• Korean Journal of Bronchoesophagology
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• v.15 no.1
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• pp.28-34
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• 2009

Background and Objectives: Foreign bodies of upper aerodigestive tract are common problem for primary care physicians. Delayed diagnosis or failure of removal might cause fatal problemsand complications. Therefore proper diagnosis and management is imperative. In this study, we described clinical features of upper aerodigestive tract foreign body, and analyzed efficacy of different management modality. Materials and Methods: 250 cases of foreign bodies in the esophagus and trachea, between Jan. 1998 through Jan. 2009 has been retrospectively analyzed. A total of 24 cases and 226 cases had been found each as airway foreign bodies and esophageal foreign bodies. The clinical features are described and treatment outcomes, prognosis, and rate of complications of each management modality have been compared. Results: In airway foreign bodies, ventilating bronchoscopy yielded better results, 19 success out of 19 trials than fiberoptic bronchoscopy, 3 success out of 5 trials. Hospitalization days after removal of foreign body didn't show difference between two treatment modalities, although patients who had ventilating bronchoscopy had gone through general anesthesia. And there was no complication after removal of foreign body. In esophageal foreign bodies, rigid esophagoscope yielded better results, 99% of successful removal rate, compared to the EGD, only 78% of successful removal rate. There was no difference of hospitalization days between two modalities. And complication rate was even low in patients who had done rigid esophagoscopic foreign body removal. Conclusion: In upper aerodigestivetract foreign body. Rapid diagnosis and successful foreign body removal is important. Removal by rigid scope(ventilating bronchoscope, rigid esophagoscope) revealed less failure in both airway and esophageal foreign bodies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2513-2533
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• 2018

In cognitive radio technology, the overall efficiency of communications systems can be improved without allocating additional bands by allowing a secondary system to utilize the licensed band when the primary system, which has the right to use the band, does not use it. In this paper, we propose a fast and reliable common channel initialization protocol without any exchange of initialization messages between the cluster head and the member nodes in cognitive ad-hoc networks. In the proposed method, the cluster and member nodes perform channel-based spectrum sensing. After sensing, the cluster head transmits a system activation signal through its available channels with a predetermined angle difference pattern. To detect the cluster head's transmission channels and to join the cluster, each member node implements fast Fourier transform (FFT) and computes autocorrelation for the angle difference sequence of the received signal patterns. This is compared to the predetermined reference angle difference pattern. The join-request and channel-decision procedures are presented in this paper. Performance evaluation of the proposed method is presented in the simulation results.

• Korean Journal of Head & Neck Oncology
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• v.18 no.2
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• pp.203-206
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• 2002

Metastatic carcinomas to the thyroid gland are rare, and thyroid involvement by secondary carcinomas commonly results from direct the extension of malignant cells from adjacent organs such as the larynx or the trachea. The common primary sites of thyroid metastasis are kidney, breast, lung, and lymphoid tissue. Among head and neck cancers, nasopharyngeal carcinoma has a relatively high incidence of distant metastases to other sites and commonly involving sites are bone, lung, and liver. Recently, we experienced a case of a 43-year-old male who had been presented with neck mass for 3 months. He was diagnosed non-keratinizing nasopharyngeal carcinoma in 1993. And, thyroid metastasis of nasopharyngeal carcinoma was confirmed by total thyroidectomy. So we report this rare case with the review of literatures.

• Journal of Nutrition and Health
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• v.36 no.9
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• pp.966-973
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• 2003

The purpose of this study was to investigate the utilization level of forecasting methods in contract foodservice management companies. Questionnaires were distributed and collected from 30 foodservice management companies contracted with universities and 49 university foodservices in Seoul and Kyungki area. Statistical data analysis was performed using SPSS/WIN 10.0 based on the production records of Yonsei University foodservices and the weather reports from a meteorological observatory. The results of this study were as follows: 1) The objectives of the fore-casting systems were identified as saving costs through eliminating the leftover, meeting the customer demands, and improving efficiency in food preparation.2) All of the university foodservices were already performing the forecasting methods but in foodservice management companies as a whole,89.7 percents were applying the method and only 55.2 percents had the separate forecasting department. 3) A large number of foodservice staffs in the head office (65.5％) answered that they often utilized intuitive estimates based on the past experiences and records for forecasting while 65.3% managing staffs in the university foodservices answered the same.4) Both in the head office and university foodservices, actual number of meals served were recorded. In the head office, mostly estimated numbers and actual numbers of meals were recorded while estimated, prepared, and actual numbers of meals served were recorded for most of the cases in university foodservices. 5) The primary factors considered for forecasting were the actual production records for the last month, the customer preference for the selected menu items, and the specific day of the week.

• Applied Microscopy
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• v.26 no.3
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• pp.267-275
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• 1996

The internal ultrastructural changes of germ cells and external morphology of spermatozoon during the spermatogenesis in the rockfish, Sebastes inermis were studied using transmission and scanning electron microscope. The testis is seminiferous tubule type in internal structure. Seminiferous tubule consist of many cyst which contain numerous germ cells in same developmental stage. Spermatogonium contained a large nucleus with single nucleolus in interphase. Primary spermatocyte identified by the presence of synaptonemal complex in nucleus and the contained a number of mitochondria, endoplasmic reticula and Golgi bodies in cytoplasm. The nucleoplasm of secondary spermatocyte was more concentrated than that of the previous phase. Spermatids were more condensed in nucleus and cytoplasm, and show the long-spherical shape. In the cytoplasm of spermatid mitochondria located to lower portion of the nucleus and Golgi bodies located to upper portion, but proacrosomal granule is not appeared. The spermatozoon consist of the head and tail. No acrosome could be found in the head. The cytoplasmic collar of posterior part in sperm head contained mitochondria which surrounded axial filament. The well developed axonemal lateral fins were identified in sperm flagellum, and the axial filament of the flagellum consist of nine pairs of peripheral microtubules and one pair of central microtubules.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.806-811
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• 2001

Since the characteristics of combustion and pollutant in Diesel engines were mainly effected by the characteristics of in-cylinder gas flow and fuel spray, an understanding of those was essential to the design of the D.I. Diesel engines. The improvement of volumetric efficiency of air charging into combustion chamber is a primary requirement to obtain better mean effective pressure of an engine. Since parameters such as the air resistances in intake and exhaust flow passages, valve lift and valve shape influence greatly to the volumetric efficiency, it is very important to investigate the flow characteristics of intake and exhaust port which develops air motion in the combustion chamber. In this study, two approach methods were used for design intake and exhaust port; experiment and computation which were made by using steady flow test rig and commercial CFD code. This paper presents the results of an experimental and analytical investigation of steady flow through the prototype cylinder head ports and valves of the HHI's H21/32 HIMSEN Engine.

• Korean Journal of Head & Neck Oncology
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• v.18 no.1
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• pp.76-79
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• 2002

Temporoparietal fascial flap (TPFF) has been used in the reconstruction of a broad spectrum of complex defect of head & neck it can be used as pedicled flap or free flap. TPFF is extensively is good for reconstruction of auricular defects because it is fascial flap with ease of covering irregular surface. TPFF is supplied by the superficial temporal artery & vein and innervated by zygomatico-temporal branch of facial nerve and auriculotemporal nerve. The flap ranges from 2-4mm in thickness and can be harvested up to 17x14cm wide, it can include calvarian bone and enables primary closure of donor site. We carried out reconstruction of oral cavity defects by means of TPFF with a satisfactory result in two cases of oral cavity cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.87-91
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• 2016

To investigate whether excision repair cross complementing-group1 (ERCC1) expression status could serve as a bio-predictor of response to platinum-based induction chemotherapy for head and neck cancers (HNCs) patients with a diagnosis of epithelial HNC were studied retrospectively. Paraffin embedded tumor samples of the patients were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) to determine ERCC1 expression status and its correlation with response to platinum-based induction chemotherapy was investigated. Of 44 included patients, 33 were male (75%) and 11 were female (25%) with a mean age of 53 years. Some 36% of patients whose tumor samples had high ERCC1 expression showed no response to induction chemotherapy. The value for patients with low ERCC1 expression was 9% and the difference was statistically significant (p=0.03). The ERCC1 expression state did not significantly vary between patient groups according to sex, age, primary tumor site, and tumor and node stage. Our study indicates that ERCC1 expression status detected by RT-PCR might serve as a bio-predictor of response to platinum-based induction chemotherapy for epithelial HNCs.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.68-74
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• 1998

Performance and efficiency of deep seabed collector is a primary factor for feasibility of commercial deep ocean mining. The efficiency of manganese nodules collector depends on vehicle mobility relative to undulating seafloor and is attributed pickup head to keep altitude and elevation of it against seafloor. For this reason, motion control of pickup head relative to the changing deep-sea topography and other disturbances is of particular importance in design of pickup device. The concept of design axiom is applied to a pickup device of hybrid type in order to evaluate the concept design. Kinematic analysis conducted in absolute Cartesian coordinates gives position, velocity, and acceleration of the hydraulic cylinders which enable the pickup head to keep the preset optimal distance from seafloor. Inverse dynamic analysis provides the driving forces of hydraulic cylinders and the reaction forces at each joint. Design sensitivity analysis is performed in order to investigate the effects of possible design variables on the change of the maximum strokes of hydraulic cylinders. The direct differentiation method is used to obtain the design sensitivity coefficients.

• Nuclear Engineering and Technology
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• v.41 no.10
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• pp.1323-1332
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• 2009

The IHX (Intermediate Heat eXchanger) for a pool-type SFR (Sodium-cooled Fast Reactor) system transfers heat from the primary high temperature sodium to the intermediate cold temperature sodium. The upper structure of the IHX is a coaxial structure designed to form a flow path for both the secondary high temperature and low temperature sodium. The coaxial structure of the IHX consists of a central downcomer and riser for the incoming and outgoing intermediate sodium, respectively. The IHX of a pool-type SFR is supported at the upper surface of the reactor head with an IHX support structure that connects the IHX riser cylinder to the reactor head. The reactor head is generally maintained at the low temperature regime, but the riser cylinder is exposed in the elevated temperature region. The resultant complicated temperature distribution of the co-axial structure including the IHX support structure may induce a severe thermal stress distribution. In this study, the structural feasibility of the current upper support structure concept is investigated through a preliminary stress analysis and an alternative design concept to accommodate the IHTS (Intermediate Heat Transport System) piping expansion loads and severe thermal stress is proposed. Through the structural analysis it is found that the alternative design concept is effective in reducing the thermal stress and acquiring structural integrity.