An Adaptive Hot-spot Operating Scheme in Vertically Overlaid OFDMA Wireless Systems

최혜선,정희정,김낙명,Choi Hye-Sun,Chung Hee-Jeong,Kim Nak-Myeong The Korean Institute of Communications and Informa 2005 韓國通信學會論文誌 Vol.30 No.7a

OFDMA 하향링크 시스템에서 단말의 불균등한 위치 분포와 다양한 QoS 요구사항의 변화에 따라 시스템에 끼치는 부정적인 영향을 줄이기 위한 적응적 hot-spot 운용 기법에 대해 제안하였다. 매크로셀의 기지국은 셀 내 피고셀의 운용을 조절하며, 예측된 user outage probability와 AHOS 이득 파라미터 값에 의해 피코셀을 켜고 끄게된다. 제안된 AHOS 기법은 다양한 시스템 환경에서 QoS outage probability를 유지하면서 시스템의 throughput을 최대화 시키는 이득을 보였다. We develop an adaptive hot-spot operating scheme(AHOS) to mitigate the negative effects from the nonuniform distribution of user location and the variation in the mixture of QoS requirements in OFDMA downlink systems. The base station in a macrocell can control the operation of picocells within the cell, and turns on or off according to the changes in the estimated user outage probability and the AHOS gain parameter. With the computer simulation, the AHOS has been proved to maximize the system throughput while maintaining the QoS outage probability very low under various system scenarios.

온열적 쾌적과 의복의 보온력

최혜선,Choi Hei-Sun 대한설비공학회 1987 설비저널 Vol.16 No.3

5 ' - Deoxy - 5 ' - Iodoinosine 존재하에 사람 적혈구에서의 5 - Iodoribose 1 - phosphate 대사

최혜선,요하나 스토클러 ( Hye Seon Choi,Johanna D . Stoeckler ) 생화학분자생물학회 1990 BMB Reports Vol.23 No.3

5`-deoxy-5`-iodoadenosine (5`-IAdo) and 5`-deoxy-5`-iodoinosine (5`-IIno) were highly cytotoxic to several cell lines in vitro. These studies indicated that the pentose 1-phosphate generated from the 5`-iodonucleosides is responsible for the cytotoxicity. The synthesized and purified 5-iodoribose 1-phosphate (5-IR-1-P) inhibited several enzymes which are related to purine, pyrimidine and sugar phosphate metabolism. Intracellular concentrations of 5-IR-1-P were measured in human erythrocytes through which are in transit to a target site. 560 uM of 5`-IIno generated 500 uM 5-IR-1-P in human erythrocytes. Intracellular concentrations of 5-IR-1-P reached plateau levels in less than 1 hr which remained unchanged for 4 hr. Following removal of extracellular 5`-IIno, the intracellular concentrations of 5-IR-1-P decreased from 500 uM to 300 uM. Intracellular concentration of 5-IR-1-P declined progressively during the subsequent incubation, indicatng that rapidly continuing degradation of 5-IR-1-P occurred in the absence of further synthesis of 5-IR-1-P from 5`-IIno.

논문편 : 시판 임산부용 거들의 착용감 및 착용효과에 관한 연구

최혜선,이경화 ( Hei Sun Choi,Kyong Hwa Yi ) 대한가정학회 1991 Family and Environment Research Vol.29 No.3

Kinetics of Intracellular Adenosine Deaminase to Substrate Analogs and Inhibitors in Aspergillus oryzae

최혜선,Choi, Hye-Seon The Microbiological Society of Korea 1994 미생물학회지 Vol.32 No.1

Adenosine deaminase (ADA)의 여러 기질과 억제물질의 반응 속도론적 상수가 Aspergillusoryzae의 세포내 효소인 ADA의 활성자리에 어떻게 부착하고 어떤 요인을 필요로 하는지를 알기위해 측적되어졌다. kcat/$K_m$값에 의하면 조사된 기질로 작용하는 화합물 중에 3'-deoxyadenosine이 가장 좋은 기질로 작용하는 것으로 밝혀졌다. 몇 개의 유사체가 억제물질로 조사되었는데 purine riboside가 $3.7{\times}10^{-5}$M의 값 $K_i$값을 가지고 가장 강한 억베물질로 나타났다. Adenine은 기질로도 억제물질로도 작용을 못하므로 adenine의 N-9 위치의 ribose가 효소에 부착하는데 중요하다는 것을 시사하고 있다. 또 ADA는 6-chloropurine riboside(6-CPR)의 dechlorination을 촉매화하여 inosine과 Cl이온을 생성한다. 6-CPR의 ADA에 대한 기질 특이성은 정상 기질인 adenine의 0.86%로 측정되었다. ADA의 경쟁적 억제물질인 purine riboside는 비슷한 $K_i$값을 가지고 dechlorination도 억제하므로 deamination과 dechlorination 반응은 효소의 부착자리를 공유하고 있다고 생각되어진다. SH기에 작용하는 화합물중 수은제인 p-chloromercuribenzoate(PCMB), mersalyl acid, $HgCl_2$는 효소의 deamination 반응을 억제했다. Mersalyl acid에 의해 활성이 억제된 ADA는 thiol reagent인 dithiothreitol이나 2-mercaptoethanol에 의해 활성이 회복되지만 PCMB에 의해 억제된 효소는 회복되지 않았다. 각 수은제들이 억제물질로 작용할 때 $K_i$값과 억제양상이 측정되었는데 모두 경쟁적 방해를 보였다. $K_i$값은 10mM 인산완충용액에서 측정한 것이 100 mM 인산완충용액에서 측정한 것보다 훨씬 낮아 인산기가 기질이 아니어도 효소의 부착에 큰 영향을 미치는 것을 보여주고 있다. Kinetic parameters of various substrates and inhibitors were measured to elucidate the binding requirements of the active site of intracellular adenosine deaminase (ADA) in Aspergillus oryzae. 3'-Deoxyadenosine was the best substrate according to the value of relative kcat/$K_m$. Purine riboside was found to be the strongest inhibitor with the $K_i$ value of $3.7{\times}10^{-5}$M. Adenine acted neither as a substrate nor as an inhibitor, suggesting the presence of ribose at N-9 of adenosine was crucial to binding. ADA also catalyzed the dechlorination of 6-chloropurine riboside, generating inosine and chloride ions. Substrate specificity of 6-chloropurine riboside was 0.86% of adenosine. Purine riboside, a competitive inhibitor of ADA, inhibit the dechlorination with similar $K_i$ value, suggesting that the same binding site was involved in deamination and dechlorination. Among the sulfhydryl group reagents, mercurials, pchloromercuribenzoate (PCMB), mersalyl acid and $HgCl_2$ inactivated the enzyme. Mersalyl acid-inactivated ADA was reactivated by thiol reagents, but PCMB-inactivated enzyme was not. When ADA was treated with the mercurial reagents, the inhibition constants and inhibition patterns were determined. Each inhibition was competitive with substrate. The $K_i$ values of these mercurial reagents were lower in 10 mM phosphate buffer than in 100 mM phosphate buffer, showing phosphate dependency.

보문 : 의복설계를 위한 비만 여성 체형의 연령층별 특징

최혜선,이진희 ( Hei Sun Choi,Jin Hee Lee ) 한국의류학회 1995 한국의류학회지 Vol.19 No.5

중년여성 기성복의 치수체계에 관한 연구

최혜선,이경미 ( Hei Sun Choi,Kyung Mi Lee ) 대한가정학회 1995 Family and Environment Research Vol.33 No.1

Saccharomyces cerevisiae에서 얻은 Purine Nucleoside Phosphorylase의 반응기작과 효소에 대한 Sulfhydryl Reagent의 영향

최혜선,Choi, Hye-Seon 한국미생물학회 1994 미생물학회지 Vol.32 No.3

Saccharomyces cerevisiae에서 얻은 purine nucleoside phosphorylase (PNP)의 반응 기작을 밝히기 위해 반응속도론적 분석이 수행되어졌다. 반응기작에 PNP${\cdot}$phosphate와 PNP${\cdot}$ribose 1-phosphate의 binary complex가 형성되는 것으로 추정되어진다. Initial velocity와 product inhibition study의 결과는 반응이 ordered bi, bi reaction으로 일어난다는 것과 일치하고 있다. 두 개의 기질중 무기인산이 효소에 먼저 붙고, 그 다음에 nucleoside, 그리고 base가 효소를 떠나는 첫 번째 생성물이고 마지막으로 ribose 1-phosphate가 생성되고 효소는 원래의 상태로 돌아간다. 반응속도론적 분석에 이해 제안된 작용기작은 sulfhydryl reagents인 p-chloromercuribenzoate(PCMB) and 5,5'-dithiobisnitrobenzoate (DTNB)에 의한 효소의 불활성화에 대한 기질으 보호작용의 결과와 일치하고 있다. PNP는 ribose 1-phosphate와 phosphate에 의해 보호되지만 nucleoside나 base에 의해서는 아무런 효과과 없다는 사실은 반응 순서가 효소에 무기인산이 먼저 붙는 ordered bi, bi 기작이라는 것을 지지하고 있다. PCMB 나 DTNB에 의해 불활성화된 PNP는 dithiothreitol(DTT)에 의해서는 활성이 완전히 회복되고 2-mercaptoethanol에 의해서는 77%의 활성이 회복된다는 사실은 효소의 불활성화가 가역적이라는 것을 시사하고 있다. PCMB에 의해 불활성화된 효소는 inosine이 변화하는 기질일때 정상효소보다 높은 $K_m$과 낮은 $V_m$ 값을 보여주고 이런 현상은 DTT 처리시 원래의 상태로 돌아온다. DTNB에 의해 불활성화된 효소는 PCMB 처리시와 비슷하게 정상효소보다 높은 $V_m$ 값을 보이지만 $V_m$ 값은 큰 변화가 없다. S. cerevisiae PNP에서 발견되는 높은 무기인산의 농도에서의 하위단위체간의 음성적 협동성이 PCMB나 DTNB를 처리한 PNP에서는 보이지 않았다. Kinetic analysis was done to elucidate the reaction mechanism of purine nucleoside phosphorylase (PNP) in Saccharomyces cerevisiae. The binary complexes of PNP${\cdot}$phosphate and PNP${\cdot}$ribose 1-phosphate were involved in the reaction mechanism. The initial velocity and product inhibition studies demonstrated were consistent with the predominant mechanism of the reaction being an ordered bi, bi reaction. The phosphate bound to the enzyme first, followed by nucleoside and base were the first product to leave, followed by ribose 1-phosphate. The kinetically suggested mechanism of PNP in S. cerevisiae was in agreement with the results of protection studies against the inactivation of the enzyme by sulfhydryl reagents, p-chloromercuribenzoate (PCMB) and 5,5'-dithiobisnitrobenzoate (DTNB). PNP was protected by ribose 1-phosphate and phosphate, but not by nucleoside or base, supporting the reaction order of ordered bi, bi mechanism. PCMB or DTNB-inactivated PNP was totally reactivated by dithiothreitol (DTT) and the activity was returned to the level of 77% by 2-mercaptoethanol, indicating that inactivation was reversible. The kinetic behavior of the PCMB-inactivated enzyme had been changed with higher $K_m$ value of inosine and lower $V_m$, and was restored by DTT. Inactivation of enzyme by DTNB showed similar pattern of K sub(m) value with that by PCMB, but had not changed the $V_m$ value, significantly. Negative cooperativity was not found with PCMB or DTNB treated PNP at high concentration of phosphate.

표준실내기후 설정에 관한 기초조사연구 -열환경요소와 착의량이 온냉감반응에 미치는 영향-

최혜선,Choi Hei Sun 대한설비공학회 1987 설비저널 Vol.16 No.6

The purpose of this study was to investigate thermal environmental factors, thermal clothing properties, and thermal sensation of the office workers in four selected office buildings in Seoul, and to determine the effect of thermal environmental factors and clothing insulation to the thermal sensation of the subjects. The subjects selected from each office were 5 males and 5 females at a time. Thermal environmental factors(DBT, GT, RH, MRT, $ET^{\ast}$) and clothing variables such as clothing weight per body surface $area(g/m^2)$ and estimated clothing insulation values(clo) were significantly different among each seasons(p<0,001). Means of $ET^{\ast}$ and estimated clothing insulation values of each season were as follows; Winter; $20.84^{\circ}C$ $ET^{\ast}$ with 0.72 clo for male and 0.79 clo for female Spring and fall; $23.65^{\circ}C$ $ET^{\ast}$ with 0.59 clo for male and 0.68 clo for female Summer; $26.00^{\circ}C$ $ET^{\ast}$ with 0.47 clo for male and 0.53 clo for female. In comparison these data with ASHRAE Standard, the subjects were predicted to feel comfort-able in spring and fall, and slightly hot in summer and slightly cold in winter because of high and low clo respectively. But the result of this survey showed more than $80\%$ of the occupants were thermally comfortable at a given environmental temperature and clo.

MTA 유사체의 Purine Metabolism 에의 영향

최혜선,J . D . Stoecker ( Hye Seon Choi,J . D . Stoeckler ) 생화학분자생물학회 1992 BMB Reports Vol.25 No.1

5`-Deoxy-5`-methylthioadenosine (MTA) which is related to polyamine synthesis, is rapidly converted to 5-methylthioribose 1-phosphate (MTR-1-P) and adenine by the reaction of MTA phosphorylase (MTAPase) (Savarese et al., 1981). MTA analogs in which the ribose moiety was replaced have demonstrated to be cytotoxic (Savarese et al., 1984; Ferro et al., 1982). These results indicated that the common product, 5-modified sugar phosphate, exerted cytotoxic effect against several tumor cells. L5178Y mouse lymphoblastic leukemia cells were treated with 5`-modified adenosines, MTA, 5`-deoxy-5`-isobutylthioadenosine (SIBA), 5`-deoxy-5`-iodoadenosine (5`-IAdo) and 5`-deoxyadenosine (5`-dAdo). The phosphorolysis of 100 μM of 5`-modified nucleosides measured in intact L5178Y cells agreed well with the relative V_m of MTAPase from Sarcoma 180 cells determined by Savarese et al. (1983). 5`-IAdo showed extra inhibition of 5-phosphoribosyl 1-pyrophosphate (PRPP) synthesis at high concentration, but the inhibition by 5`-dAdo, MTA and SIBA could be due to adenine released from 5`-substituted adenosines. 5`-Modified adenosines caused greater inhibition of purine synthesis de novo than the same concentration of adenine as were generated from the 5`-substituted adenosines. No inhibition of purine salvage pathway was observed. 5`-IAdo was most cytotoxic and inhibited purine metabolism to the greatest extent in L5178Y cells. In the HL-60 human promyelocytic leukemia cells and HL-60, APRT-deficient mutant cells, the effects of 5`-IAdo on purine and pyrimidine metabolism were measured. 5`-IAdo had no significant effects on PRPP accumulation, purine synthesis de novo and purine salvage pathway.