• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2004년도 제20회 발표논문집
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• pp.131-134
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• 2004

A lot of foreign objects(ceramics, pottery, bronze, glassware and coins, etc.) have been found in the archaeological sites in Korea. These foreign objects are the evidences of the cultural exchanges of that time, whose scale and routes are an important part of the studies in ancient history. So it is crucial to accumulate basic reference information such as the raw materials and the production method of these objects through scientific researches, along with archeological researches. These scientific research materials provide a basis for finding the importing route and the origin of these objects. Besides, we can find out extraordinary and distinctive production technique by comparison with tile domestic objects. This article reports the result of an analysis, performing on 36 samples of the glassware fragments excavated from the South Tomb of the Hwangnamdaechong, to verify their components and note peculiar features. We have analyzed the major and minor components of 10 elements, and then by using these data examined the differences in the composition of components, varying with the origin and color of glassware. We used the PCA(principal component analysis) as the statistical method to classify the sample in order to find out how the samples formed groups.

• 항공우주시스템공학회지
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• 제10권3호
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• pp.52-58
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• 2016

The elastomeric O-ring is the most-commonly-used seal due to its excellent sealing capacity, and its availability in various costs and sizes; furthermore, its importance has lasted over a long duration. However, a dearth of research exists in Korea regarding the elastomeric O-ring and the corresponding techniques. The constituent parts of elastomeric rubber are important; to determine their properties, the uni-axial tension and equi-biaxial tension need to be tested. Also, the non-linear analysis method reduces the design cost. An O-ring failure causes leaks and vibration. In this paper, foreign objects are used to affect an O-ring and its performance so that all angles of the O-ring design can be considered. This paper presents a solution for the O-ring-failure problem using a finite-element analysis.

• Journal of information and communication convergence engineering
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• 제19권1호
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• pp.61-66
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• 2021

An underwater remotely operated vehicle (ROV) has been implemented. It can inspect foreign substances through a CCD camera while the ROV is running in water. The maximum thrust of the ROV's running thruster is 139.3 N, allowing the ROV to move forward and backward at a running speed of 1.03 m/s underwater. The structural strength of the guard frame was analyzed when the ROV collided with a wall while traveling at a speed of 1.03 m/s underwater, and found to be safe. The maximum running speed of the ROV is 1.08 m/s and the working speed is 0.2 m/s in a 5.8-m deep-water wave pool, which satisfies the target performance. As the ROV traveled underwater at a speed of 0.2 m/s, the inspection camera was able to read characters that were 3 mm in width at a depth of 1.5 m, which meant it could sufficiently identify foreign objects in the water.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권3호
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• pp.187-195
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• 2022

Background: This retrospective study investigated the incidence rate of accidental foreign body aspiration and ingestion according to patient sex, age, and dental department. This study aimed to verify whether the incidence rate is higher in geriatric than in younger patients and whether it is different among dental departments. Methods: Accidental foreign body aspiration and ingestion cases were collected from electronic health records and the safety report system of Yonsei University Dental Hospital from January 2011 to December 2017. The collected data included patients' age, sex, medical conditions, treatment procedures, and foreign objects that were accidentally aspirated or ingested. The incidence rate was calculated as the number of accidental foreign body aspirations and ingestions relative to the total number of patient visits. Differences depending on the patients' sex, age, and dental department were statistically identified. Results: There were 2 aspiration and 37 ingestion cases during the 7-year analysis period. The male to female incidence ratio was 2.8:1. The incidence rate increased with age and increased rapidly among those aged 80 years or older. Seven of the 37 patients with accidental foreign body ingestion had intellectual disability, Lou Gehrig's disease, dystonia, or oral and maxillofacial cancer. The incidence rate was highest in the Predoctoral Student Clinic and the Department of Prosthodontics. The most frequently swallowed objects were fixed dental prostheses and dental implant components. Conclusion: The incidence rate of accidental foreign body aspiration and ingestion differed according to patient sex, age, and dental department. Dental practitioners must identify high-risk patients and apply various methods to prevent accidental foreign body aspiration and ingestion in dental clinics. Inexperienced practitioners should be particularly careful.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2008년도 춘계학술발표대회 개요집
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• pp.10-10
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• 2008

• 아동학회지
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• 제37권4호
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• pp.159-168
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• 2016

Objective: This study investigated the age at which monolingual children can understand that different languages are different conventional systems of communication. In particular, we investigated when children can suspend using the mutual exclusivity (ME) assumption that a label solely refers to one category when interpreting novel words from foreign languages. Methods: Two-year-olds (n = 16) and 3-year-olds (n = 16) participated in the procedure, which consisted of three blocks. In the first block, a Korean speaker taught the children a novel word, muppi, referring to a novel object. The children were presented with two objects, muppi and another novel object. The Korean speaker then asked the children to find a referent of either muppi or the other novel Korean label, kkati. In the second block, a foreign language (either English or Spanish) speaker asked children to find the object for a foreign novel word, sefo, presenting two objects: muppi and the third novel object, which had not been presented before. The procedure of the third block was identical to that of the first block. Results: Three-year-olds exploited the ME assumption when interpreting a Korean novel word but not when interpreting a foreign novel word. In contrast, 2-year-old children did not use the ME assumption when interpreting native and foreign words. Conclusion: Children acquire an understanding that native and foreign languages have different words for an object at least by 3 years of age.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.725-726
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• 2005

• 한국항공운항학회지
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• 제30권1호
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• pp.12-19
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• 2022

The exhaust wake of an aircraft engine is discharged in a high temperature and high speed, which can damage objects such as an aircraft in the rear. The exhaust wake can lift small foreign substances lying on the ground or falling off, and the floating foreign substances can enter the intake duct of the aircraft moving from the rear and cause engine FOD (Foreign Object Damage). This study experimentally analyzed how the engine exhaust wake generated from military jet fighters affects the movement of foreign substances and evaluated the effects of foreign substances on the damaged area by measuring wake velocity. The simulation and field experimental results confirmed that the effect of exhaust wake increases as the rear position closer, and that foreign substances lifted by the wake can act as FOD to the adjacent rear aircraft.

• Journal of Information Processing Systems
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• 제15권1호
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• pp.34-46
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• 2019

A method for detecting foreign substances in mould based on scatter grams was presented to protect moulds automatically during moulding production. This paper proposes a wavelet transform foreign detection method based on Monte Carlo analysis mechanism to identify foreign objects in the tube. We use the Monte Carlo method to evaluate the image, and obtain the width of the confidence interval by the deviation statistical gray histogram to divide the image type. In order to stabilize the performance of the algorithm, the high-frequency image and the low-frequency image are respectively drawn. By analyzing the position distribution of the pixel gray in the two images, the suspected foreign object region is obtained. The experiments demonstrate the effectiveness of our approach by evaluating the labeled data.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권3호
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• pp.428-434
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• 1996

The practice of oral surgery or other dentistry possesses the danger of causing the loss of foreign bodies used within the oral cavity. If such foreign bodies would be lost, they could enter the viscera through the esophagus or tracheobroncheal tree. Ingestion is four times as frequent as aspiration and 80% to 90% of ingested foreign bodies will pass through the body spontaneously. Once the aspiration or ingestion of foreign bodies is happened, a dental procedure should be discontinued immediately. If symptoms of respiratory distress, including coughing, wheezing, or stridor, are present, a patent airway should be maintained, oxygen administered, and ventilation supported if necessary. The PA chest radiograph will identify the objects in the lung, esophagus, or stomach. Ingested gastrointestinal foreign bodies may be managed by observation, endoscopy, and or surgical intervention and aspirated tracheobroncheal foreign bodies may be managed by bronchoscopy, and or surgical intervention. This case report describes the management of ingested or aspirated foreign bodies happened to the three patients during intraoral treatment. we recommend that the preventive method of ingestion or aspiration of the dental foreign bodies should be performed prior to intraoral treatment and the immedieate measures should be carried out after ingestion or asipiration of it.