• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.366-371
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• 2007

무선 센서 네트워크는 경제적, 환경적 목적으로 다양한 방면에서 활용되고 있다 이 때, 배치된 각 센서의 위치를 파악하는 것은 센서 네트워크에서 가장 기본적이며 가장 중요한 문제 중의 하나이다. 기존 논문에서 제안된 센서 위치 측정 방법은 특별한 장비를 장착하거나 특정한 환경의 지역에 한정시킨 방범으로 제한하고 있는 경우가 대부분이다. 하지만 어떠한 관심 지역의 환경은 언제라도 바뀔 수 있다. 또한, 센서가 위치할 환경의 기온, 풍속 등을 미리 안다는 것은 비현실적인 가정이다. 더구나 각각의 센서에 특별한 장비를 장착한다는 것은 비용 절감을 이유로 센서 네트워크를 운영하는 경우 오히려 그것을 이용하지 않는 경우보다 비용이 더 들 수도 있다. 이에 본 논문에서는 센서 노드의 기본적인 통신 기능은 이용하여, 환경에 순응적으로 센서의 위치를 측정할 수 있는 방법을 제안하고자 한다. 센서 노드에서 기본적으로 제공하는 통신 기능은 RF 전파를 보낼 때 전송 레벨을 달리하여 보낼 수 있다. 이러한 기본적인 기능을 이용하여 위치를 측정하게 되면 전체적인 센서 네트워크의 비용이 절감될 뿐만 아니라 환경에 순응적인 위치 측정이 가능하게 된다. 또한, 각 노드의 위치가 정해진 후 다른 노드와 통신할 때 전파의 세기를 조정함으로써 RF 통신에서 소모되는 전력량을 줄일 수 있다. 따라서 본 논문에서 제안하는 전송 레벨을 이용한 위치 측정 방법은 단순히 위치를 측정한다는 의미뿐 아니라 환경에 순응적으로 작동한다는 장점이 있다. 향후 네트워크 내에서 통신에 소비되는 전력을 줄일 수 있다는 점에서도 중요한 의미를 지닌다.를 집행하는 caspase의 활성 형태인 cleaved caspase-8, -9, -7, -3의 단백질 수준이 목향 헥산추출물의 처리에 의해 증가하였고 caspase-3의 표적 단백질 중 하나인 PARP의 불활성 형태인 cleaved PARP의 단백질 수준도 현저하게 증가하였다. 이 결과들은 목향 헥산 추출물이 LNCaP 세포의 apoptosis를 유도함으로써 전립선 암세포의 증식을 억제함을 보여주는 것이며 목향 헥산추출물에 의한 apoptosis 유도는 caspase 활성 증가와 Bak 및 t-Bid 단백질의 증가에 의한 것임을 제시한다. 따라서 앞으로 항암효과를 나타내는 성분의 동정 및 동물실험을 통하여 좀 더 면밀한 기전 연구가 수행된다면 목향 헥산추출물은 화학적 암예방 물질이나 치료제로 개발될 수 있을 것으로 사료된다.적 분해층과 마모질이가 가장 깊은 것으로 나타났으며 flowable type의 복합레진과 컴포머는 표면 경도와 마모도에서 양호한 결과를 보였다. 이상의 결과 복합레진과 컴포머의 평가요소로서 마모도와 함께 가수분해도 고려되어야 할 것으로 사료된다.증후군 환자에서 대조군에 비해 높은 비율을 보였다.er thinning은 3 군모두에서 관찰되었고 항암 3 일군이 가장 심하게 나타났다. 이상의 실험결과를 보면 술전 항암제투여가 초기에 시행한 경우에는 조직의 치유에 초기 5 일정도까지는 영향을 미치나 7 일이 지나면 정상범주로 회복함을 알수 있었고 실험결과 항암제 투여후 3 일째 피판 형성한 군에서 피판치유가 늦어진 것으로 관찰되어 인체에서 항암 투여후 수술시기는 인체면역계가 회복하는 시기를 3

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.4
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• pp.368-374
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• 2018

In this case, the patient was restored with gold Hader bar mandibular implant overdenture using two implants about 10 years ago, and the retentive force was lost due to severe wear of the bar due to 3.5 years use. The overdenture was repaired using a Locator attachment, but the male part was completely worn after 6.5 years use. Finally, we used a hybrid telescopic double crown with a friction pin to fabricate a new implant overdenture, which was observed for 2 years and showed excellent prognosis. So, we describe the cause of failure of each attachment (Gold Hader bar, Locator) in two implant overdentures and report on the advantages and disadvantages of double crown implant overdenture and the conditions for success.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.4
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• pp.401-406
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• 2016

Implant overdenture exhibits higher retention, masticatory function, and patient's satisfaction compared to conventional dentures. Particularly, in treatment of severe alveolar bone resorption, implant overdenture can be considered as the first treatment option. The types of attachments used for implant overdenture can be classified into solitary type, which implants are not connected to each other, and bar type in which implants are connected. In the case of solitary type commonly used in clinical practice, parallel relationship is important. When it is not established, there is a higher risk of attachment wear, retention loss, and frequent visits for maintenance. In this case, satisfactory results have been obtained with implant overdentures using milled bar on two unparallel implants placed on the mandible.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.305-310
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• 2012

It is a great challenge for dentists to do prosthetic restorations of a patient with reduced occlusal vertical dimension (OVD). Proper determination of the OVD is significant. An 85-year-old male patient came in with missing right maxillary posterior teeth. After diagnostic wax-up, reversible provisional prostheses were used to evaluate the new OVD in the maxilla and mandible. After that, the patient was evaluated clinically based on the criteria of esthetic, phonetic, and OVD. After 8 weeks, teeth with excessive wear were treated with root canal therapy and fiber post and core and irreversible provisional prostheses were done. After 8 weeks of observation period, final restorations with fixed partial dentures and removable partial dentures were made. Throughout the follow-up period of 6 months, no symptoms related with increased OVD and mechanical complications were observed.

• Journal of Conservation Science
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• v.25 no.4
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• pp.347-361
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• 2009

The Pohang Chilpori is the area with abundant petroglyphs in Korea. The form of the shield, female sex organs, and yut board on the outcrops or float rocks which are composed of the rhyolitic rock are engraved on Chilpori and Shinheungri Petroglyphs. The rhyolitic rock is composed of the phenocryst and groundmass with quartz and feldspar. The rock surface shows mostly yellowish brown color and the rock surface is very irregular by serious weathering, and illite and kaolinite, a kind of the clay minerals, are produced. Deterioration aspects are mainly of surface exfoliation, grain peel-off, damages, scribbling. Chilpori Petroglyph (1) plane has been eroded by running water, in (2) plane has been abrased is on the rock surface, in (3) plane shows surface exfoliation and the various part of the rock surface in plane (4) has become the soil. The corrasion and black phenomenon of the Shinheungri Petroglyph (1) plane was formed by running water, and surface exfoliation and scribbling in plane (2) is serious. Deterioration factors are geomorphologic states, plants, rock of weak to weathering, and artificial influence such as a scribbling and a forest fire. For conservation of the these petroglyphs, study for rock surface conservation and the arrangement of around petroglyphs and construction of water wall are necessary.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1991.11a
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• pp.34-37
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• 1991

Al계 베어링합금은 소착저항력등의 베어링특성이 우수하여 최근에 자동차의 엔진부품에 많이 사용되고 있다. Al계 베어링합금으로는 Al-Sn계, Al-Pb계, Al-Si계 합금이 개발되어 사용되어 왔다. Al-Si계 합금은 높은 강도, 우수한 부식성, 주조성이 향상되는 장점등을 갖고 있다. 또한 Al-Pb계 합금은 Pb가 고체윤활제로 작용하여 소착저항성이 높으며 가격도 저렴한 장점을 갖고 있다. Al과 Pb는 용융상태에서 넓은 용융간극을 갖어 중력편석을 일으키기 때문에 일반적인 주조방법으로 Al계 베어링합금을 제조할 수없다. 또한 Al에 Si이 첨가됨에 따라 높은 경도등의 기계적성질의 향상이 얻어지지만 Al 기지에 Si의 함량이 증가할 수록 편석이 심해져 조대한 Si-rich상이 미세조직에 존재하여 합금이 취약해지는 단점을 갖고 있다. 따라서 본 연구에서는 Al 기지에 Pb의 중력편석을 최소화하고 Al 기지에 조대한 Si-rich상이 생성되는 것을 막기 위하여 Al과 Pb가 공존하는 온도구역에서 높은 교반속도로 용탕을 강제교반하여 액상에서 Pb와 Si을 미세하게 분산시킨 후 수냉되는 동주형에서 급속응고시켜 Pb와 Si-rich 상이 균일하게 분포된 Al계 베어링합금을 제조하였다. 본 연구에서는 Pb의 양을 0%에서 35%까지 변화시켰으며, Si의 양을 0%에서 20%까지 변화시켜서 베어링합금을 제조하였으며, 강제교반속도는 500rpm에서 2500rpm 까지 변화시켜 베어링합금을 제조하였다.

• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.348-353
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• 2011

Iron fillings which were accumulated around the rail was often the cause of abnormal signal in case of signaling equipment using rail as transmission line. Iron fillings were generated on curved section of railroad due to the friction between rail and wheel, and metro line company urged to find the way to remove these iron fillings, because these were often the cause of abnormal signal. Magnetic device for trapping iron fillings around concrete slab tracks is introduced. The characteristics of magnetic device were analyzed using basic design and numerical analysis method. Magnetic device for trapping iron fillings were examined for application to the train which were operating in commercial line.

• Journal of Conservation Science
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• v.31 no.1
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• pp.37-46
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• 2015

In the case of adhesives & restoration agents currently being used for the preservation treatment of ceramics and earthenware, epoxy type, cellulose type and cellulose type are mainly being used. However, they are showing various problems such as re-detachment from severe contraction, color change from yellowing, work inconvenience of staining on tools and hand during usage and irreversibility. For the purpose of solving the issues of yellowing and irreversibility of epoxy resin being used to restore ceramics, urethane synthetic resin with low yellowing excellent reversibility has been developed in this study. The adhesive strength of urethane resin that has been developed has excellent properties with 2.07MPa for undiluted solution, which is 1.5 times higher than that of existing material EPO-$TEK301^{(R)}$ 1.21MPa. The result of workability measurement showed that the wear rate of urethane resin (in Talc 50wt%) was 1.09%, which was somewhat higher than that of existing material Quick $Wood^{(R)}$ (1.02%). In addition, its wear rate is two times higher than that of $EPO-TEK301^{(R)}$ (0.41%) and $L30^{(R)}$ (0.39%), thereby showing an advantage in its forming process compared to existing materials. As for the advantage of urethane resin of reversibility experiment, 12 hours after acetone, ethyl alcohol deposition, urethane resin and filler talc were dissolved 100% while showing powdering phenomenon. Compared to 0% reversibility of existing epoxy resin, it has much superior reversibility. The result of UV rays experiment to evaluate its durability showed that ${\Delta}E^*ab$ color change value based on undiluted solution of urethane resin was 2.76 before & after UV rays exposure, which was a decrease by about 7-20 times compared to that of existing resin, thereby minimizing the issue of heterogeneity.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.64-71
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• 2010

Purpose: To evaluate pathologic patterns and outcomes of treatment of a biceps tendon lesion associated with a rotator cuff tear. Materials and Methods: We reviewed 92 patients (i) who underwent surgery for a cuff tear, (ii) for whom the biceps lesion could be observed retrospectively, and (iii) had a minimum follow-up of 2 years. The pathology of biceps tendon was classified into 4 types: tenosynovitis, fraying or hypertrophy, tear, and instability. All but the 4 with massive cuff tears were repaired. The biceps lesions were treated with debridement in 30, tenotomy in 10, tenodesis in 8, and recentering in 4. UCLA scoring was used for clinical results. Results: Seventy patients had a biceps lesion, 19 tenosynovitis, 22 fraying or hypertrophy, 21 a tear, and 8 instability. A biceps lesion was observed in 63% of cases of cuff tears below the medium size, and in 88% of cases with cuff tears above the large size. UCLA scores according to the pathology of the biceps lesion were 29.6 in the absence of a biceps lesion, and 28.3 in its presence. UCLA scores in patients with tenotomy or tenodesis for associated biceps tendon lesions were 28.2. Conclusion: There is a greater incidence and severity of a biceps lesion with a larger cuff tear. Therefore, the cause of a biceps lesion might be related to the cause of the cuff tear. Among the several options of treatment for biceps lesion, tenotomy or tenodesis may be particularly effective in providing pain relief.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.140-145
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• 2024

Removable partial denture wearers are exposed to the risks that remaining teeth get damaged by caries, attritions, erosion, and fracture. In the case of damaged abutment tooth which should fit to Removable partial denture (RPD), the fabrication of surveyed crown is followed by the making of RPD. However, making new denture takes a long time, and needs several processes and costs. Also, patients should get used to new denture. If other abutment teeth and edentulous ridges provide the existing denture with support, retention, and stability, use of existing denture is considered clinically acceptable. In this situation, fabricating retrofit crowns to an existing removable partial denture makes patient use existing denture, cuts costs, and reduces discomfort. In this case, severely worn teeth were restored using monolithic zirconia crown which fit to an existing removable partial denture by CAD-CAM. Moreover, support, retention, and stability of the denture were improved, and both doctor and patient were satisfied with the result.