not satisfy the requirements of the image watermarking. Because background of product images commonly used in shopping malls is white or black, or gray scale (gradient) color, it is difficult to utilize the space to embed a watermark and the area is very sensitive even a slight change. In this paper, the characteristics of images used in shopping malls are analyzed and a watermarking technology which is suitable to the shopping mall images is proposed. The proposed image watermarking technology divide a product image into smaller blocks, and the corresponding blocks are transformed by DCT (Discrete Cosine Transform), and then the watermark information was inserted into images using quantization of DCT coefficients. Because uniform treatment of the DCT coefficients for quantization cause visual blocking artifacts, the proposed algorithm used weighted mask which quantizes finely the coefficients located block boundaries and coarsely the coefficients located center area of the block. This mask improves subjective visual quality as well as the objective quality of the images. In addition, in order to improve the safety of the algorithm, the blocks which is embedded the watermark are randomly selected and the turbo code is used to reduce the BER when extracting the watermark. The PSNR(Peak Signal to Noise Ratio) of the shopping mall image watermarked by the proposed algorithm is 40.7~48.5[dB] and BER(Bit Error Rate) after JPEG with QF = 70 is 0. This means the watermarked image is high quality and the algorithm is robust to JPEG compression that is used generally at the online shopping malls. Also, for 40% change in size and 40 degrees of rotation, the BER is 0. In general, the shopping malls are used compressed images with QF which is higher than 90. Because the pirated image is used to replicate from original image, the proposed algorithm can identify the copyright infringement in the most cases. As shown the experimental results, the proposed algorithm is suitable to the shopping mall images with simple background. However, the future study should be carried out to enhance the robustness of the proposed algorithm because the robustness loss is occurred after mask process.