이젝터 구동관로의 유동특성 연구

설재림,오정교,고현선,장현준 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.1

이젝터(Ejector)의 원리는 노즐에서 높은 유속을 갖고 분출하는 유체의 운동에너지에 의하여 저에너지 유체를 흡입하는 펌프의 일종이다. 이젝터는 생산현장의 열기관이나 유체기계발전소의 대류열전달 및 공기조화 덕트시스템에는 필연적으로 관로망이 연결되며 이들 관로망의 설계는 플렌트 전체의 효율뿐만 아니라 안정성과도 밀접한 관계를 갖고 있다. An ejector IS a fluid-transportation device, which spouts high-pressure fluid from driving pipes using kinetic energy of spouted fluid and raises pressure through exchange of momentum with surrounding gases of lower pressure. It can be manufactured with a simple structure irregardless of size of system, installed and used easily at places where fluid is flowing.

두경부 암환자의 항암화학요법에 따른 삶의 질 변화

신혜숙,박혜자,박명희,연기순,김훈교,문한림,송혜향 가톨릭대학교 가톨릭대학교 간호대학 호스피스 교육연구소 1999 호스피스논집 Vol.4 No.-

The purpose of this study was to assess the changes in quality of life wish elapse of chemotherapy in head and neck cancer patients. This study was a longitudinal descriptive design. The subjects were 9 patients who had stage III and stage IV head and neck cancer and received neoadjuvant cisplatin and 5-fluorouracil chemotherapy. Linear Analogue Self Assessment Scale (LASA) of the QOL which it includes eleven items(seven physical items appetite, nausea/vomiting, physical well-being, vigor activity, energy, sleepiness, fatigue and four mental items anger, anxiety, depression & vital power) were used to assess the quality of life eleven times(once in the prechemotherapy period and from the 1st day to 10th day postchemotherapy). The means of scores at each time were analyzed by repealed measures of ANOVA and Bonferroni multiple comparison method. The results are as follows : 1. The degree of appetites decreased significantly on the period between third and sixth day compared with that of appetites on the prechemotherapy day (p<0.001). 2. The degree of physical well-being decreased significantly on the period between first and fifth day compared with that of physical well-being on the prechemotherapy day (p<0.001). 3. The degree of nausea/vomiting decreased significantly on the period between first and fourth day compared with that of appetites on the prechemotherapy day (p<0.001). 4. The degree of anger decreased significantly on the second, fourth, eighth and ninth day after chemotherapy compared with that of anger on the prechemotherapy day(p<0.001). 5. The degree of fatigue decreased significantly on the fourth day compared with that of fatigue on the prechemotherapy day(p<0.001). 6. The increment of nausea/vomiting and poor appetite started on the 2.89th day and 3.67th day after chemotherapy, respectively. 7. The increment of sleepiness started on the 2.56th day after chemotherapy. 8. The increment of depression and anxiety started on the 2.33th day and 3.33th day after chemotherapy, respectively. 9. The lowest degrees of nausea/vomiting and poor appetite were 37.00±17.9 % and 28.64±14.94 % after chemotherapy compared with those of nausea/vomiting and poor appetite on the prechemotherapy day, respectively. 10. The lowest degrees of anger and vigor activity were 48.12±28.3 % and 39.83±24.9 % after chemotherapy compared with those of anger and vigor activity on the prechemotherapy day, respectively. 11. The recovery rates of eight items of quality of life (appetite, vigor activity, energy, fatigue, anger, anxiety, depression & vital power) were shown to reach a peak on the tenth day after chemotherapy and be reached to almost 84 % compared with those of quality of life on the prechemotherapy day. 12. The recovery rates of physical well-being and sleepiness were shown to reach to 67.75 % and 95.68 % on the 10th day after chemotherapy compared with those of physical well-belong and sleepiness on the prechemotherapy day. 13. The recovery rates of seven physical items were faster than those of four mental items on the 10th day after chemotherapy. In conclusion, it is suggested that nursing care strategies to improve the quality of life in patients with chemotherapy would be established both physically and mentally, and be extended at least ten days when patients stayed their home after chemotherapy.

Reinforcement learning-based virtual network embedding: A comprehensive survey

Lim Hyun-Kyo,Ullah Ihsan,Han Youn-Hee,Kim Sang-Youn 한국통신학회 2023 ICT Express Vol.9 No.5

Virtual network embedding plays a vital role in network virtualization, as it determines the deployment and connection of virtual networks to the physical network in the 5G and beyond. An efficient virtual network embedding algorithm is essential to ensure that virtual networks are embedded in a way that meets the performance, security, and resource requirements of the virtual networks and their users. The integration of reinforcement learning with virtual network embedding can lead to more intelligent and efficient network management, which can enhance the performance of large-scale networked systems. Reinforcement learning has the potential to improve and overcome some limitations of traditional algorithms, such as the need for prior knowledge of network conditions and the difficulty in dealing with non-linear and dynamic network environments. Therefore, we conducted this survey to provide a comprehensive overview and examine potential future directions for the optimal reinforcement learning-based virtual network embedding solutions. However, applying reinforcement learning directly to virtual network embedding is a challenging task that requires further research and study. Additionally, it encourages researchers to examine the potential of reinforcement learning in virtual network embedding, identify the challenges for its application, and cover various factors related to the reinforcement learning application in virtual network embedding, including motivations, performance metrics, and challenges.

Anemia after gastrectomy for early gastric cancer: long-term follow-up observational study.

Lim, Chul-Hyun,Kim, Sang Woo,Kim, Won Chul,Kim, Jin Soo,Cho, Yu Kyung,Park, Jae Myung,Lee, In Seok,Choi, Myung-Gyu,Song, Kyo-Young,Jeon, Hae Myung,Park, Cho-Hyun WJG Press 2012 WORLD JOURNAL OF GASTROENTEROLOGY Vol.18 No.42

<P>To identify the incidence and etiology of anemia after gastrectomy in patients with long-term follow-up after gastrectomy for early gastric cancer.</P>

Experimental Research Article : Native Low-density Lipoprotein-induced superoxide anion contributes to proliferation of human aortic smooth muscle cells

Hyun Kyo Lim,Woo Sung Shin,Ji Yeon Lee,Sung Woo Ryoo 대한마취과학회 2009 Korean Journal of Anesthesiology Vol.57 No.5

Background: Native low-density lipoprotein (nLDL) was one of the modifiable risk factors contributed directly to cardiovascular diseases development. We investigated that nLDL stimulation induced NADPH oxidase activation and superoxide production that was an important factor on human aortic smooth muscle cells (hAoSMC) proliferation. Methods: Superoxide generation was recorded with fluorescent-staining of dihydroethidine or by measuring lucigenin-induced chemiluminescence for 5 minutes. We examined cell proliferation with 4[-3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1, 3-benzene disulfonate (WST-1) reagent and analyzed the change of gene expression by northern blot analysis. Results: nLDL stimulation increased superoxide anion production in hAoSMC that confirmed through dihydroethidine staining and lucigenin-induced chemiluminescence methods. nLDL-induced proliferation abolished with preincubation of superoxide scavengers or NADPH oxidase inhibitor. NADPH as a substrate of NADPH oxidase increased superoxide generation in both nLDL-stimulated and unstimulated cell homogenate, which was completely blocked at the diphenylene iodinium (DPI)- or apocynin-pretreated hAoSMC homogenates. Furthermore, superoxide generation was only observed at the fraction of cellular precipitate, but not in soluble fraction. Expression of p22phox in mRNA level increased with nLDL treatment as early as 30 minutes and transfection of anti-sense oligonucleotide of p22phox completely abolished nLDL-induced proliferation of hAoSMC. Conclusions: The above results have shown that nLDL-induced proliferation in hAoSMC depends on superoxide production through NADPH oxidase activation. (Korean J Anesthesiol 2009;57:622∼8)

Ego Network 기반 가상 네트워크 임베딩 기법

임현교(Hyun-Kyo Lim),울라 이산(Ullah Ihsan),허주성(Joo-Seong Heo),한연희(Youn-Hee Han) 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.2

최근 5G 네트워크가 상용화됨에 따라, 다양한 서비스들이 존재하며, 각 서비스의 요구사항을 만족시키기 위하여 효과적이고 유연한 네트워크 관리 기술을 요구한다. 이를 위하여, 네트워크 가상화 기술은 물리적 네트워크를 하나 이상의 소프트웨어 기반 가상 네트워크로 만들어 각 서비스의 요구사항에 적합한 네트워크 자원을 제공한다. 그러나 네트워크 자원을 효율적으로 제공하기 위해, 가상 네트워크를 물리적 네트워크로 임베딩할 수 있는 가상 네트워크 임베딩 알고리즘이 필요하다. 본 논문에서는 가상 네트워크의 노드 및 링크의 임베딩 성능을 향상시키기 위해 Ego Network 기반 가상 네트워크 임베딩 알고리즘을 제안한다. 더 나은 링크 임베딩을 위해 노드의 반경으로 기준 노드의 홉 수를 사용해 Ego Network를 구성한 후, 홉 수 측면에서 서로 가까운 물리적 노드를 선택해 가상 노드에 임베딩 시킨다. 제안된 방식은 노드 및 링크의 관계를 Ego Network를 통해 고려함으로써 가상 네트워크 요청의 수락 비율을 증가시킨다. 제안하는 Ego Network 기반 가상 네트워크 임베딩 알고리즘의 검증을 위하여 본 논문에서는 기존의 알고리즘들과 비교 검증한다.

양자암호통신망에서 양자키 자원 효율적 활용을 위한 라우팅 방법 연구

임현교(Hyun-Kyo Lim),이찬균(Chankyun Lee),이원혁(Wonhyuk Lee),한연희(Youn-Hee Han) 한국통신학회 2024 한국통신학회 학술대회논문집 Vol.2024 No.1

분산 다중 에이전트 기반 연합 강화 학습을 활용한 학습 성능 개선

임현교(Hyun-Kyo Lim),김주봉(Ju-Bong Kim),한연희(Youn-Hee Han) 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.11

Convolution Neural Network 와 Recurrent Neural Network 를 활용한 네트워크 패킷 분류

임현교 ( Hyun-kyo Lim ),김주봉 ( Ju-bong Kim ),한연희 ( Youn-hee Han ) 한국정보처리학회 2018 한국정보처리학회 학술대회논문집 Vol.25 No.1

최근 네트워크 상에 새롭고 다양한 어플리케이션들이 생겨나면서 이에 따른 적절한 어플리케이션별 서비스 제공을 위한 패킷 분류 방법이 요구되고 있다. 이로 인하여 딥 러닝 기술이 발전 하면 서 이를 이용한 네트워크 트래픽 분류 방법들이 제안되고 있다. 따라서,본 논문에서는 접 러닝 기 술 중 Convolution Neural Network 와 Recurrent Neural Network 를 동시에 활용 한 네트워크 패킷 분류 방법을 제안한다.

이동성 관리를 위한 SDN 기반 LTE/EPC 네트워크 모델 제안 및 실험

임현교 ( Hyun-kyo Lim ),허주성 ( Joo-seong Heo ),김주봉 ( Ju-bong Kim ),한연희 ( Youn-hee Han ) 한국정보처리학회 2017 한국정보처리학회 학술대회논문집 Vol.24 No.1

최근 급격히 증가한 모바일 기기와 Over The Top (OTT) 서비스의 활성화로 인하여 CMM 기반의 LTE/EPC 네트워크에 과다한 데이터/제어 트래픽의 수용이 힘들어지는 문제가 중요 이슈로 부각되고 있다. 이를 해결하기 위하여 IETF는 Distributed Mobility Management (DMM) 기반의 이동성 관리 방안을 제안하였다. 하지만 DMM 기술은 중앙의 트래픽 부하 분산에 초점을 두고 있어 단말의 이동과 관련하여 발생하는 과다한 제어 트래픽 수용에 관한 문제를 해결하기에는 부족하다. 따라서 본 논문에서는 이러한 문제를 해결하기 위하여 SDN 기반으로 CMM과 DMM을 함께 이용하는 HMM (Hybrid Mobility Management) LTE/ECP 네트워크 모델을 제시한다. 또한 HMM 기반의 LTE/EPC 네트워크 모델은 CMM 및 DMM 기법의 선택을 위해 단말의 이동성과 PDN 연결의 개수를 고려한 선택방안을 제시하며, 제안하는 HMM 기반의 LTE/EPC 네트워크 구조에서의 데이터 트래픽 부하량과 단말의 이동성과 PDN 연결 개수에 따라 제어 트래픽의 양을 비교하는 그래프를 제시하며 제안하는 네트워크 모델의 타당성을 입증한다.