Efficient Macro Mobility Management for GPRS IP Networks

Choi, Seong-Gon,Mukhtar, Rami,Choi, Jun-Kyun,Zukerman, Moshe The Korea Institute of Information and Commucation 2003 Journal of communications and networks Vol.5 No.1

Mobile IP has several inefficiencies, and was not originally designed for situations where both peers are highly mobile. We present a mobility management solution that retains compatibility with existing Internet protocols, whilst increasing the efficiency of communications between two GPRS mobile hosts. Our proposal eradicates triangle routing and minimizes handover latency. We show by numerical analysis that the routing optimization improves the performance of TCP controlled data flows, reducing buffering requirements and minimizing the recovery time after a handover occurs.

Emerging evidence that ginseng components improve cognition in subjective memory impairment, mild cognitive impairment, and early Alzheimer’s disease dementia

Rami Lee,Ji-Hun Kim,Won-Woo Kim,Sung-Hee Hwang,Sun-Hye Choi,Jong-Hoon Kim,Ik-Hyun Cho,Manho Kim,Seung-Yeol Nah 고려인삼학회 2024 Journal of Ginseng Research Vol.48 No.3

Ginseng is a traditional herbal medicine used for prevention and treatment of various diseases as a tonic. Recent scientific cohort studies on life prolongation with ginseng consumption support this record, as those who consumed ginseng for more than 5 years had reduced mortality and cognitive decline compared to those who did not. Clinical studies have also shown that acute or long-term intake of ginseng total extract improves acute working memory performance or cognitive function in healthy individuals and those with subjective memory impairment (SMI), mild cognitive impairment (MCI), or early Alzheimer’s disease (AD) dementia who are taking AD medication(s). Ginseng contains various components ranging from classical ginsenosides and polysaccharides to more recently described gintonin. However, it is unclear which ginseng component(s) might be the main candidate that contribute to memory or cognitive improvements or prevent cognitive decline in older individuals. This review describes recent clinical contributors to ginseng components in clinical tests and introduces emerging evidence that ginseng components could be novel candidates for cognitive improvement in older individuals, as ginseng components improve SMI cognition and exhibits add-on effects when co-administered with early AD dementia drugs. The mechanism behind the beneficial effects of ginseng components and how it improves cognition are presented. Additionally, this review shows how ginseng components can contribute to SMI, MCI, or early AD dementia when used as a supplementary food and/or medicine, and proposes a novel combination therapy of current AD medicines with ginseng component(s).

Effect of OPU Session Periods on the Efficiency of In Vitro Embryo Production in Elite Korean Native Cow

Choi, Byung-Hyun,Song, Seok-Hwan,Park, Bun-Young,Kong, Rami,Son, Mi-Ju,park, Chan-Sang,Shin, Nyeon-Hak,Cheon, Hye-Young,Lee, Sung-Hoon,Jin, Jong-In,Lee, Jung-Gyu,Kong, Il-Keun The Korean Society of Embryo Transfer 2018 한국동물생명공학회지 Vol.33 No.4

Up-to-date artificial insemination (AI) using frozen sperm consider as the most widely using technology for improvement of Korean Native Cow (Hanwoo) embryo production. However, it is time consuming, required at least 15~20 years to make more than 6 generations, and their offspring number is limited. To overcome such limitations, superovulation and in vitro fertilization have been developed. For superovulation, the number of produced embryos are not enough for commercialization and donor cows need rest period. This led to use of slaughterhouse ovary for in vitro fertilization, but it is impossible to repeat the collection from the same individual and it only can improve the genetic merits of offspring for one generation. Production of embryos using Ovum Pick-Up (OPU) technique, where oocytes can be repeatedly collected from living elite donor, might overcome these limitations. In this study, we investigated the possibility of using OPU technique from donors at different age and different session periods for mass-embryo-production. Oocytes were collected from 26 donor cows twice per week, 3 - 4 months per year, between 2013 and 2016. Results showed that, the average number of embryo produced in first year used donor was significantly higher than that in second year used donor ($3.89{\pm}2.85$ vs $3.29{\pm}2.70$), however, there was no significant difference between third year used donor ($3.51{\pm}3.32$) and other groups. Taken together, our data showed that repeated using of donor up to three years is possible for in vitro embryo mass-production. Moreover, OPU can be used as suitable embryo producing technique for livestock breed improvement.

A novel protocol for batch-separating gintonin-enriched, polysaccharide-enriched, and crude ginsenoside-containing fractions from Panax ginseng

Rami Lee,Han-Sung Cho,Ji-Hun Kim,Hee-Jung Cho,Sun-Hye Choi,Sung-Hee Hwang,Hyewon Rhim,Ik-Hyun Cho,Man-Hee Rhee,Do-Geun Kim,Hyoung-Chun Kim,Seung-Yeol Nah The Korean Society of Ginseng 2023 Journal of Ginseng Research Vol.47 No.3

Background: Ginseng contains three active components: ginsenosides, gintonin, and polysaccharides. After the separation of 1 of the 3 ingredient fractions, other fractions are usually discarded as waste. In this study, we developed a simple and effective method, called the ginpolin protocol, to separate gintonin-enriched fraction (GEF), ginseng polysaccharide fraction (GPF), and crude ginseng saponin fraction (cGSF). Methods: Dried ginseng (1 kg) was extracted using 70% ethanol (EtOH). The extract was water fractionated to obtain a water-insoluble precipitate (GEF). The upper layer after GEF separation was precipitated with 80% EtOH for GPF preparation, and the remaining upper layer was vacuum dried to obtain cGSF. Results: The yields of GEF, GPF, and cGSF were 14.8, 54.2, and 185.3 g, respectively, from 333 g EtOH extract. We quantified the active ingredients of 3 fractions: L-arginine, galacturonic acid, ginsenosides, glucuronic acid, lysophosphatidic acid (LPA), phosphatidic acid (PA), and polyphenols. The order of the LPA, PA, and polyphenol content was GEF > cGSF > GPF. The order of L-arginine and galacturonic acid was GPF >> GEF = cGSF. Interestingly, GEF contained a high amount of ginsenoside Rb1, whereas cGSF contained more ginsenoside Rg1. GEF and cGSF, but not GPF, induced intracellular [Ca²⁺]_i transient with antiplatelet activity. The order of antioxidant activity was GPF > GEF = cGSF. Immunological activities (related to nitric oxide production, phagocytosis, and IL-6 and TNF-α release) were, in order, GPF > GEF = cGSF. The neuroprotective ability (against reactive oxygen species) order was GEF > cGSP > GPF. Conclusion: We developed a novel ginpolin protocol to isolate 3 fractions in batches and determined that each fraction has distinct biological effects.

Integrated fire dynamic and thermomechanical modeling of a bridge under fire

Choi, Joonho,Haj-Ali, Rami,Kim, Hee Sun Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.6

This paper proposes a nonlinear computational modeling approach for the behaviors of structural systems subjected to fire. The proposed modeling approach consists of fire dynamics analysis, nonlinear transient-heat transfer analysis for predicting thermal distributions, and thermomechanical analysis for structural behaviors. For concretes, transient heat formulations are written considering temperature dependent heat conduction and specific heat capacity and included within the thermomechanical analyses. Also, temperature dependent stress-strain behaviors including compression hardening and tension softening effects are implemented within the analyses. The proposed modeling technique for transient heat and thermomechanical analyses is first validated with experimental data of reinforced concrete (RC) beams subjected to high temperatures, and then applied to a bridge model. The bridge model is generated to simulate the fire incident occurred by a gas truck on April 29, 2007 in Oakland California, USA. From the simulation, not only temperature distributions and deformations of the bridge can be found, but critical locations and time frame where collapse occurs can be predicted. The analytical results from the simulation are qualitatively compared with the real incident and show good agreements.

개인특성, 프로그램 참여특성, 돌봄부담이 자활효과에 미치는 영향

유라미, 최은영 충북대학교 생활과학연구소 2011 생활과학연구논총 Vol.15 No.2

-본문참고-

Effects of Gintonin-enriched fraction on the gene expression of six lysophosphatidic receptor subtypes

Rami Lee,Byung-Hwan Lee,Sun-Hye Choi,Yeon-Jin Cho,Han-Sung Cho,Hyoung-Chun Kim,Hyewhon Rhim,Ik-Hyun Cho,Man Hee Rhee,Seung-Yeol Nah 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.5

Background: Gintonin, isolated from ginseng, acts as a ginseng-derived lysophosphatidic acid (LPA) receptor ligand and elicits the [Ca<SUP>2+</SUP>]i transient through six LPA receptor subtypes (LPARSs). However, the long-term effects of gintonin-enriched fraction (GEF) on the gene expression of six LPARSs remain unknown. We examined changes in the gene expression of six LPA receptors in the mouse whole brain, heart, lungs, liver, kidneys, spleen, small intestine, colon, and testis after long-term oral GEF administration. Methods: C57BL/6 mice were divided into two groups: control vehicle and GEF (100 mg/kg, p.o.). After 21-day saline or GEF treatment, total RNA was extracted from nine mouse organs. Quantitative-real-time PCR (qRT-PCR) and western blot were performed to quantify changes in the gene and protein expression of the six LPARSs, respectively. Results: qRT-PCR analysis before GEF treatment revealed that the LPA6 RS was predominant in all organs except the small intestine. The LPA2 RS was most abundant in the small intestine. Long-term GEF administration differentially regulated the six LPARSs. Upon GEF treatment, the LPA6 RS significantly increased in the liver, small intestine, colon, and testis but decreased in the whole brain, heart, lungs, and kidneys. Western blot analysis of the LPA6 RS confirmed the differential effects of GEF on LPA6 receptor protein levels in the whole brain, liver, small intestine, and testis. Conclusion: The LPA6 receptor was predominantly expressed in all nine organs examined; long-term oral GEF administration differentially regulated LPA3, LPA4, and LPA6 receptors in the whole brain, heart, lungs, liver, kidneys, small intestine, and testis.

Brain correlates to facial motor imagery and its somatotopy in the primary motor cortex

Soliman, Ramy S.,Lee, Sanghoon,Eun, Seulgi,Mohamed, Abdalla Z.,Lee, Jeungchan,Lee, Eunyoung,Makary, Meena M.,Kathy Lee, Seung Min,Lee, Hwa-Jin,Choi, Woo Suk,Park, Kyungmo Wolters Kluwer Health | Lippincott Williams Wilkin 2017 NEUROREPORT - Vol.28 No.5

<P>Motor imagery (MI) has attracted increased interest for motor rehabilitation as many studies have shown that MI shares the same neural networks as motor execution (ME). Nevertheless, MI in terms of facial movement has not been studied extensively; thus, in the present study, we investigated shared neural networks between facial motor imagery (FMI) and facial motor execution (FME). In addition, FMI somatotopy within-face was investigated between the forehead and the mouth. Functional MRI was used to examine 34 healthy individuals with ME and MI paradigms for the forehead and the mouth. The general linear model and a paired t-test were performed to define the facial area in the primary motor cortex (M1) and this area has been used to investigate somatotopy between the forehead and mouth FMI. FMI recruited similar brain motor areas as FME, but showed less neural activity in all activated regions. The facial areas in M1 were distinguishable from other body movements such as finger movement. Further investigation of this area showed that forehead and mouth imagery tended to lack a somatotopic representation for position on M1, and yet had distinct characteristics in terms of neural activity level. FMI showed different characteristics from general MI as the former exclusively activated facial processing areas. In addition, FME and FMI showed different characteristics in terms of BOLD signal level, while sharing the same neural areas. The results imply a potential usefulness of MI training for rehabilitation of facial motor disease considering that forehead and mouth somatotopy showed no clear position difference, and yet showed a significant BOLD signal intensity variation. NeuroReport 28: 285-291 Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.</P>

Integrated fire dynamic and thermomechanical modeling of a bridge under fire

Joonho Choi,Rami Haj-Ali,김희선 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.6

This paper proposes a nonlinear computational modeling approach for the behaviors of structural systems subjected to fire. The proposed modeling approach consists of fire dynamics analysis, nonlinear transient-heat transfer analysis for predicting thermal distributions, and thermomechanical analysis for structural behaviors. For concretes, transient heat formulations are written considering temperature dependent heat conduction and specific heat capacity and included within the thermomechanical analyses. Also, temperature dependent stress-strain behaviors including compression hardening and tension softening effects are implemented within the analyses. The proposed modeling technique for transient heat and thermomechanical analyses is first validated with experimental data of reinforced concrete (RC) beams subjected to high temperatures, and then applied to a bridge model. The bridge model is generated to simulate the fire incident occurred by a gas truck on April 29, 2007 in Oakland California, USA. From the simulation, not only temperature distributions and deformations of the bridge can be found, but critical locations and time frame where collapse occurs can be predicted. The analytical results from the simulation are qualitatively compared with the real incident and show good agreements.

개인특성, 프로그램 참여특성, 돌봄부담이 자활효과에 미치는 영향

유라미(Rami Yoo),최은영(Eun Young Choi) 충북대학교 생활과학연구소 2011 생활과학연구논총 Vol.15 No.2

The purpose of this study is to examine the effects of individual characteristics, program participation, and care burden on self-sufficiency program participants' economic and emotional self-sufficiency. Subjects of this study consists of 331 self-sufficiency program participants in Chungnam province. For the economic self-sufficiency, voluntary participation in self-sufficiency program, occupational training provided by self-sufficiency promotion center, satisfaction level with staff at center, and child care burden turned out to be statistically significant variables. And child care burden is found out the most significant variable among these four variables. Statistically significant variables which is influencing attitude toward working as an emotional self-sufficiency are satisfaction level with staff at center, having child or not, and child care burden. And for the attitude toward living as an emotional self-sufficiency, participants' physical health, occupational training at center, having child or not, and child care burden were significant. Lastly, variables influencing attitude toward family relationship as an emotional self-sufficiency are participants' physical health, having child or not, and child care burden. Thus it is clear that child care burden is the most significant variable which affects both economic and emotional self-sufficiency. In conclusion, this study confirms that systematic health promotion services and active supports such as case management, counselling program for self-sufficiency program participants are much needed. Above all, it is pivotal to provide integrated supports for child care for better self-sufficiency performance.