• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.552-555
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• 2004

The reliability issue of the probe tip/recording media interface is one of the most crucial concerns in the Atomic Force Microscope (AFM)-based recording technology. In this work, the tribological characteristics of the probe/media interface were investigated by performing wear tests using an AFM. The ranges of applied normal load and sliding velocity for the wear test were 10 to 50nN and 2 to 20$\mu$m/s respectively. The damage of the probe tip was quantitatively as well as qualitatively characterized by Field Emission Scanning Probe Microscope (FESEM) analysis and calculated based on Archard s wear equation. It was shown that the wear coefficient of the probe tip was in the order of 10$^{-4}$ ~ 10$^{-3}$ , and significant contamination at the end of the probe tip was observed. Thus in order to implement the AFM-based recording technology, tribological optimization of the probe/media interface must be achieved.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제17권1호
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• pp.13-22
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• 2014

Esophageal pH monitoring is considered the gold standard for the diagnosis of gastroesophageal reflux disease because of the normal ranges across the pediatric age range. However, this method can only detect acid reflux. Multichannel intraluminal impedance-pH (MII-pH) monitoring has recently been used for the detection of bolus reflux in infants and children. This method allows for the detection of liquid, gas or mixed reflux in addition to acid, weakly acidic or weakly alkaline reflux. MII-pH monitoring can record the direction of flow and the height of reflux, which are useful parameters to identify an association between symptoms and reflux. However, the technique is limited by its high cost and the lack of normative data of MII-pH in the pediatric population. Despite certain limitations, MII-pH monitoring will become more common and gradually replace pH monitoring in the future, because pH monitoring is part of MII-pH.

• Tribology and Lubricants
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• 제19권2호
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• pp.109-115
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• 2003

Nanotribological characteristics between a Si$_3$N$_4$ AFM tip and hydrophobic thin films were experimentally studied. Tests were performed to measure the nano adhesion and friction in both AFM (atomic force microscope) and LFM (lateral force microscope) modes in various .ranges of normal load. Plasma-modified thin polymeric films were deposited on Si-wafer (100). Results showed that wetting angle of plasma-modified thin polymeric film increased with the treating time, which resulted in the hydrophobic surface and the decrease of adhesion and friction. Nanotribological characteristics of these surfaces were compared with those of other hydrophobic surfaces, such as DLC, OTS and IBAD-Ag coated surfaces. Those of OTS coated surface were superior to those of others, though wetting angle of plasma-modified thin polymeric film is higher.

• Journal of Biosystems Engineering
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• 제18권3호
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• pp.191-198
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• 1993

Vertical and horizontal ride vibrations of the selected agricultural tractors were measured and evaluated with respect to the ISO 2631 'guide for the evaluation of human exposure to whole body vibration'. Evaluation showed that at the normal transportation speeds of 1.4~20km/h on both the concret and ground surfaces tractor drivers were exposed to the vibrations whose magnitudes exceed the 8 hour fatigue decreased proficiency boundary in the frequency ranges of 2~16Hz in vertical and 1~2Hz in horizontal directions. Considering that tractor operation becomes as one of the specialized job for the future farming in Korea, measures must be made to protect the drivers against harmful ride vibrations of agricultural tractors.

• Journal of Nutrition and Health
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• 제31권1호
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• pp.102-107
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• 1998

This study was conducted to investigate the relationship of serum calcium and magnesium levels to depression and anxiety symptoms in 80 homemarker. Fasting blood samples were collected and serum calcium and magnesium concentrations were measured. At the same time, psychological conditions of subjects were estimated by questionnaire. As the result of psychological test, eighty homemarkers were divided into two groups according to psychologicaltest scores. The subjects in one group got high pssycholgoical test scores as high score group (HSG) and the others got low physchological test scores as low score group(LSG). Serum calcium and magnesium concentrations were significantly(p<0.05) lower in HSG than in HSG than in LSG. Many a subject who belonged to HSG appeared to have depression and anxiety symptoms. Drepression and anxiety scores of the subjects with calcium supplementation were significantly (p<0.05) lower than those without calcium supplementation . After calcium supplementation, depressiion and anxiety scores were significantly (p<0.05) decreased in HSG and serum calcium and magnesium concentrations in HSG were significantly increased to normal ranges . This results suggested that psychological conditions of homemarkers might be affected by serum calcium and magnesium levels.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1991년도 추계학술대회 논문집
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• pp.12-16
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• 1991

Cadmium sulphide films with thickness of 0.6∼1.2$\mu\textrm{m}$ were deposited onto corning 7059 glass substrate under a vacuum of 5${\times}$10$\^$-6/ Torr. Source and substrate temperature ranges used were 800∼1100$^{\circ}C$ and 100∼200$^{\circ}C$, respectively. The microstructures and semiconducting properties of the films were studied using X-ray diffraction, UV-VIS-IR spectrophotometer and Hall measurement unit. Electrical resistivity and optical transmission of the CdS films decrease with an increase in source temperature while they increase with an increase in substrate temperature. The resistivity of the film evaporated at 1100$^{\circ}C$ varied from 7${\times}$10$^3$ohm-cm at the substrate temperature of 100$^{\circ}C$ to 2${\times}$10$\_$6/ohm-cm at 190$^{\circ}C$. All the films had hexagonal structure and strong texture with c-axis of grains normal to the substrate glass.

• 한국임상수의학회지
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• 제16권2호
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• pp.506-508
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• 1999

An one-year-old, female pointer dog with conjunctival hyperemia, corneal opaque and ocular pain in right eye was referred to Veterinary Medical Teaching Hospital, Chungbuk National University. In the ophthalmic examination the worm was observed in anterior chamber, The heart worm antigen test was positive. A modified Knott's test was negative. The values of complete blood count and serum chemistry (TP, BUN, creatinine, AST, ALT, ALP, albumin, globuline) showed normal ranges. Any abnormality was not detected in the heart using a thoracic radiography and cardiac sonography. Therefore, this dog was diagnosed as ocular filariasis. The worm was removed by surgical incision through a limbus of cornea. The closure of limbal incision was sutured in a simple interrupted suture pattern with 6-0 silk and the eye was reinflated with sterile saline solution. Antibiotics and dexamethasone ophthalmic solution were applied to right eye every 24 hours for 7 days. To prevent latent filariasis, ivermectin was also administered on day 14 of operation. The heart worm antigen test on day 60 was negative. The dog was successfully cured.

• 한국임상수의학회지
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• 제16권2호
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• pp.529-532
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• 1999

A five-year-old elk (Cervus canadensis) was presented for necropsy to the Veterinary Teaching Hospital, Chungbuk National University, on May 1999. The farmed elk was died on day 5 after velvet antler removal. By history taking, the elk didn't show any clinical signs except for watery diarrhea during 2 days. For the purpose of physical examination at the velvet antler removal, blood was collected from the femoral vein of elk with a mixture of fentanyl-azaperone-xylazine ($Fentazin-10^{\circledR}$). Urine was collected from the bladder within 3 hours after died. Hemato-logical and clincochemical values of the elk showed normal ranges. In the microscopic finding, many round and ellipse sarcocystis were identified in the cardiac muscle fibers without any surrounding inflammatory reaction.

• Journal of Oral Medicine and Pain
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• 제6권1호
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• pp.9-14
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• 1981

Maximal active movements of the mandible in the vertical and the horizontal plane were measured in 106 mem and 78 women. ranging from 20 to 29 years old, with a method devised by agerberg. The studied persons who were dental students of the School of Dentistry Seoul National University (SNU), nurses and dental auxiliaries of the SNU Hospital, had no pain or severe symptoms of dysfunction of the masticatory system. The obtained results were as follows : 1. The mean values for maximal opening and protrusion differed significantly between men and women, 55.9 mm and 49.7 mm, 9.3 mm and 7.4 mm respectively. 2. The means found for maximal lateral movement to the right and to the left were practically the same, 8.5 - 9 mm and did not differ with sex. 3. The lower limit of the normal range of horizontal movements may be regarded as 4 mm for men and 3 mm for women and maximal opening as 44 mm for men and 39 mm for women. 4. The maximal mandibular movement ranges of 20-year old person with 95 % probability were calculated and presented grphically.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.129-136
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• 1998

In this study, lightweight aggregates were developed to see the possible application as a structural uses. For the evaluation purpose, several testings were conducted to compare the physical characteristics between the controlled lightweight aggregates and other lightweight aggregates purchased from different sources. The tests included property changes of fresh concrete and strength characteristics of hardened concrete for both normal and high strength ranges. In addition, a experiment was performed to analyze the freezing and thawing resistance of new lightweight aggregate concrete against other lightweight aggregate concrete against other lightweight aggregate concretes with some experimental parameters such as lightweight aggregates, curing conditions, and water-cement ratio. The test showed that the new lightweight aggregate could be used structural components. Continuous study will be planned for future evaluations.