3-분할 문제의 상자 채우기-교환 알고리즘

이상운 한국인터넷방송통신학회 2022 한국인터넷방송통신학회 논문지 Vol.22 No.4

This paper proposed a linear time algorithm for a three-partition problem(TPP) in which a polynomial time algorithm is not known as NP-complete. This paper proposes a backtracking method that improves the problems of not being able to obtain a solution of the MM method using the sum of max-min values and third numbers, which are known polynomial algorithms in the past. In addition, the problem of MM applying the backtracking method was improved. The proposed algorithm partition the descending ordered set  into three and assigned to the forward, backward, and best-fit allocation method with maximum margin, and found an optimal solution for 50.00%, which is 5 out of 10 data in initial allocation phase. The remaining five data also showed performance to find the optimal solution by exchanging numbers between surplus boxes and shortage boxes at least once and up to seven times. The proposed algorithm that performs simple allocation and exchange optimization with less   linear time performance complexity than the three-partition    of  data, and it was shown that there could be a polynomial time algorithm in which TPP is a P-problem, not NP-complete. 본 논문은 NP-완전으로 다항시간 알고리즘이 알려져 있지 않은 3-분할 문제(TPP)에 대한 선형시간 알고리즘을제안하였다. 본 논문은 기존에 알려진 다항시간 알고리즘인 최대-최소치와 제3의 숫자 합을 이용하는 MM법이 갖고있는 해를 구하지 못하는 문제점을 개선한 역추적 법을 제안하였으며, 또한 역추적 법을 적용한 MM의 문제점도 개선하였다. 제안된 알고리즘은 내림차순 정렬된  집합을 3-분할하여 순방향, 역방향과 최대 여유량 순서인 최적합 배정 법으로 배정한 결과 10개 데이터 중 5개 데이터인 50.00%에 대해서는 최적 해를 찾을 수 있었다. 나머지 5개 데이터에대해서도 최소 1회, 최대 7회의 잉여 상자와 부족 상자 간 숫자 교환으로 최적 해를 찾을 수 있는 성능을 보였다. 제안된알고리즘은 개 데이터를 3-분할한   보다도 적은  의 선형시간 수행 복잡도로 단순 배정과 교환 최적화를수행하는 알고리즘으로 TPP가 NP-완전이 아닌 P-문제인 다항시간 알고리즘이 존재할 수 있음을 보였다.

부패상품 임시물류센터에 대한 위치 문제 개선

이상운,Lee, Sang-Un 한국인터넷방송통신학회 2018 한국인터넷방송통신학회 논문지 Vol.18 No.3

This paper suggests simple algorithm of facility location problem in perishable commodities that satisfy with minimum total transportation cost and within the transportation time constraint $L^*$. For this problem, Lee[4] suggests very complex algorithm that decides candidate facility locations, computes total transportation cost for each candidate facility location, then moving the location to optimal location for top two facilities. On the other hand, this paper simply determines the candidate facility locations within $L^*$ using subtree concept, and decides optimal minimal total transportation cost for top two locations in centralized area of required quantity using neighborhood concept.

아세안 대상 ITS 표준화 협력 서비스분야 연구

이상운,Lee, SangWoon 한국ITS학회 2020 한국ITS학회논문지 Vol.19 No.5

In this paper, Korea's standardization capacity in the ITS field was examined, and the status of participation in ITS standardization and services of ASEAN countries, and the degree of hope for cooperation with Korea was investigated and analyzed. Korea is recognized for its international competency in the field of ITS standardization, and most ASEAN countries, excluding Singapore, are found to have insufficient participation in ITS standardization and service introduction. In addition, most ASEAN countries are strongly hoping for ITS standardization cooperation with Korea, and the preliminary establishment of the ITS system architecture as the basis for ITS standardization was derived as a project of hope for cooperation. In addition, as a service field for introducing standardization, Freight transport was suggested as a priority application service field in order to improve the efficiency of logistics transportation between ASEAN countries.

Ozone Assisted-MOCVD로 제작된 산화주석막의 전기적 광학적 특성

배정운(J. W. Bae),이상운(S. W. Lee),송국현(K. H. Song),박정일(J. I. Park),박광자(K. J. Park),염근영(G. Y. Yeom) 한국표면공학회 1998 한국표면공학회지 Vol.31 No.2

기생소자를 가지는 U-형태의 광대역 RFID 태그 안테나

이상운(Sangwoon Lee),조치현(Chihyun Cho),이기근(Keekeun Lee),추호성(Hosung Choo),박익모(Ikmo Park) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.1

본 논문에서는 UHF 대역에서 동작하는 기생소자를 가지는 U-형태의 광대역 RFID 태그 안테나를 제안하였다. 제안한 태그 안테나는 복사부에 해당하는 U-형태의 반파장 다이폴 안테나 상단 중앙에 역방향으로 U-형태의 기생소자를 삽입하였고, 본체 하단 중앙에 사각 형태의 급전 구조를 삽입하여 상용 태그 칩과 안테나의 공액정합을 용이하게 하였다. 제안된 태그 안테나는 VSWR<2를 기준으로 한 882~927 ㎒의 대역폭 안에서 3.16㏈ 이하의 이득편차 특성을 가졌고, VSWR<5.8을 기준으로 한 대역폭은 857~958.5 ㎒로 전 세계 UHF 대역폭을 모두 수용하였으며, 대역폭 내에서 5.07 ㏈ 이하의 이득편차 특성을 가졌다. 또한 최소 이득편차 특성이 대역폭 중심 주파수에 나오도록 하여 주파수에 따른 이득편차 특성 변화를 최소화하였다. In this paper, we proposed a U-shaped broadband RFID tag antenna with a parasitic element operating at UHF band. The proposed tag antenna consists of a U-shaped half wavelength dipole antenna and an inverse U-shaped parasitic element inside the U-shaped dipole antenna. In order to have good impedance matching, the commercial tag chip is attached to the lower center of the rectangular shaped feed. On the condition of VSWR<2, the tag antenna had the measured bandwidth of 4.96 % from 882 to 927 ㎒ and showed the gain deviation of less than 3.16 ㏈. On the condition of VSWR<5.8, the tag antenna satisfies the worldwide UHF RFID bandwidth and is showed the gain deviation of less than 5.07 ㏈. The minimum gain deviation characteristic appears near the center of bandwidth which minimizes variation of gain deviation characteristic with respect to the frequency.

다중 초기치 Pollards's Rho 소인수분해 알고리즘

이상운 한국인터넷방송통신학회 2017 한국인터넷방송통신학회 논문지 Vol.17 No.6

This paper deals with integer factorization of two prime p,q of SHA-256 secure hash value n for Bit coin mining. This paper proposes an algorithm that greatly reduces the execution time of Pollard's rho integer factorization algorithm. Rho(p) algorithm computes Xi=X²-1+1(modᥒ) and y²i-+1](modᥒ) for intial values (Xo,Yo)=(2,2) to find the factor 1<gcd(|Xi-Yi|,n)<n. It however fails to factorize some particular composite numbers. The algorithm proposed in this paper applies multiple initial values (Xo,Yo)=(2k,2k) and (2k,2),2≤k≤10 to the existing Pollard's Rho algorithm. As a results, the proposed algorithm achieves both the factorization of all the composite numbers and the reduction of the execution time of Pollard's Rho by . 본 논문은 비트코인 채굴에 필요한 SHA-256 암호 해시 값(n)을 구성하는 2개의 소수(p,q)를 빠르게 해독하는 소인수분해법을 다룬다. 본 논문에서는 Pollard's Rho 소인수분해 알고리즘의 수행횟수를 월등히 감소시킨 알고리즘을 제안하였다. Rho(p) 알고리즘은 (Xo,Yo)=(2,2) 초기치에 대해 Xi=X²-1+1(modᥒ)과 y²i-+1](modᥒ)을 계산하여 1<gcd(|Xi-Yi|,n)<n으로 소인수를 구한다. 이 알고리즘은 특정 합성수에 대해서는 소인수 분해에 실패할 수 있다. 제안된 알고리즘은 Pollard Rho 알고리즘에 (Xo,Yo)=(2k,2k)와 (2k,2),2≤k≤10을 적용하였다. 그 결과 모든 합성수에 대해 소인수분해를 할 수 있었으며, Pollard Rho 알고리즘의 수행횟수를 감소시켰다.

Joint stability of internal conical connection abutments with or without hexagon indexes: an in vitro study

이상운,차민상,이지혜,조리라,박찬진 대한턱관절교합학회 2020 구강회복응용과학지 Vol.36 No.2

Purpose: The purpose of this study was to compare the axial displacement of the hexagonal and conical abutment in internal conical connection implant after screw tightening and cyclic loading. Materials and Methods: Internal conical connection implants were divided into two groups (n = 10): group HEX, hexagonal abutment; and group CON, conical 2-piece abutments. The axial displacement and removal torque values were measured after 30 Ncm torque tightening and 250N loading test of 100,000 cycles. The Student t test with 5% significance level was used to evaluate the data. Results: HEX group demonstrated significantly higher axial displacement values after 30 Ncm tightening in comparison to the CON group (P < 0.05). No significant difference was found in axial displacement after cyclic loading (P = 0.052). Removal torque loss before and after the cyclic loading both revealed no significant difference between groups (P = 0.057 and P = 0.138). Removal torque value decreased after cyclic loading in both groups (P < 0.05). Conclusion: Overall, both abutment with or without hexagon index presented similar biomechanical performance except HEX group demonstrated significantly more axial displacement after applying tightening torque. (J Dent Rehabil Appl Sci 2020;36(2):95-103)

블록 보간 탐색법

이상운,Lee, Sang-Un 한국인터넷방송통신학회 2017 한국인터넷방송통신학회 논문지 Vol.17 No.5

The binary and interpolation search algorithms are the most famous among search area algorithms, the former running in $O(log_2n)$ on average, and the latter in $O(log_2log_2n)$ on average and O(n) at worst. Also, the interpolation search use only the probability of key value location without priori information. This paper proposes another search algorithm, which I term a 'hybrid block and interpolation search'. This algorithm employs the block search, a method by which MSB index of a data is determined as a block, and the interpolation search to find the exact location of the key. The proposed algorithm reduces the search range with priori information and search the reduced range with uninformed situation. Experimental results show that the algorithm has a time complexity of $O(log_2log_2n_i)$, $n_i{\simeq}0.1n$ both on average and at worst through utilization of previously acquired information on the block search. The proposed algorithm has proved to be approximately 10 times faster than the interpolation search on average.

BiNbO<SUB>4</SUB>:RE<SUP>3+</SUP> (RE = Dy, Eu, Sm, Tb) 형광체의 광학 특성

이상운(Sangwoon Lee),조신호(Shinho Cho) 한국표면공학회 2017 한국표면공학회지 Vol.50 No.3

BiNbO4:RE<SUP>3+</SUP> (RE = Dy, Eu, Sm, Tb) phosphors were prepared by solid-state reaction at 1100℃ and their structural, photoluminescent, and morphological properties were investigated. XRD patterns exhibited that all the synthesized phosphors exhibited a triclinic system with a dominant (210) diffraction peak, irrespective of the type of activator ions. The surface morphologies of rare-earth-ion-doped BiNbO4 phosphors were found to depend strongly on the type of activator ions. The Eu<SUP>3+</SUP> and Dy<SUP>3+</SUP> doped BiNbO4 phosphors revealed a strong red (613 nm) emission resulting from the <SUP>5</SUP>D0→<SUP>7</SUP>F2 transition of Eu<SUP>3+</SUP> and a dominant yellow (575 nm) emission originating from the <SUP>4</SUP>F9/2→<SUP>6</SUP>H13/2 transition of Dy<SUP>3+</SUP>, respectively, which were the electric dipole transitions, indicating that the activator ions occupy sites of non-inversion symmetry in the BiNbO4 phosphor. The main reddish-orange emission spectra of Sm<SUP>3+</SUP>-doped BiNbO4 phosphors were due to the <SUP>4</SUP>G5/2→<SUP>6</SUP>H7/2 (607 nm) magnetic dipole transition, indicating that the Sm<SUP>3+</SUP> ions were located at inversion symmetry sites in the BiNbO4 host lattice. As for Tb<SUP>3+</SUP>-doped phosphors, green emission was obtained under excitation at 353 nm and its CIE chromaticity coordinates were (0.274, 0.376). These results suggest that multicolor emission can be achieved by changing the type of activator ions incorporated into the BiNbO4 host crystal.

지상파 DMB(Digital Multimedia Broadcasting)

이상운,최병호 한국ITS학회 2004 한국ITS학회 학회지 Vol.2 No.1