• 호남수학학술지
• /
• 제30권4호
• /
• pp.603-616
• /
• 2008

A generalized n-dimensional Riemannian manifold $X_n$ on which the differential geometric structure is imposed by the unified field tensor $^*g^{{\lambda}{\nu}}$, satisfying certain conditions, through the $^*g$-ME-connection which is both Einstein's equation and of the form(3.1) is called $^*g$-ME-manifold and we denote it by $^*g-MEX_n$. In this paper, we prove a necessary and sufficient condition for the existence of $^*g$-ME-connection and derive a surveyable tensorial representation of the $^*g$-ME-connection and the $^*g$-ME-vector in $^*g-MEX_n$.

• 충청수학회지
• /
• 제23권3호
• /
• pp.495-510
• /
• 2010

An Einstein's connection which takes the form (2.23) is called a $^*g$-ME-connection and the corresponding vector is called a $^*g$-ME-vector. The $^*g$-ME-manifold is a generalized n-dimensional Riemannian manifold $X_n$ on which the differential geometric structure is imposed by the unified field tensor $^*g^{{\lambda}{\nu}}$, satisfying certain conditions, through the $^*g$-ME-connection and we denote it by $^*g-MEX_n$. The purpose of this paper is to derive a general representation and a special representation of the $^*g$-ME-vector in $^*g-MEX_n$.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제2권2호
• /
• pp.63-81
• /
• 2008

WiMAX has been introduced as a competitive alternative for metropolitan broadband wireless access technologies. It is connection oriented and it can provide very high data rates, large service coverage, and flexible quality of services (QoS). Due to the large number of connections and flexible QoS supported by WiMAX, the uplink access in WiMAX networks is very challenging since the medium access control (MAC) protocol must efficiently manage the bandwidth and related channel allocations. In this paper, we propose and investigate a cost-effective WiMAX bandwidth management scheme, named the WiMAX partial sharing scheme (WPSS), in order to provide good QoS while achieving better bandwidth utilization and network throughput. The proposed bandwidth management scheme is compared with a simple but inefficient scheme, named the WiMAX complete sharing scheme (WCPS). A maximum entropy (ME) based analytical model (MEAM) is proposed for the performance evaluation of the two bandwidth management schemes. The reason for using MEAM for the performance evaluation is that MEAM can efficiently model a large-scale system in which the number of stations or connections is generally very high, while the traditional simulation and analytical (e.g., Markov models) approaches cannot perform well due to the high computation complexity. We model the bandwidth management scheme as a queuing network model (QNM) that consists of interacting multiclass queues for different service classes. Closed form expressions for the state and blocking probability distributions are derived for those schemes. Simulation results verify the MEAM numerical results and show that WPSS can significantly improve the network’s performance compared to WCPS.

• 한국토양비료학회지
• /
• 제8권1호
• /
• pp.31-35
• /
• 1975

무기영양면(無機營養面)(여기에서는 수확시(收穫時)의 지엽중(止葉中)의 K, Ca, Mg)에서 다수확(多收穫)벼의 소질(素質)을 밝히고 동(同)벼를 만드다데 필요(必要)한 토양조건(土壤條件)을 살피고저 각(各) 3수준(水準)의 석회(石灰), 인산(燐酸), 가리(加里)를 조합(組合) 실시(實施)한 시험(試驗)에서 지엽(止葉)과 시험후(試驗後) 토양(土壤)을 채취분석(採取分析)하는 외(外)에 시험전(試驗前) 토양(土壤)을 가지고 실내시험(室內試驗)한 결과(結果)는 다음과 같다. 1. 일반(一般)으로 다수확(多收穫)벼일수록 지엽중(止葉中)에 K가 많고 Ca, Mg 가 적었다. 이 결과(結果)에 의(依)하여 보면 다수확(多收穫)벼는 생식생장기(生殖生長期)에가서 K를 많이, Ca와 Mg 을 적게 흡수(吸收)해야 하는것 같다. 2. 10a 당(當) 600kg 의 정조(正租) (본(本)시험(試驗)에서는 비교적(比敎的) 많은 함량(含量)임)를 생산하는 벼의 지엽(止葉)(무수물(無水物))중(中)에는 K함량(含量)이 $30{\sim}35m{\cdot}e/100g$, Ca 함량(含量)이 $25m{\cdot}e/100g$ 이하(以下), Mg 함량(含量)이 $10m{\cdot}e/100g$ 이하(以下)이었으며 $K/{\sqrt{Ca+Mg}}$ 비율(比率)은 5 또는 그 이상(以上)이었다. 3. 시험후(試驗後) 토양(土壤)의 치환성가량(置換性加量)(Ke) 또는 치환성(置換性)K와 ${\sqrt{Ca+Mg}}$ 비(比) 즉 $K/{\sqrt{Ca+Mg}}$와 정조수량간(正組收量間)에 높은 정상관(正相關) 관계(關係)가 있다. 4. 정상수량(正相收量)(Y)과 시험후(試驗後) 토양(土壤)의 치환성(置換性) 가리(加里)(Ke) 및 $K/{\sqrt{Ca+Mg}}$ 비(比)의 회귀관계(回歸關係)는 다음과 같다. Y=183.95+2135.86 Ke $$Y=352.45+3114.454\;K/{\sqrt{Ca+Mg}}$$ 5. 시험후(試驗後) 토양(土壤)의 치환성가리(置換性加里) (Ke) 와 석회(石灰)(L) 및 가리(加里)(P)의 시용량간(施用量間)의 회귀관계(回歸關係)는 하기식(下記式)과 같다. $$Ke=0.1246+0.00007037L+0.004444P+0.000004444L{\cdot}P$$.