• Journal of Korean Port Research
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• 제8권2호
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• pp.57-65
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• 1994

A theoretical formulation is performed to investigate the wave reflection and transmission ratios by a submerged multi-layered rubble-mound breakwater. This theory, which is based on the linear boundary integral method, can be extended to the multi-layered breakwater with arbitrary cross section. In the theoretical analysis evanescent mode wave is not considered, since fictitious open boundaries are put on the places far from the structure. Therefore the mathematical presentation may be simpler, and computational time shorter. The validity of obtained numerical results is demonstrated by comparing with ones of impermeable and permeable breakwaters. Comparison shows resonable agreement. On the basis of these verifications this theory is applied to the one and two-layered submerged rubble-mound breakwater with trapezoidal type.

• Journal of Korean Neurosurgical Society
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• 제39권3호
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• pp.192-197
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• 2006

Objective : Eleven patients treated with posterior cerebral artery[PCA] aneurysm during 6.3-years period are retrospectively reviewed to determine treatment outcome. Methods : Eleven patients with PCA aneurysm were treated from January 1998 to May 2004. Their medical records and radiologic studies were reviewed retrospectively. The records of these patients were analysed with particular reference to their demographic details, mode of presentation, and treatment outcome. Results : Of the 11 patients, 8 patients presented with symptoms related aneurysmal bleeding. Three patients had unruptured PCA aneurysms. Open or endovascular surgery was performed in 9 patients; None of these patients exhibited a third nerve palsy, visual field deficit, or hemiparesis at the time of presentation. Postoperatively, 2 made a good recovery, 2 had a moderate disability because of cerebral infarction after surgery, and 5 had a severe disability because of cerebral infarction after surgery. Of 2 conservatively treated patients, 1 was doing well but the other died as a result of brain swelling. Conclusion : The treatment of the PCA aneurysms is difficult regardless of the aneurysmal size, site, and treatment modality. All reasonable treatment to reduce the risk of associated morbidity should be considered.

• Journal of Information Technology Applications and Management
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• 제28권3호
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• pp.59-75
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• 2021

This study aims to establish a foundation for autonomous driving on campus and communication of abundant university information in the HCI environment in a VR environment where college freshmen can freely travel around campus facilities. The purpose of this study is to develop a three-dimensional VR-style campus tour system to establish a media environment to provide abundant university information guidance services to freshmen in non-face-to-face situations. This study designed a three-dimensional virtual reality campus tour system to solve the problem of discontinuity in which VR360 filming space does not lead to space like reality, and to solve many problems of expertise in VR technology by constructing an integrated production environment of tour system. We aim to solve the problem of inefficiency, which requires a large amount of momentum in virtual space, by constructing a GUI that utilizes the motion of the field of view focus. The campus environment was designed as a three-dimensional virtual reality using a three-dimensional graphic design. In non-face-to-face situations, college freshmen freely transformed the HMD VR device, smartphone, FPS operation mode of the gyroscope sensor. The design elements of the three-dimensional virtual reality campus tour system were classified as ①Visualization of factual experiences, ②Continuity of space movement, ③Operation, automatic operation mode, ④Natural landscape animation, ⑤Animation according to wind direction, ⑥Actual space movement mode, ⑦Informatization of spatial understanding, ⑧GUI by experience environment, ⑨Text GUI by building, ⑩VR360, 3D360 Studio Environment, ⑪Three-dimensional virtual space coupling block module, ⑫3D360-3D Virtual Space Transmedia Zone, ⑬Transformable GUI(VR Device Dual Viewer-Gyro Sensor Full Viewer-FPS Operation Viewer) and an integrated production environment was established with each element. It is launched online (http://vautu.com/u1) by constructing a GUI for free driving mode and college information screens to adapt to college life for freshmen, and designing an environment that can be used simultaneously by current media such as PCs, Android, and iPads. Therefore, it conducted user research, held a development presentation, a forum on excellence in university innovation support projects, and applied it as a system on the website of a particular university. College freshmen will be able to experience university information directly from the web and app to the virtual reality campus environment.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.203-203
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• 2015

Gallium Oxide (Ga2O3) has been widely investigated for the optoelectronic applications due to its wide bandgap and the optical transparency. Recently, with the development of fabrication techniques in nanometer scale semiconductor materials, there have been an increasing number of extensive reports on the synthesis and characterization of Ga2O3 nano-structures such as nano-wires, nano-belts, and nano-dots. In contrast to typical vapor-liquid-solid growth mode with metal catalysts to synthesis 1-dimensional nano-wires, there are several difficulties in fabricating the nano-structures by using sputtering techniques. This is attributed to the fact that relatively low growth temperatures and higher growth rate compared with chemical vapor deposition method. In this study, Ga2O3 nanowires (NWs) were synthesized by using radio-frequency magnetron sputtering method. The NWs were then coated by Au thin films and annealed under Ar or N2 gas enviroment with no supply of Gallium and Oxygen source. Several samples were prepared with varying the post annealing parameters such as gas environment annealing time, annealing temperature. Samples were characterized by using XRD, SEM, and PL measurements. In this presentation, the details of fabrication process and physical properties of branched Ga2O3 NWs will be reported.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제23권9호
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• pp.91-97
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• 2009

We have constructed the it's cause diagnosis system of power cable by Failure Mode Effect Analysis(FMEA) method because we have to cause analysis when the cable accident happened. This system was composed of data input of accident condition, presentation of the shape through pictograph and accident probability by FMEA method. According to each selection, the accident cause comments are showed by the accident occurrence possibility. Also, the verification of the it's diagnosis system through the cause analysis of the cable accident cases, the system agreed well with results that analyzed actual state.

• Advances in pediatric surgery
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• 제5권1호
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• pp.69-74
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• 1999

Condyloma acuminata, an uncommon disease m the pediatric patients, is being reported with increasing frequency in both adults and children. During the last 10 years, we managed 11 children with condyloma acuminata of the anogenital area. The patients' age at presentation varied from 9 months to 11 years, and boys outnumbered girls by a ratio of 2 : 1. The lesions were found in the perianal area in 9 patients and the genital area in 2. No history of sexual contact or abuse could be elicited. Although the exact mode of transmission of human papillomavirus(HPV) couldn't be defined, maternal-infant transmission at birth and close nonsexual family contact were the main possible causes of HPV infection in our patients. Our experience suggest that fulguration of the warts and concomitant excision with scissors of the larger lesions are the most satisfactory method of treatment in children. However, condyloma acuminata have high recurrence rate despite these treatments. Viral typing and careful epidemiological investigation on a larger series of patients may clarify the causative factors and effective modalities of treatment in childhood anogenital condyloma acuminata.

• Korean journal of communication and information
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• 제16권
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• pp.108-135
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• 2001

This study examines the structure of the problems of Korean newspaper reporting raised by the civil society. Based on the differences in the mode of presentation, the problems of newspaper reporting were classified into three types; prominent, associated, and isolate problem. The relations among these problems were defined as the degree of co-occurrence in the monitoring articles. A network analysis was conducted to examine the structure of the problems in Korean newspaper reporting. A $33{\times}33$ similarity matrix of the problems was created by analyzing the data from one monitoring report and two weekly media critics newspapers. The results showed that of the 33 problems, most of them were mentioned as prominent or associated problems. The problems related to the news contents were mostly treated as prominent ones, while the problems about the news writing and reporting styles were frequently treated as associated ones. The network structure of newspaper criticism based on the co-occurrence of 33 problems were divided into six clusters. Among them, the most central was the group including the problems of "unfairness,' "biased interpretation," and "vagueness". In addition, the problems were found to have different roles in the network. Of the 33 problems, two were liaisons and four were attached isolates, indicating the hierarchical structure of problems in newspaper reporting. These results were discussed in the light of two viewpoints; the absence of objective criteria in media criticism, and the need for the comparisons of the current study's results with the opinions of newspaper readers and journalists. finally, the implications for the future studies were presented.

• Journal of Trauma and Injury
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• 제29권2호
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• pp.37-42
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• 2016

Purpose: Arterial injury in children is a challenging problem for its special characteristics. It is rare even during warfare. This review described a personal experience in the management and outcome of acute pediatric arterial injuries of extremities. Methods: Thirty-six children below age of 13 years were studied during period from 2004 through 2014 in Iraq. Results: Male patients were 27 (75%) and female were 9 (25%). Seven to twelve years old was the most affected age group. The incidence of iatrogenic injuries was greater in infants and toddlers while penetrating injuries were the most common in older children. Upper limbs arteries were affected in 17 (47.2%) and lower limb in 19 (52.8%) patients. Hard signs were the commonest mode of presentation (83.3%). Lateral wall tear and complete transection were the most frequent types of arterial injury (36.1% and 27.8% respectively). The most frequent procedures performed were end-to-end anastomosis and lateral arteriorrhaphy. Surgical outcome was good. In 27 cases distal pulsations were regained. Seven cases had impalpable distal pulses but still viable limbs. Limb length discrepancy was detected in one case. One case was complicated with limb loss. No death was recorded. Conclusion: Arterial injuries in children are age related. The proper treatment of arterial injuries in children requires high index of suspicion, early operative intervention and continuous postoperative follow-up throughout years of active growth. Angiogram has a limited role as a diagnostic tool in acute arterial injuries.

• Korean Journal of Head & Neck Oncology
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• 제4권1호
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• pp.53-58
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• 1988

We have experienced 3 cases of papillary carcinoma of the thyroid gland seen as lateral neck cyst, Usually cystic lesions of the neck have been considered as benign lesions from clinical viewpoint. The usual differential diagnosis includes branchial cleft cyst, cystic hygroma, dermoid cyst, cold abscess(tuberculous lymphadenitis) and cavitating squamous cell carcinoma. A lateral neck cyst as the sole presenting complaint of the papillary thyroid carcinoma is very rare. Preoperative diagnosis of lateral neck cyst is often diagnostic dilemma. Fine-needle aspiration cytology can be helpful in detecting the cancer cells and in demonstrating the nature of the fluid component of the lateral neck cyst. Presence of brown murky fluid from the aspirated fluid is highly suggestive of thyroid carcinoma. The thyroid scans and B-mode ultrasonography mayor may not be helpful to detect the primary focus of the thyroid gland. We suggest that a patient with a lateral neck cyst in adult age group should be considered to be a possibility of underlying thyroid carcinoma presanting as lateral neck cyst.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.462-462
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• 2013

Gallium Oxide (Ga2O3) has been widely investigated for the optoelectronic applications due to its wide bandgap and the optical transparency. Recently, with the development of fabrication techniques in nanometer scale semiconductor materials, there have been an increasing number of extensive reports on the synthesis and characterization of Ga2O3 nano-structures such as nano-wires, nanobelts, and nano-dots. In contrast to typical vaporliquid-solid growth mode with metal catalysts to synthesis 1-dimensional nano-wires, there are several difficulties in fabricating the nanostructures by using sputtering techniques. This is attributed to the fact that relatively low growth temperatures and higher growth rate compared with chemical vapor deposition method. In this study, Ga2O3 chestnut burr were synthesized by using radio-frequency magnetron sputtering method. In contrast to typical sputtering method with sintered ceramic target, a Ga2O3 powder (99.99% purity) was used as a sputtering target. Several samples were prepared with varying the growth parameters, especially he growth time and the growth temperature to investigate the growth mechanism. Samples were characterized by using XRD, SEM, and PL measurements. In this presentation, the details of fabrication process and physical properties of Ga2O3 nano chestnut burr will be reported.