• Design & Manufacturing
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• 제8권1호
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• pp.27-30
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• 2014

Alloy tool steel such as SKD11 and SKD61 or high speed tool like SKH51 are used as materials for semiconductor dies. Cavities, curl blocks, pot blocks and housings are made from those materials. To make those parts from alloy tool steel or high speed tool, one utilizes discharge machining, and mechanical machining including machining center, milling, drilling, forming grinding and others. In the process of cutting machining and polishing, the die materials become unsuitable for machining owing to bubbles and foreign substances in them, which hinders production process. Therefore, this study focuses on die material selection criteria, and on analysis and comparison of material characteristics to help companies to solve their problems, make die manufacture less burdensome and extend die life.

• 한국해양학회지
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• 제30권1호
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• pp.57-63
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• 1995

$\beta$-효과를 포함한 원통 용기 내의 상하층유체의 하충운동을 하충수와 같은 밀도를 갖는 외부유체를 주입하여 야기시키고 상층수와 같은 유체를 유입 및 유출시켜 지형류 조절에 의한 경계면의 변형 및 이에 따른 상층운동 특성을 실험적으로 관찰하였다. 특 히 유입-유출 위치를 변경시키고 동시에 유입과 유출양을 다르게 하여 상층수에 해상 풍의 효과를 첨가하였다. 실험의 목적은 극전선 형성과 관련하여 유입-유출 경로(대만 난류의 유입-쓰가루, 쏘야 유출)를 결정짓는 외부 인자를 파악하고자 함이다. 유입, 유출양이 같은 경우 유입수의 경로는 서안에 따라 북상하다가 이안후 위도에 평행하게 유출된 반면 상층수에 해상풍의 영향을 주었을시 서안 경계류의 분기(negative curl of wind stress 효과시), 남향의 서안 경계류에 의한 유입수의 내부로 침투(positive curl of wind stress 효과시) 등의 현상을 보여준다. 한편 유입-유출의 위치를 변경 시켜 유입수의 위치를 서안경계에 두었을 시 유입수의 경로가 경계면의 지형류 조절에 의한 서안에 근접하게 북상후 유출 (negative curl), 동안에 근접하게 북상후 유출 (positive curl)의 특성을 보여준다. 북부의 반시계방향의 흐름이 유입수의 북방 한계 를 결정짓는 역할을 하고 있음도 관찰되었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3050-3065
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• 2016

Neural networks (NNs) are extensively used in applications requiring signal classification and regression analysis. In this paper, a NN based threshold selection algorithm for 60 GHz millimeter wave (MMW) time of arrival (TOA) estimation using an energy detector (ED) is proposed which is based on the skewness, kurtosis, and curl of the received energy block values. The best normalized threshold for a given signal-to-noise ratio (SNR) is determined, and the influence of the integration period and channel on the performance is investigated. Results are presented which show that the proposed NN based algorithm provides superior precision and better robustness than other ED based algorithms over a wide range of SNR values. Further, it is independent of the integration period and channel model.

• Clinics in Shoulder and Elbow
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• 제23권4호
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• pp.169-177
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• 2020

Background: We evaluated the need for arthroscopic capsular release (ACR) in refractory primary frozen shoulder (FS) by comparing clinical outcomes of patients treated with ACR and manipulation under anesthesia (MUA). Methods: We assessed patients with refractory primary FS, 57 patients (group A) who were treated with MUA and 22 patients (group B) who were treated with ACR. In group A, manipulation including a backside arm-curl maneuver was performed under interscalene brachial block. In group B, manipulation was performed only to release the inferior capsule before arthroscopic circumferential capsular release, which was carried out for the unreleased capsule after manipulation. Pain, range of shoulder motion, and American Shoulder and Elbow Surgeons score were recorded at 1 week, 3 months, 6 months, and 1 year after surgery. We compared outcome variables between treatment groups and between diabetics and non-diabetics and also evaluated the numbers of patients receiving additional intra-articular steroid injection. Results: Outcome variables at 3 months after surgery and improvements in outcome variables did not differ between groups. Group A showed significantly better results than group B in the evaluation of pain and range of motion at 1 week. Diabetics showed comparable outcomes to non-diabetics for most variables. Eleven patients required additional steroid injections between 8 to 16 weeks after surgery: 12.2% in group A, 18.2% in group B. Additional injections were given three times more often in diabetics compared to non-diabetics. Conclusions: MUA alone can yield similar clinical outcomes to ACR in refractory FS.