http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lee, Jeong-Keun,Lee, In-Beum,Han, Jeehoon Elsevier 2019 Journal of industrial and engineering chemistry Vol.75 No.-
<P><B>Abstract</B></P> <P>This paper presents a study of the techno-economic analysis of producing methanol (MeOH) from steel mill off-gases, especially coke oven gas and basic oxygen furnace gas. The mixed off-gases produce syngas with appropriate H<SUB>2</SUB>/CO ratio and are converted to MeOH. A detailed kinetic model over a commercial catalyst Cu/ZnO/Al<SUB>2</SUB>O<SUB>3</SUB> is applied for MeOH synthesis reaction. Four process designs were analyzed; they are combinations of two syngas compositions and the presence or absence of an interim MeOH-separation unit. When production rate was 22.2–28.3 t MeOH h<SUP>−1</SUP>, the unreacted purged gas could be used to generate electricity or can be sold as a fuel. The energy efficiency was in the range of 54.6–55.9%, considering both MeOH and electricity as an energy output. A heat-exchanger network is designed to minimize energy usage in the process. We analyzed the proposed process techno-economically and calculated a minimum selling price. The best case gives $0.57 kg<SUP>−1</SUP> which is slightly higher than the recent market price, although a sensitivity analysis suggests that the price can be decreased in some cases. This study can be a basis for further research on this process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A techno-economic analysis is conducted for methanol production from steel-work off-gases. </LI> <LI> Kinetic model over a catalyst Cu/ZnO/Al<SUB>2</SUB>O<SUB>3</SUB> is considered for methanol synthesis. </LI> <LI> Process cases with different feed composition and separation scheme are designed. </LI> <LI> Energy and time-considering economic feasibility are analyzed for the cases. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Jeehoon Lee,Minjoong Rim,Kiseon Kim IEEE 2016 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY Vol.65 No.4
<P>Analog network coding (ANC) is an effective scheme for increasing network throughput by simultaneously transmitting packets from sources to a relay and amplifying and forwarding the superposition of the packets from the relay to the corresponding destinations. The ANC scheme theoretically reduces half of the required transmission phases in cooperative relaying networks, including two source-destination pairs and a single relay. Such an advantage can be obtained only when the impact of the quality of overhearing links (OLs) on the decoding results of the desired signals at the targeted destinations is negligible. However, in practical wireless environments, the network throughput of the ANC scheme may not be doubled and may be even worse than that of a conventional amplify-and-forward (AF) relaying scheme due to poor channel quality of the OLs. In this paper, we investigate the impact of the channel quality of OLs on the power allocation strategy and relay location to improve the sum rate.</P>
On the Outage Performance of Selection Amplify-and-Forward Relaying Scheme
Jeehoon Lee,Minjoong Rim,Kiseon Kim IEEE 2014 IEEE communications letters Vol.18 No.3
<P>In this letter, we propose a selection amplify-and-forward (AF) relaying scheme which has the lower outage probability than that of a conventional AF relaying scheme in cooperative relay networks. In real wireless environments, as the channel of source-to-destination (SD) link varies with an increase in time, we can also obtain a diversity gain through the SD link by retransmission in common with a conventional AF relaying scheme. Thus, we can expect a performance enhancement by adaptively determining the transmitting node between the relaying and source nodes. We propose a method for adaptively determining between AF relaying and retransmission schemes, and show that the additional diversity gain can be obtained by the proposed scheme.</P>
Lee Kyu-Sun,Kim Jae-hyoung,Kang Jeehoon,Cho Hyun-Jai,Lee Hae-Young 대한의학회 2023 Journal of Korean medical science Vol.38 No.35
Background: Volume overload is associated not only with clinical manifestations but also with poor outcomes of heart failure (HF). However, there is an unmet need for effective methods for serial monitoring of volume status during HF hospitalization. The aim of this study was to evaluate the prognostic implication of serial measurement of bioelectrical impedance analysis (BIA) in patients hospitalized with acute HF. Methods: This study is a retrospective observational study and screened 310 patients hospitalized due to acute decompensated HF between November 2021 and September 2022. Among them, 116 patients with acute HF who underwent BIA at the time of admission and at discharge were evaluated. We investigated the correlation between change of BIA parameters and the primary composite outcome (in-hospital mortality or rehospitalization for worsening HF within one month). Results: The median (interquartile range) age was 77 years (67–82 years). The mean left ventricular ejection fraction was 40.7 ± 14.6% and 55.8% of HF patients have HF with reduced ejection fraction. The body water composition (intracellular water [ICW], extracellular water [ECW], and total body water [TBW]) showed a statistically significant correlation with body mass index and LV chamber sizes. Furthermore, the ratio of ECW to TBW (ECW/TBW), as an edema index showed a significant correlation with natriuretic peptide levels. Notably, the change of the edema index during hospitalization (ΔECW/TBW) showed a significant correlation with the primary outcome. The area under the curve of ΔECW/TBW for predicting primary outcome was 0.71 (95% confidence interval [CI], 0.61–0.79; P = 0.006). When patients were divided into two groups based on the median value of ΔECW/TBW, the group of high and positive ΔECW/TBW (+0.3% to +5.1%) had a significantly higher risk of the primary outcome (23.2% vs. 8.3%, adjusted odds ratio, 4.8; 95% CI, 1.2–19.3; P = 0.029) than those with a low and negative ΔECW/TBW (−5.3% to +0.2%). Conclusion: BIA is a noninvasive and effective method to evaluate the volume status during the hospitalization of HF patients. The high and positive value of ΔECW/TBW during hospitalization was associated with poor outcomes in patients with HF.
Lee, Suh-Young,Lee, Jae-Uk,Lee, In-Beum,Han, Jeehoon Elsevier 2017 APPLIED ENERGY Vol.189 No.-
<P>We present a stochastic decision-making algorithm for the design and operation of a carbon capture and storage (CCS) network; the algorithm incorporates the decision-maker's tolerance of risk caused by uncertainties. Given a set of available resources to capture, store, and transport CO2, the algorithm provides an optimal plan of the CCS infrastructure and a CCS assessment method, while minimizing annual cost, environmental impact, and risk under uncertainties. The model uses the concept of downside risk to explicitly incorporate the trade-off between risk and either economic or environmental objectives at the decision-making level. A two-phase-two-stage stochastic multi-objective optimization problem (2P2SSMOOP) solving approach is implemented to consider uncertainty, and the s-constraint method is used to evaluate the interaction between total annual cost with financial risk and an Eco-indicator 99 score with environmental risk. The environmental impact is measured by Life Cycle Assessment (LCA) considering all contributions made by operation and installation of a CCS infrastructure. A case study of power-plant CO2 emission in Korea is presented to illustrate the application of the proposed modeling and solution method. (C) 2016 Elsevier Ltd. All rights reserved.</P>
온라인 커뮤니티에서 유저의 사회성을 고려한 유저 랭킹 : 온라인 커뮤니티 유저의 스코어에 따른 랭킹에서 사회성을 고려한 유저의 랭킹
이지훈(Jeehoon Lee),황규현(Kyouhyun Hwang),신효섭(Hyoseop Shin) 한국HCI학회 2010 한국HCI학회 학술대회 Vol.2010 No.1
In online communities or blogospheres, the users publish their posts on their own space, and then their posts get feedback actions from other users in the form of a comment, a trackback or a recommendation. These interactions form social relationships between users. Thus, the problem of users' rankings can be approached in terms of the analysis of the social relationships between users. PageRank have often been applied for users' rankings, especially for users' reputation, but there has been no consideration of the fact that the users' sociability can affect the user's reputation. To address this problem, in this paper, we newly propose two different factors that affect the score of every user: the user's reputation and the sociability. Furthermore, we present novel schemes that effectively and separately can measure the reputation and the sociability of the users in online communities. And we prove our results by experiments and user studies. 온라인 커뮤니티와 블로그 상에서 유저들은 자신만의 공간에 글(이하 포스트)을 개제하고 다른 유저들이 작성한 포스트에 코멘트나 트랙백, 추천 등으로 피드백을 주기도 한다. 이러한 유저들간의 상호 활동은 사회적 관계를 형성하게 되고, 이 관계를 분석 함으로써 유저를 랭킹 할 수 있게 된다. 대표적인 유저 랭킹 방법으로는 PageRank 가 있다. 그러나 이 방법은 유저들간의 사회성이 각 유저의 평판도에 영향을 미칠 것이라는 것을 간과 하고 있다. 그래서 이번 논문에서는 유저의 스코어에 영향을 줄 수 있는 것으로 평판도와 사회성을 정의하고 각각에 대한 효과적인 계산 방법을 제시한다. 그리고 실험결과와 유저 스터디를 통해 우리의 새로운 제안이 얼마나 효율적인지를 알아 본다.