• Journal of information and communication convergence engineering
• /
• 제9권2호
• /
• pp.172-176
• /
• 2011

In the Gen-2 Q-algorithm, the values of weight C, which is the parameter for incrementing or decrementing the slot-count size, are not optimized in the standard. However, the standard suggests that the reader uses small values of C when the slot-count is large and larger values of C when the slot-count is small. In this case, if the reader selects an inappropriate weight, there are a lot of empty or collided slots. As a result, the performance will be declined because the frame size does not converge to the optimal point quickly during the query round. In this paper, we propose a scheme to select the weight based on the slot-count size of current query round. Through various computer simulations, it is demonstrated that the proposed scheme achieves more stable performances than Gen-2 Q-algorithm.

• 대한수학회보
• /
• 제38권2호
• /
• pp.347-355
• /
• 2001

Let ($X, \omega$) be a closed symplectic 4-manifold. Let a finite cyclic group G act semifreely, holomorphically on X as isometries with fixed point set $\Sigma$(may be empty) which is a 2-dimension submanifold. Then there is a smooth structure on the quotient X'=X/G such that the projection $\pi$:X$\rightarrow$X' is a Lipschitz map. Let L$\rightarrow$X be the Spin$^c$ -structure on X pulled back from a Spin$^c$-structure L'$\rightarrow$X' and b_2^$+(X')>1. If the Seiberg-Witten invariant SW(L')$\neq$0 of L' is non-zero and $L=E\bigotimesK^-1\bigotimesE$ then there is a G-invariant pseudo-holomorphic curve u:$C\rightarrowX$,/TEX> such that the image u(C) represents the fundamental class of the Poincare dual $c_1$(E). This is an equivariant version of the Taubes' Theorem.

• 대한수학회지
• /
• 제41권3호
• /
• pp.479-487
• /
• 2004

Let G be a finite group and N be a normal subgroup of G. We denote by ncc(N) the number of conjugacy classes of N in G and N is called n-decomposable, if ncc(N) = n. Set $K_{G}\;=\;\{ncc(N)$\mid$N{\lhd}G\}$. Let X be a non-empty subset of positive integers. A group G is called X-decomposable, if KG = X. In this paper we characterise the {1, 3, 4}-decomposable finite non-perfect groups. We prove that such a group is isomorphic to Small Group (36, 9), the $9^{th}$ group of order 36 in the small group library of GAP, a metabelian group of order $2^n{2{\frac{n-1}{2}}\;-\;1)$, in which n is odd positive integer and $2{\frac{n-1}{2}}\;-\;1$ is a Mersenne prime or a metabelian group of order $2^n(2{\frac{n}{3}}\;-\;1)$, where 3$\mid$n and $2\frac{n}{3}\;-\;1$ is a Mersenne prime. Moreover, we calculate the set $K_{G}$, for some finite group G.

• Journal of information and communication convergence engineering
• /
• 제7권4호
• /
• pp.469-474
• /
• 2009

Q-algorithm is proposed at EPC global Class-1 Generation-2 RFID systems to determine the frame size of next query round. In Q-algorithm, the reader calculates the frame size without estimating the number of tags. But, it uses only the slot conditions: empty, success, or collision. Therefore, it wastes less computational cost and is simpler than other algorithms. However, the constant parameter C value, which is used for calculating the next frame size, is not optimized. In this paper, we propose the optimized C values of Q-algorithm according to the number of tags within the identification range of reader through a lot of computer simulations.

• Journal of information and communication convergence engineering
• /
• 제8권5호
• /
• pp.519-523
• /
• 2010

In Gen-2 RFID system, the initial value of $Q_{fp}$, which is the slot-count parameter of Q-algorithm, is not defined in the standard. In this case, if the number of tags within the reader's identification range is small and we let the initial $Q_{fp}$ be large, the number of empty slot will be large. On the other hand, if we let the initial $Q_{fp}$ be small in spite of many tags, almost all the slots will be collided. As a result, the performance will be declined because the frame size does not converge to the optimal point quickly during the query round. In this paper, we propose a scheme to allocate the optimal initial $Q_{fp}$ through the tag number estimation before the query round begins. Through computer simulations, it is demonstrated that the proposed scheme achieves more stable performance than Gen-2 Q-algorithm.

• Journal of the Korean Statistical Society
• /
• 제30권4호
• /
• pp.661-666
• /
• 2001

In this paper we consider an M/G/1 queue where the server of the system has a vacation time and the service policy is limited-1. In this system, upon termination of a vacation the server returns to the queue and serves at most one message in the queue before taking another vacation. We consider two models. In the first, if the sever finds the queue empty at the end of a cacation, then the sever immediately takes another vacation. In the second model, if no message have arrived during a vacation, the sever waits for the first arrival to serve. The analysis of this system is particularly useful for a priority class polling system. We derive Laplace-Stieltjes transforms of the waiting time for both models, and compare their mean waiting times.

• Journal of Chest Surgery
• /
• 제34권11호
• /
• pp.875-878
• /
• 2001

배경: 비록 경화요법이 정맥류를 치료하는데 확립된 방법일지라도 그 성공률에는 차이가 있다. 따라서 이 연구의 목적은 압박경화요법의 치료효과와 합병증을 평가하는데 있다. 대상 및 방법: 2000년 12월부터 2001년 9월까지 일차성 하지 정맥류 환자중 압박경화요법을 시행 받은 39명(50예의 하지)을 대상으로 하였다. 주사한 직후 정맥류의 경로를 따라서 탈지면롤을 댄 후, 다시 class II 압박스타킹을 신겼다. 환자는 치료효과와 합병증의 정도를 보기 위해서 시술후 5일, 1주, 2주, 6주에 평가되었다. 결과: 환자의 연령은 26세에서 66세까지로 평균 45.3세이었으며 여자 36명, 남자 3명이었다. 모든 환자에서 경화요법의 결과는 우수하였다. 50례의 하지 중 5례에서만 작은 합병증이 있었는데 2례의 혈관내 작은 응혈, 2례의 색소침착, 1례의 압박으로 인한 수포가 있었다. 이는 특별한 치료 없이 모두 회복되었다. 결론: 국소 압박도구로써 탈지면롤은 매우 손쉽고 효과적이며, 압박경화용법은 경제적 부담이 적고 안전하고 효과적인 치료법이다.

• 한국식품조리과학회지
• /
• 제23권3호통권99호
• /
• pp.321-326
• /
• 2007

The microbial contamination levels of school classrooms were assessed as foodservice environments for elementary students. Two elementary schools located in Kyunggi-do were selected, and the total plate counts (TPC) and coliforms were measured from the classroom facilities, including the tables, chairs, floors, shelves, doors, as well as the hands of students, and the air of classrooms. The TPC of the classroom facilities were relatively low ranging from 2.30 to 3.79 log CFU/100 cm$^2$. The TPC counts from the hands of serving students and served students, were 6.39 and 5.33 log CFU, respectively, and the TPC counts of the foodservice utensils were <3.00 log CFU/ea before use and 4.77 CFU/ea after use. The air samples of 'empty classrooms during physical education', 'after physical education class', and 'during lunch' showed the contamination levels of 26 CFU/m$^3$,392 CFU/m$^3$, 364 CFU/m$^3$, respectively, suggesting that the microbial levels in the air varies greatly depending on the class activity before foodservice. When the TPCs of the air during lunch were measured from 18 classrooms, the levels ranged from 76 to >2228 CFU/m$^3$. Coliforms were not detected in the classroom facilities; however, air samples of the classrooms showed 1${\sim}$2 CFU/m$^3$. The above results show that classroom air and the hands of students, can have high levels of microbial contamination, which must to be controlled for safer school foodservice.

• 한국실내디자인학회논문집
• /
• 제13권5호
• /
• pp.125-132
• /
• 2004

The purpose of this study is focused on defining the types of spatial configuration of internal functions in city hotels by researching and analyzing city hotels in Korea and Japan. The scope of this study is limited to the period of early 1980's to the end of 1990's and 18 city hotels in Korea and Japan are selected as subject. Researching existing records and analyzing plans, surveys are used as the method of the study. The result of this study is as follow. First, block composition of floor plans that is used for hotel construction could be divided into three types (immanent type-6hotels, combined type-7hotels, adjacent type-4hotels). Second, the result of analysis about the internal functions and structural types of public area in city hotels is as follow. More Korean city hotels are taking concourse type (Korea 77.8%, Japan 55.6%) and hall type (Korea 22.2%, Japan 11.1%) than Japanese city hotels. However, the mixed type (concourse type +hall type) is only used in Japan (Korea 0%, Japan 33.3%). Third, as the result of the comparison of the size of public area between Korea and Japan, Korean hotels (36.70%) have larger space than Japanese hotels only in the service area. public (Korea 33.98% < Japan 34.71%), business (Korea 27.68% Japan 31.41%)and empty (Korea 1.64% < Japan 6.13%) area is taking larger space in Japanese city hotels than Korean.

• 복식
• /
• 제57권6호
• /
• pp.135-144
• /
• 2007

This study is about the three pieces of jackets with a symmetric collar that was used to fill in the empty spaces in coffin excavated in 2004, from Seok-nam-dong, Nam-gu, Incheon. The similarities of these three jackets are that the collars are symmetric, there are seops(the outer bodies to overlap the front sides of a jacket) with pleats, and openings on the side seam. The No.2, and No.6 seem to be jegori to wear over others, and the fabrics used for No.2 is damask with cloud pattern, and damask with lotus flower pattern. For the No.4, satin was used and there is peacock pattern weaved on satin using golden thread. No.41 is unlined clothes made with Suk-cho, and the distinctive feature about this clothes is that the collar, and the neckline are very narrow. The three jackets are similar with the recently reported clothes of Kim clan of Gang-leung (deducted to be buried in 1520), the collection of Seok Joo-sun Memorial Museum. Through this report, it provides information about some aspects of upper class women's clothes.