• 한국주조공학회지
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• 제21권5호
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• pp.290-295
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• 2001

We fabricated test samples containing various shape elements and surface roughness checking points for the jewelry cast master patterns by employing the 3D computer aided design (CAD), selective laser sintering (SLS) rapid prototype (RP) with the DuraForm powders. We varied the alignment angle from $0^{\circ}$ to $10^{\circ}$ at a given layer thickness of 0.08 and 0.1mm, respectively, in RP operation. Dimensions of the shape elements as well as values of surface roughness are characterized by an optical microscope and a contact-scanning profilometer. Surface roughness values of the top and vertical face increased as the alignment angle increased, while the other roughness values and shape elements variation were not depending on the alignment angle. The resolution of the shape realization was enhanced as the layer thickness became smaller. The minimum diameter of the hole, common in jewelry design, was 1.2 mm, and the shrinkage became 12% at the 1.6 mm-diameter hole, Our results implied that we face down the proposed design elements with $0^{\circ}$ alignment angle, and consider the shrinkage effect of each shape element in DuraForm RP jewelry modeling.

• 한국산학기술학회논문지
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• 제3권2호
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• pp.110-114
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• 2002

주얼리 제조 공정중 마스터패턴 제조 공정은 전체 제조원가의 20%를 차지하기 때문에 매우 중요한 공정이다. 지금까지는 수작업으로 왁스 패턴을 제작하고 이를 이용하여 석고형을 만들고 석고형으로 마스터 패턴을 제작하는 복잡한 공정을 거쳐 제작하였다. 본 연구는 쾌속조형기를 이용하여 듀라폼 재질의 몰드를 만들고 저융점합금을 이용하여 마스터패턴을 직접 제작하는 새로운 공정을 개발하였다. 듀라폰의 용융진이 190℃ 이므로 용융점 70℃의 Pb-Sn-Bi-Cd 계의 저융점 합금을 주물재료로 이용하여 마스터패턴을 제작하였다.

• Journal of Korean Neurosurgical Society
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• 제49권3호
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• pp.175-177
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• 2011

Subdural empyema is a rare form of intracranial sepsis associated with high morbidity and mortality. The most frequent cause is extension of paranasal sinusitis through emissary veins or of mastoiditis through the mucosa, bone, and dura mater. Development of subdural empyema after pyogenic meningitis is known to be very unusual in adults. We report a rare case of fatal subdural empyema, an unusual complication of pyogenic meningitis. Our bitter experience suggests that subdural empyema should be borne in mind in patient with pyogenic meningitis who exhibit neurological deterioration.

• 한국주조공학회지
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• 제22권5호
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• pp.265-270
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• 2002

A novel jewelry master pattern manufacturing process which reduce manufacturing steps by employing a Duraform rapid prototyping mold and a low melting alloy has been suggested. The novel process follows the steps of 'jewelry 3D CAD design ${\rightarrow}$ Durafrom RP mold ${\rightarrow}$ low melting alloy master pattern' while the previous process follows more complicated steps of 'jewelry idea sketch ${\rightarrow}$ detailed drawing ${\rightarrow}$ wax carving ${\rightarrow}$ flask ${\rightarrow}$ silver master pattern.' An upper and a lower part of molds have been manufactured of Duraform powder, of which melting point is $190^{\circ}C$. A maser pattern was manufactured by pouring a low melting alloy of Pb-Sn-Bi-Cd, so called Woods Metal, of which melting point is $70^{\circ}C$, into the mold. The master pattern is a shape of a disk of 20mm diameter that contains various design factors. The variations of dimensions, surface roughness, surface pore ratio were measured by an optical microscope, a surface roughness profilometer, and a Rockwell hardness tester. The pattern made of were maeasured by an optical microscope, a surface roughness profilometer, and a Rockwell hardness tester. The pattern made of low melting alloy has sufficient surface hardness, and surface pore ratio to be used as the jewelry master pattern.

• 대한소아치과학회지
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• 제32권1호
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• pp.152-157
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• 2005

Hypophosphatemia rickets는 비타민 D의 치료량에 내성을 갖기 때문에 Vitamin D-resistant rickets(VDRR)라고도 명명되며, 이는 요세관으로부터 무기질 인산의 재흡수가 감소됨으로써 혈청 칼슘농도는 정상이나 인산농도가 낮고 alkaline phosphatase가 약간 증가되기 때문에 쉽게 진단되는 구루병의 한 형태이다. 이러한 Hypophosphatemia rickets의 임상적인 소견으로 양다리가 휘는 것. 작은 키, 척추측만. 손목과 발목부위의 팽대가 나타나며 구강내 소견으로는 자발적인 치성농양의 높은 발생률, 맹출 지연, 근단공의 폐쇄지연, 얇고 저형성된 법랑질, 명확히 인지하기 힘든 치조백선, 확대된 치수강, 법랑상아경계까지 연장된 치수각 등이 있다. 본 증례는 유치의 상실과 그에 따른 치료를 위해 본원 소아과에서 의뢰된 비타민 D저항성 구루병 환아의 임상소견과 그 치과적 치료에 대해 보고하는 바이다.

• Anatomy and Cell Biology
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• 제56권4호
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• pp.435-440
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• 2023

Few studies have examined the basilar venous plexus (BVP) and to our knowledge, no previous study has described its histology. The present anatomical study was performed to better elucidate these structures. In ten cadavers, the BVP was dissected. The anatomical and histological evaluation of the intraluminal trabeculae within this sinus were evaluated. Once all gross measurements were made, the clivus and overlying BVP were harvested and submitted for histological analysis. A BVP was identified in all specimens and in each of these, intraluminal trabeculae were identified. The mean number of trabeculae per plexus was five. These were most concentrated in the upper half of the clivus and were more often centrally located. These septations traveled in a posterior to anterior direction and usually, from inferiorly to superiorly however some were noted to travel horizontally. In a few specimens the trabeculae had wider bases, especially on the posterior attachment to the meningeal layer of dura mater. More commonly, the trabeculae ended in a denticulate form at their two terminal ends. The trabeculae were on average were 0.85 mm in length. The mean width of the trabeculae was 0.35 mm. These septations were consistent with the cords of Willis as are found in the lumen of some of the other intradural venous sinuses. An understanding of the internal anatomy of the BVP can aid in our understanding of venous pathology. Furthermore, this knowledge will benefit patients undergoing interventional treatments that involve the BVP.

• 대한소아치과학회지
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• 제43권4호
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• pp.452-460
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• 2016

Burkitt 림프종은 소아에서 호발하는 악성 종양의 하나로 non-Hodgkin B 림프종의 한 형태이다. 매우 빠르게 증식하는 종양으로 구강 내에서 발생시 안면부 부종 및 이환 치아의 동요도와 변위, 치은의 발적 및 부종 등의 증상을 보인다. 본 증례는 5세 남환으로 왼쪽 하악부의 통증과 안면부 부종으로 개인병원에서 의뢰되었다. 왼쪽 하악골부터 관골까지 퍼진 안면부 부종을 보였으며 좌측 하악 유구치는 심한 충치가 없음에도 불구하고 중등도의 동요도를 보이고 타진에 양성 반응을 보였다. 방사선학적 소견으로는 좌측 하악 제2유구치와 제1영구치의 치조 백선 소실이 관찰 되었으며, 좌측 하악골에는 방사선 투과성의 골용해성 소견과 피질골의 파괴가 관찰되었다. 환아는 임상적, 방사선학적, 면역조직학적 검사를 바탕으로 Burkitt 림프종으로 진단되었고, 전신적인 검사와 항암 화학요법을 위해 본원 소아과로 의뢰되었다. 화학요법을 시작한 지 3개월만에 안면부 및 치은의 부종이 소실되었고, 치아의 동요도 및 위치도 정상으로 회복되었다. Burkitt 림프종으로 진단된 본 환아는 조기 진단과 집중적인 화학요법으로 좋은 예후를 보였기에 이를 보고하는 바이다.

• 대한소아치과학회지
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• 제36권2호
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• pp.298-304
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• 2009

X-linked hypophosphatemic rickets(이하 XLH로 기술)는 구루병의 일종으로 임상적으로는 비타민 D의 대량 투여로도 개선되지 않고 성염색체 우성 유전되는 유전성 질환이다. 저인산혈증성 구루병, 비타민 D저항성 구루병이라고도 불린다. 본 증례는 서울대학교병원 소아과에서 XLH로 진단받은 6세 6개월의 여아로, 상악 좌측 중절치의 매복을 주소로 소아치과에 의뢰된 환자이다. 환아는 XLH환자에서 전형적으로 보이는 보행 장애, 다리의 휨현상 작은 키, 손목, 무릎, 발목 관절의 종창 등이 관찰되었다. 또 치과적 특징으로 임상적으로 건전한 치아에서 자발적인 치근단 농양과 농루가 발생하였고 치아의 맹출 지연, 우상치 (taurodontism), 근단공의 폐쇄 지연, 확대된 치수강 등을 나타내었기에 이전 문헌 고찰을 통하여 XLH 환아의 특징을 살펴보고 본 환자의 의과적, 치과적 특성 및 매복된 치아의 치료에 대하여 보고하는 바이다.

• 한국농공학회지
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• 제8권1호
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• pp.1011-1034
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• 1966

This thesis is the final report which has long been studied by the author to obtain the design basis for various hydrological constructions with the specific system suitable to the natural environmental conditions in Korea. This report is divided into two parts: one is to estimate runoff volume from watersheds and the other to estimate the peak discharge for a single storm. According to the result of observed runoff record from watersheds, it is known that Kajiyama formula is useful instrument in estimating runoff volume from watersheds in this country. But it has been found that this formula shows us 20-30% less than the actual flow. Therefore, when wihed to bring a better result, the watershed characteristics coefficient in this formula, that is, f-value, should be corrected to 0.5-0.8. As for the method to estimate peak discharge from drainage basin, the author proposes to classify it in two ways; one is small size watershed and the other large size watershed. The maximum -flood discharge rate $Q_p$ and time to peak Pt obtained from the observed record on the small size watershed are compared by various methods and formulas which are based upon the modern hydrological knowledge. But it was fou.d that it. was not a satisfied result. Therefore, the author proposes. tocomputate $Q_p$, to present 4.0-5.0% for the total runoff volume ${\Sigma}Q$.${\Sigma}Q$ is computed under the assumption of 30mm 103s in watershed per day and to change the theoritical total flow volume to one hour dura tion total flow rate when design daily storm is given. Time to peak Pt is derived from three parameters which are u,w,k. These are computed by relationship between total runoff volume (ha-m unit)and $Q_p$. (C.M.S. unit). Finally, the author checked out these results obtained from 51 hydrographs and got a satisfied result. Therefore the author suggested the model of design dimensionless unit-hydrograph. And the author believes that this model will be much available at none runoff record river site. In the large size watersheds in Korea when the maximum discharge occurs, the effective rainfall is two consequtive stormy days. So the loss in watershed was assutned as 6Omm/2days,and the author proposed 3-hour-daration hydrograph flow distribution percentage. This distribution percentage will be sure to form the hydrograph coordinate.