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복합곡면 가공시 공구간섭의 탐지와 공구경로 수정에 관한 연구
서태일,조명우,조재형 한국공작기계학회 1999 한국생산제조학회지 Vol.8 No.6
In this paper we deal with interference problem in the case of compound surface machining. A new tool interference detection and correction method based on the envelope of the tool path is suggested to identify and correct the tool interference - not only within the local path of tool movement, but also outside of the tool path. Therefore, the developed strategy can be used to check the possible interference in any region of the surface. In order to analyze quantitatively the milled surface errors produced by the tool interference, improved surface prediction model is also suggested in cutting process by general cutters. The effectiveness of th proposed method is demonstrated through simulation study.
Jae Won Seo,Kyu Seong Park,Gwang Bin Lee,Sang-eun Park,Jae-Hoon Choi,Myeong Hee Moon 대한면역학회 2023 Immune Network Vol.23 No.4
Lipid accumulation in macrophages is a prominent phenomenon observed in atherosclerosis. Previously, intimal foamy macrophages (FM) showed decreased inflammatory gene expression compared to intimal non-foamy macrophages (NFM). Since reprogramming of lipid metabolism in macrophages affects immunological functions, lipid profiling of intimal macrophages appears to be important for understanding the phenotypic changes of macrophages in atherosclerotic lesions. While lipidomic analysis has been performed in atherosclerotic aortic tissues and cultured macrophages, direct lipid profiling has not been performed in primary aortic macrophages from atherosclerotic aortas. We utilized nanoflow ultrahigh-performance liquid chromatography-tandem mass spectrometry to provide comprehensive lipid profiles of intimal non-foamy and foamy macrophages and adventitial macrophages from Ldlr−/− mouse aortas. We also analyzed the gene expression of each macrophage type related to lipid metabolism. FM showed increased levels of fatty acids, cholesterol esters, phosphatidylcholine, lysophosphatidylcholine, phosphatidylinositol, and sphingomyelin. However, phosphatidylethanolamine, phosphatidic acid, and ceramide levels were decreased in FM compared to those in NFM. Interestingly, FM showed decreased triacylglycerol (TG) levels. Expressions of lipolysis-related genes including Pnpla2 and Lpl were markedly increased but expressions of Lpin2 and Dgat1 related to TG synthesis were decreased in FM. Analysis of transcriptome and lipidome data revealed differences in the regulation of each lipid metabolic pathway in aortic macrophages. These comprehensive lipidomic data could clarify the phenotypes of macrophages in the atherosclerotic aorta.
A Quadrature Error Corrector for Aperiodic, Quarterrate Data Strobe Signals in HBM3 Interfaces
Seo-Yeong Jo,Jaeha Kim,Deog-Kyoon Jeong,Jinhyung Lee,Myeong-Jae Park 대한전자공학회 2022 Journal of semiconductor technology and science Vol.22 No.3
This paper proposes a quadrature error corrector (QEC) for the aperiodic, quarter-rate data strobe (DQS) signals in the high bandwidth memory generation 3 (HBM3) interfaces. Unlike the existing approaches, which are applicable to periodic clock signals only, the proposed QEC can adjust the phase spacings among four aperiodic, quarter-rate DQS signals to be equal to 1/4 of the operating clock period. Its pulse-width detector measures each phase spacing by charging a capacitor with a fixed current during the difference period and comparing its voltage against the voltage of a four-times larger capacitor charged for the whole clock period. The post-layout simulation results of a prototype QEC designed in a 40-nm CMOS process show that the QEC can correct the phase errors ranging -43.2~43.2° with errors less than 5.01° for both seamless and burst modes. The QEC consumes the maximum power of 2.42mW when operating at 1.6-GHz and 1.1-V supply, and occupies the active area of 0.01 mm2.
Seo-Eun Cho,Joo Hyun Jung,Jae Myeong Kang,Min Young Cho,Yea Seol Lee,Seung-Gul Kang,Seon Tae Kim 대한신경정신의학회 2024 PSYCHIATRY INVESTIGATION Vol.21 No.2
Objective Continuous positive airway pressure (CPAP) is the preferred treatment for obstructive sleep apnea (OSA). However, compliance with CPAP therapy varies among studies, and studies on its predictors are insufficient in Korea. This study aimed to identify factors that predict compliance with CPAP therapy in patients with OSA.Methods We retrospectively reviewed medical records, polysomnography (PSG) records, and self-report questionnaires of patients w ith OSA. Criteria for compliance was the use of CPAP devices for ≥4 h per night for ≥70% of the consecutive 30 nights (i.e., 21 days) during the first 3 months of treatment initiation. The patients were classified into two groups: compliant and non-compliant. Logistic regression analyses were performed to identify the clinical factors and PSG parameters associated with CPAP compliance.Results Of the 188 participants, 80 were classified into the compliant group and 108 into the non-compliant group. The ratios of stage N1 (p=0.011) and health insurance coverage (p=0.007) were significantly associated with compliance with CPAP, with an explanatory power of 18.6% (R<sup>2</sup>=0.186, p<0.001).Conclusion Stage N1 ratio and health insurance coverage were significant predictors of CPAP compliance. It is necessary to confirm whether the relationship between a high stage N1 ratio and compliance can be reproduced in a larger sample and in individuals from other countries.
Protective Effecf of Brazilin on Cisplatin Nephrotoxicity
Seo, Kyung Won,Kong, Jae Myeong,Choung, Se Young 한국응용약물학회 1994 Biomolecules & Therapeutics(구 응용약물학회지) Vol.2 No.2
Cisplatin is one of the most effective antitumor agents currently available for cancer therapy. However, its clinical use has been limited by its severe side effects, especially nephrotoxicity. Therefore, brazilin, which has a radical scavenging effect, was given intraperitoneally to evaluate the effect on cisplatin nephrotoxicity in rats. Remarkable protective effects against nephrotoxicity of cisplatin were observed when brazilin was administered to rats simultaneously with cisplatin. Hepatotoxicity induced by combination treatment of cisplatin and brazilin was evaluated by measuring serum glutamic pyruvate transaminase and serum glutamic oxalate transaminase. Combination treatment did not affect the levels of sGPT and sGOT, and any combination treatment did not induce metallothionein in kidney. Brazilin which has radical scavenging effect directly reduced nephrotoxicity of cisplatin in vivo. Thus, it seems that nephrotoxicity of cisplatin was caused by free radicals. The present results indicate that brazilin, when it is given with cisplatin, may provide protection against cisplatin nephrotoxicity in rats.