• 한국해양공학회지
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• 제24권6호
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• pp.51-60
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• 2010

In this study, the performance evaluation of a conventional wave resonator at the entrance of a port or a pier against secondary undulation has been performed using 2D hydrodynamic modeling within port. A wave resonator has been designed for the attenuation of the secondary undulation induced by the long-periodic waves. The controlled performance of the wave resonator has been numerically investigated for CGWAVE MODULE of finite-element model of SMS (Surface water Modeling System) based on the elliptic mild-slope wave equation. SMS was verified though the comparisons with analytical solution performed by Ippen and Goda (1963). Also, It was confirmed that a wave resonator of a rectangular model harbor is effective enough to control the secondary undulation when it compares variation of water level with the case of no resonance system. From the above results, amplification phenomenon induced by long-period waves transferred from 1900 sec to 2100 sec when it applied a wave resonator in Busan Gamcheon Port which is a deep-sea. And it was confirmed that a wave resonator of Pohang New Port attenuates largely long-period waves which are within the range of 300 sec induced by long-period motion of the moored ship.

• 한국식품영양과학회지
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• 제41권11호
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• pp.1559-1564
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• 2012

건포도(Thailand산), 건망고(Philippine산), 건무화과(Iran산)를 0~5 kGy로 감마선 조사한 후 총균수 및 기계적 색차를 측정하고 조사여부 판별가능성을 확인하였다. 총 균수 측정 결과 3 kGy 이상으로 조사된 시료에서는 대부분 검출할 수 없는 수준으로 나타나 미생물학적으로 안전함을 알 수 있었다. 건조과일의 색차 측정에서, 건망고의 색 변화가 방사선조사에 가장 민감하였다. PSL 측정 결과, 건포도의 경우 비 조사시료는 음성으로, 조사시료는 중간 값으로 확인되었고 건망고의 경우 모든 시료가 음성으로 확인되었으며, 무화과의 경우 5 kGy 조사시료만이 양성으로 확인되어, 건조과일의 경우 PSL 측정법은 screening 방법으로의 적용가능성이 낮았다. TL 측정 결과 건무화과의 경우 조사시료는 $150{\sim}200^{\circ}C$ 사이에서 특유의 발광곡선을 나타내었고, 신호 강도 또한 조사선량에 의존적으로 증가하여 TL 적용이 가능하였다. ESR 측정 결과 건포도와 건망고의 경우 조사시료에서 multi-component 신호를 보여주었고, 신호 강도 역시 조사선량에 따라 유의적으로 증가하여 ESR 적용이 가능하였다.

• 대한치과의사협회지
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• 제54권7호
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• pp.529-540
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• 2016

Objective: The objective of this study was to evaluate the osseointegration of narrow-diameter implant with trapezoid-shape and to evaluate the effect of coronal microthreads on trapezoid-shape narrow-diameter implant. Materials and Methods: The experimental narrow-diameter implants were classified into two groups according to absence or presence of coronal microthreads: trapezoid-shape narrow diameter implant (TN group) and trapezoid-shape narrow-diameter implant with microthreads (TNM group). They were installed alternately in bilateral mandible in three dogs. After 8 weeks, the animals were sacrificed. Resonance frequency analysis, removal torque test, and histometric analysis were performed. Results: Statistically higher implant stability quotient (ISQ) values were observed in TNM group than in TN group at the time of implant installation. However, significant ISQ values difference was not observed between groups at 8 weeks. Both groups showed significantly increased ISQ values at 8 weeks, compared to the time of implant installation. There was no significant difference between groups in removal torque test. Bone-implant contact ratio also showed no significant difference between groups in total and coronal part. Conclusion: Within the limitation of this study, it could be concluded that the trapezoid-shape design on narrow-diameter implant showed successful ossointegration, and the microthreads on coronal part did not result in significant bone-implant contact and biomechanical stability at 8 weeks.

• 음성과학
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• 제8권2호
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• pp.23-37
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• 2001

The primary sound produced by the vibration of vocal folds reaches the velopharyngeal isthmus and is directed both nasally and orally. The proportions of the each component is determined by the anatomical and functional status of the soft palate. The oral sounds composed of oral vowels and consonants according to the status of vocal tract, tongue, palate and lips. The nasal sounds composed of nasal consonants and nasal vowels, and further modified according to the status of the nasal airway, so anatomical abnormalities in the nasal cavity will influence nasal sound. The measurement of nasal sounds of speech has relied on the subjective scoring by listeners. The nasal sounds are described with nasality and nasalization. Generally, nasality has been assessed perceptually in the effect of maxillofacial procedures for cleft palate, sleep apnea, snoring and nasal disorders. The nasalization is considered as an acoustic phenomenon. Snoring and sleep apnea is a typical disorders due to abundant velopharynx. The sleep apnea has been known as a cessation of breathing for at least 10 seconds during sleep. Several medical and surgical methods for treating sleep apnea have been attempted. The uvulopalatopharyngoplasty(UPPP) involves removal of 1.0 to 3.0 cm of soft palate tissue with removal of redundant oropharyngeal mucosa and lateral tissue from the anterior and sometimes posterior faucial pillars. This procedure results in a shortened soft palate and a possible risk following this surgery may be velopharyngeal malfunctioning due to the shortened palate. Few researchers have systematically studied the effects of this surgery as it relates to speech production. Some changes in the voice quality such as resonance (nasality), articulation, and phonation have been reported. In view of the conflicting reports discussed, there remains some uncertainty about the speech status in patients following the snoring and sleep apnea surgery. The study was conducted in two phases: 1) acoustic analysis of oral and nasal sounds, and 2) evaluation of nasality.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.295-295
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• 2010

생체 식립형 임플란트의 경우 성공도는 매식체의 골유착 정도에 크게 영향을 받는다. 골유착 시 임플란트의 표면 형상과 하중, 골질의 양 등 많은 요인에 영향을 받게 되므로, 임플란트의 안정성을 주기적으로 점검해야할 필요가 있다. 따라서 임플란트 안정성을 공진 주파수 분석법을 이용하여 측정하기 위해 압전소자 제작과 트랜스듀서의 구조를 설계하였다. 유한요소 해석을 통하여 압전소자와 트랜스듀서의 두께와 크기 변화를 통해 측정 주파수 범위를 10kHz대역으로 맞추었으며, 해석 결과를 토대로 샘플제작과 평가를 실시하였다. 평가 결과 시뮬레이션 해석결과와 유사한 10kHz의 주파수 대역을 가지는 것을 볼 수 있었고, 식립된 나사의 고정도가 증가할수록 주파수가 점차 증가하는 결과를 얻을 수 있었다.

• 생물정신의학
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• 제15권1호
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• pp.46-53
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• 2008

Posterior cortical atrophy(PCA) is a presenile dementia that presents primarily with signs and symptoms of cortical visual dysfunction, while memory is relatively preserved until the late stage of the disease. We report a patient with PCA, confirmed by brain magnetic resonance imaging (MRI) and $F^{18}$-fluorodeoxyglucose positron emission tomography(FDG PET). A 58-year-old right-handed woman presented initially with visual dimness and difficulty finding things around her. She had partial Balint's syndrome, partial Gerstmann syndrome, and idiomotor apraxia. She also had a mild memory disturbance, but preserved insight of her disease. Neuropsychological evaluation showed decreased parietal and left temporal functions bilaterally. Brain MRI and $F^{18}$-FDG PET revealed typical bilateral occipitoparietal atrophy and hypometabolism, which were slightly worse on the right side. Cholinesterase inhibitor administration for 6 months improved the memory impairment slightly, but not the cortical visual dysfunction. This is a typical case of PCA, confirmed by neurologic signs and imaging findings.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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• pp.135-135
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• 2001

Purpose： To know the differences of the proton MR spectroscopic features of the liver between th patients with graft-versus-host disease (GVHD) and without GVHD (non-GVHD) after to marrow transplantation (BMT), and to evaluate the possibility to discriminate GVHD fro non-GVHD by analysis of the in vivo proton MR spectra. Method： We evaluated the in vivo proton MR spectra from the livers of 37 patients wh underwent BMT. Our series included 14 cases with GVHD and 23 without GVHD in the liver. Nineteen men and 18 women were included in our series. All cases of GVHD and 2 o non-GVHD were confirmed by liver biopsy and remaining of non-GVHD by evaluation clinical follow up. Proton MR spectroscopy (1H-MRS) was performed at 1.5T GE Sign Horizon (GE Medical System, Milwaukee, USA) system using localized proton STEAM sequence and body coil in all cases with subjects were located in supine position. N respiratory interruption was required during the spectroscopic signal acquisition. Paramete using in MRS were： TR = over 3000ms, TE = 30ms, number of scans = 128, voxel size = ($2{\times}2{\times}2$)$cm^3$, and one NEX. We evaluated the spectra with an attention to the differences o patterns of the peaks between GVHD and non-GVHD groups. The ratio of peak area of peaks at 1.6-4.1ppm to lipid (0.9-1.6ppm) [P(1.6-4.1ppm)/P(0.9-1.6ppm)] was calculated in GVHD and non-GVHD group, and compared the results between these groups. We als evaluated the sensitivity and specificity for discriminating GVHD from non-GVHD by anal of 1H-MRS.

• Clinical and Experimental Pediatrics
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• 제54권5호
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• pp.219-223
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• 2011

McKusick-Kaufman syndrome (MKS) is an autosomal recessive multiple malformation syndrome characterized by hydrometrocolpos (HMC) and postaxial polydactyly (PAP). We report a case of a female child with MKS who was transferred to the neonatal intensive care unit of Seoul National University Children's Hospital on her 15th day of life for further evaluation and management of an abdominal cystic mass. She underwent abdominal sonography, magnetic resonance imaging, genitography and cystoscopy which confirmed HMC with a transverse vaginal septum. X-rays of the hand and foot showed bony fusion of the left third and fourth metacarpal bones, right fourth dysplastic metacarpal bone and phalanx, right PAP and hypoplastic left foot with left fourth and fifth dysplastic metatarsal bones. In addition, she had soft palate cleft, mild hydronephroses of both kidneys, hypoplastic right kidney with ectopic location and mild rotation, uterine didelphys with transverse vaginal septum and low-type imperforated anus. She was temporarily treated with ultrasound-guided transurethral aspiration of the HMC. Our patient with HMC and PAP was diagnosed with MKS because she has two typical abnormality of MKS and she has no definite complications of retinal disease, learning disability, obesity and renal failure that develop in Bardet-Biedl syndrome, but not in MKS until 33 months of age. Here, we describe a case of a Korean patient with MKS.

• Clinical and Experimental Pediatrics
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• 제54권5호
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• pp.224-227
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• 2011

A sclerosing stromal tumor of the ovary is an extremely rare benign tumor; it usually is found during the second and third decades of life. Patients present with pelvic pain or a palpable abdominal mass. Hormonal effects such as masculinization are uncommon. Here, an 11-year old premenarchal girl presented with deepening of the voice. In addition, clitoromegaly and hirsutism with a male suprapubic hair pattern were observed. The laboratory findings showed that the testosterone level was elevated to 3.67 ng/ml, andostenedione to above 10 ng/ml, dehydroepiandrosterone-sulfate to 346 ${\mu}g$/dl and 17-hydroxy progesterone (17-OHP) to 11.28 ng/ml. The chromosome evaluation revealed a 46,XX female karyotype. An adrenocorticotropic hormone stimulation test was performed. The 17-OHP to cortisol ratio in 30 minutes was 0.045, which suggested a heterozygote for the 21-hydroxylase deficiency. However, the CYP21A2 gene encoding steroid 21-hydroxylase showed normal. The pelvic ultrasound showed a heterogeneous mass consisting of predominantly solid tissue in the pelvic cavity. The pelvic magnetic resonance imaging revealed an $8.9{\times}6.2{\times}6.6$ cm mass of the left ovary. A left oophrectomy was performed and microscopic examination confirmed a sclerosing stromal tumor. Immunohistochemical studies showed that the tumor was positive for smooth muscle actin and vimentin, but negative for S-100 protein and cytokeratin. Following surgery, the hormone levels returned to the normal range and the hirsutism resolved.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.506-508
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• 2002

As an advancement of medical imaging modalities and analyzing software with multi-function, active researches to acquire high contrast and high resolution image being done. In recently, development of medical imaging modalities like as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) is aiming to display anatomical structure more accuracy and faster. Thus, one of the important areas in CT today is the use of CT scanner for the quantitative evaluation of 3-D reconstruction images from 2-D tomographic images. In CT system, the effective slice thickness and the quality of 3-D reconstructed image will be influenced by imaging acquisition parameters (e.g. pitch and scan mode). In diagnosis and surgical planning, the accurate distance measurements of 3-D anatomical structures play an important role and the accuracy of distance measurements will depend on the acquisition parameters such as slice thickness, pitch, and scan mode. The skull phantom was scanned with SDCT for various acquisition parameters and acquisition slice thicknesses were 3 and 5 mm, and reconstruction intervals were 1, 2, and 3 mm to each pitch. 3-D visualizations and distance measurements were performed with PC based 3-D rendering and analyzing software. Results showed that the image quality and the measurement accuracy of 3-D SDCT images are independent to the reconstruction intervals and pitches.