• Title/Summary/Keyword: Development delay

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Development of Gateway Review System for Supporting Collaborative Decision-Making through Project Life Cycle (사업 단계별 의사결정 지원 게이트웨이 리뷰 체계 구축)

  • Shin, Seung-Woo;Yi, June-Seong;Lee, Jee-Hee;Park, Kyung-Rog;Lim, Ji-Youn
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.3
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    • pp.43-54
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    • 2010
  • As Urban Regeneration is being carried out, stakeholders are most likely to have disagreements on their interests. Besides, dispersion of numerous communication routes and obscure decision processes aggravate the situation. Eventually, fragmented decision-making processes and complex structure lead to inefficient outcome and delay of projects. This paper is a study on decision-making support not only helps the program manager have more efficient and optimum decision, but also provides alternatives for Urban Regeneration. This study is conducted as follows. Firstly, the project process and the decision-making structure among stakeholders in Urban Regeneration are analyzed, and then the current status of decision-making in Urban Regeneration project is classified. Secondly, with literature study on "Gateway Review", the decision-making gateway review process in Urban Regeneration is defined, and then the "Gateway Review Elements" are listed. Thirdly, to establish gateway review process, this paper presents a check points, namely gate which supports a program manager to monitor and to control the program management in Urban Regeneration. Each gate has several supporting tools such as diagram of critical decision points relation, scheme of stakeholder, checklist. Fourthly, the proposed concept is verified by experts who have been carefully selected to provide their respective reviews. Finally, decision-making support gateway review system is modified based on their critiques and suggestions.

Update Frequency Cache Consistency for Reducing Wait Time in Mobile Computing (이동 컴퓨팅 환경에서 대기 시간을 감소시키는 갱신 빈도 캐쉬 일관성 기법)

  • Lee, Chan-Seob;Kim, Dong-Hyuk;Baek, Joo-Hyun;Choi, Eui-In
    • The KIPS Transactions:PartD
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    • v.9D no.6
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    • pp.1017-1024
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    • 2002
  • According as mobile computing environment is generalized by development of wireless networking technology and communication device, mobile host uses local cache for extensibility and early response time. and reduction of limited bandwidth. This time, between mobile host and mobile support station cache need consistency interested person of done data accordingly much techniqueses propose. Existent consistency techniques because detection based techniqueses are used mainly and broadcast periodic invalid message considering frequent disconnection. However, these techniqueses increase abort step through increase or delay of transmission message number by accuracy examination of data. Therefore, because mobile host deletes cached data, and extensity are decreased. Techniques that is proposed in this paper did to perform refering update frequency about object that page request or when complete update operation happens to solve these problem. Therefore, have advantage that response is fast because could run write intention declaration or update by update frequency electively asynchronously when update operation consists and abort step decreases. Also, improved extensity running delete or propagation electively according to update frequency about periodic invalid message gone since disconnection.

Data Synchronization Among Mobile Servers in Wireless Communication (무선통신 환경에서 이동 서버간의 데이터 동기화 기법)

  • Kim, Eun-Hee;Choi, Byung-Kab;Lee, Eung-Jae;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.13D no.7 s.110
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    • pp.901-908
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    • 2006
  • With the development of wireless communication techniques and mobile environment we are able to transmit data between mobile systems without restriction of time and space. Recently, researches on the data communication between mobile systems have focused on a small amount of sending out or receiving data and data synchronization at a fixed server and mobile clients in mobile environment. However, two more servers should be able to move mutual independently, information is shared with other systems, and data is synchronized in the special environment like a battlefield situation. Therefore, we propose a data synchronization method between systems moving mutual independently in mobile environment. The proposed method is an optimization solution to data propagation path between servers that considers limited bandwidth and process of data for disconnection communication. In addition, we propose a data reduction method that considers importance and sharing of information in order to reduce data transmission between huge servers. We verified the accuracy of data after accomplishing our data synchronization method by applying it in the real world environment. Additionally, we showed that our method could accomplish data synchronization normally within an allowance tolerance when we considered data propagating delay time by server extension.

Centralized TDMA Slot Assignment Scheme Based on Traffic Direction for QoS Guarantee in Unmanned Robot Systems (무인로봇체계에서 QoS 보장을 위한 트래픽 방향 기반 중앙집중식 TDMA 슬롯 할당 기법)

  • Han, Jina;Kim, Dabin;Ko, Young-Bae;Kwon, DaeHoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.5
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    • pp.555-564
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    • 2016
  • This paper proposes a time slot allocation scheme for military patrol environments. This proposal comes from analysis of traffic properties in a military patrol environment. In the near future, robots are expected to explore enemy grounds and measure threat, taking the place of human patrol. In order to control such robots, control messages must be extremely accurate. One mistake from the control center could cause a tragedy. Thus, high reliability must be guaranteed. Another goal is to maintain a continual flow of multimedia data sent from patrol robots. That is, QoS (Quality of Service) must be guaranteed. In order to transmit data while fulfilling both attributes, the per-path based centralized TDMA slot allocation scheme is recommended. The control center allocates slots to robots allowing synchronization among robots. Slot allocation collisions can also be avoided. The proposed scheme was verified through the ns-3 simulator. The scheme showed a higher packet delivery ratio than the algorithm in comparison. It also performed with shorter delay time in the downlink traffic transmission scenario than the algorithm in comparison.

The Effects of Flutamide and Diethylstilbestrol Exposure on the Reproductive Organs and Thyroid of Male Rats by the Rodent 20-day Thyroid/Pubertal Assay

  • Moon, Hyun-Ju;Shin, Jae-Ho;Kim, Hyung-Sik;Lee, Su-Jung;Kang, Il-Hyun;Kim, Tae-Sung;Seok, Ji-Hyun;Kim, In-Young;Han, Soon-Young
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2002.10a
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    • pp.168-168
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    • 2002
  • To establish a test protocol for the rodent 20-day thyroid/pubertal assay, flutamide and diethylstilbestrol (DES) were administered to intact male Sprague-Dawley rats from postnatal day 33 for 20 days. Flutamide (1, 5, and 25 mg/kg/day) or DES (10, 20, and 40 ug/kg/day) was given once daily by oral gavage to immature male rats. Prepuce separation was significantly delayed in flutamide group and in DES group. One day after the last dose, the rats were killed and pituitary, thyroid, and reproductive organs were removed and weighed. Flutamide treatment resulted in a significant reduction in the weights of epididymides, ventral prostate, seminal vesicles plus coagulating glands and fluid (SVCGF), levator ani. bulbocarvenus muscles (LABC), Cowper's glands, and glans penis. The weight of adrenal glands decreased at % mg/kg/day, while testes and any other organ weights were unaffected. No microscopic changes were observed in the thyroid glands. Serum levels of testosterone wert significantly increased in the flutamide-treated groups and serum levels of estradiol were also increased. A significant reduction in the weights of testes, epididymides, ventral prostate, SVCGF, LABC, Cowpers glands, and glans penis of DES treated group. Serum testosterone and LH decreased significantly in DES group. Decrease of estradiol was observed, but not significant. These results indicate that flutamide and DES delay puberty in the male rat and its mode of action appears to be via altered secretion of steroids, which subsequently affect the development of the reproductive tract. (Supported by the grant from NITR/Korea FDA for Endocrine Disrupter Research.)

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A Numerical Study on the Wintertime Upwind flow of the Yellow Sen in an Idealized Basin

  • Kyung, Tae-Jung;Park, Chang-Wook;Oh, Im-Sang;Lee, Ho-Jin;Kang, Hyoun-Woo
    • Journal of the korean society of oceanography
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    • v.37 no.3
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    • pp.91-107
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    • 2002
  • The wintertime upwind flow in the Yellow Sea has been investigated through a series of two-dimensional numerical experiments in an idealized basin. A total of 10 experiments have been carried out to examine the effects of wind forcing, bottom friction and the presence of oceanic currents sweeping the shelf of the East China Sea. A spatially uniform steady and periodic wind stresses are considered along with comparison of linear and quadratic formulations. The wind-driven flow in the absence of oceanic current has been computed using Proudman open boundary condition (POBC), while the wind-driven current in the presence of oceanic current has been computed using Flather’s radiation condition (FOBC). The oceanic currents to be prescribed at the open boundary have been simulated by specifying uniform sea level gradients across the Taiwan Strait and the eastern ECS shelf, Calculations show that, as seen in Lee et al. (2000), oceanic flow little penetrates into the Yellow Sea in the absence of wind forcing unless a unrealistically low rate of bottom frictional dissipation is assumed. Both steady and time-periodic wind stresses invoke the upwind flow along the central trough of the Yellow Sea, independently of the presence of the oceanic current. The presence of oceanic currents very marginally alters the north-south gradient of the sea surface elevation in the Yellow Sea. Changes in the intensity and direction of the wind-induced mean upwind flow are hardly noticeable in the Yellow Sea but are found to be significant near Cheju Island where the gradient is reduced and therewith contribution of Ekman transport increases. In case of steady wind forcing circulation patterns such as two gyres on the slope sides, a cyclonic gyre on the western slope and an anticyclonic gyre on the eastern slope persist and the upwind flow composes part of the cyclonic gyre in the Yellow Sea. While in case of the time-periodic wind stress the appearance and disappearance of the patterns are repeated according to the time variation of the wind stress and the upwind flow accordingly varies with phase delay, mostly intensifying near the time when the wind forcing is approximately near the middle of the decaying stage.

The Estrus Manifestation according to the Follicle Size and the Growth Phase after $PGF_{2{\alpha}}$ Injection in Korean Native Cows (한우에서 $PGF_{2{\alpha}}$ 투여 후 난포 크기 및 발달 과정에 따른 발정 증상의 발현)

  • Park, Chul-Ho;Ryu, Jae-Sun;Yu, Dae-Jung;Park, In-Chul;Kim, Jong-Taek;Suh, Guk-Hyun;Oh, Ki-Seok;Son, Chang-Ho
    • Journal of Embryo Transfer
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    • v.27 no.3
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    • pp.141-147
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    • 2012
  • This study was operated to establish induction using ultrasonography by estimating the relation of follicle size and estrus manifestation. Clinical estrus symptoms were observed 97.4% in cows and 87.5% in heifers when overall 55 cows were induced to estrus in a single dose of $PGF_{2{\alpha}}$ after verifying CL through ultrasonography, which means estrus hours among those 52 cows showing the clinical estrus symptoms were estimated 2.39 days on cows and for 2.37 days on heifers which showed no differences (p>0.05). The estrus manifestation hours according to the follicle size in cows didn't have any significance each other (p>0.05), though estrus hours was 54 hours (the shortest) with follicle size bigger than 10 mm and were made up within 69 hours. The estrus manifestation hours according to the follicle size in heifers didn't have any significance each other (p>0.05) and took around 42 hours (the shortest) with follicle size of 5mm (the smallest) and were made up within 66 hours. Follicles after $PGF_{2{\alpha}}$ injection were ovulated and assigned to many phases as follows; Group 1 (growing phase) - continuously growing into ovulation, Group 2 (growing and static phase) - delaying in growth after the growth of follicles, Group 3 (static and growing phase) - growing after growth delay, Group 4 (regressing and new growing phase) - the follicle is closed and a new follicle grows. In addition, the process of follicle development and estrus hours had no significance each other (p>0.05), though estrus manifestation hours in Group 1 and 2 was relatively short, and in Group 3 and 4 for a relatively long time. In the result of all above, the estrus manifestation hours after $PGF_{2{\alpha}}$ injection has no differences accoring to the follicle size in cows and heifers. Therefore, High pregnancy rate is obtained when practicing artificial insemination within 3 days in estrus or TAI in 72 to 80 hours after adminitrating $PGF_{2{\alpha}}$.

A Single Allocation Hub Network Design Model for Intermodal Freight Transportation (단일할당 복합운송 허브 네트워크 설계 모형 개발)

  • Kim, Dong-Gyu;Gang, Seong-Cheol;Park, Chang-Ho;Go, Seung-Yeong
    • Journal of Korean Society of Transportation
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    • v.27 no.1
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    • pp.129-141
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    • 2009
  • Intermodal freight transportation is defined as the movement of freight from origins to destinations by two or more transportation modes. When implemented in hub networks, it could enhance the efficiency of the networks because consolidated flows are transported by more suitable modes and technologies. In spite of this advantage, the intermodal hub network design problem has received limited attention in the literature partly because of the complex nature of the problem. This paper aims to develop an optimization model for designing intermodal hub networks with sin91e allocation strategy. The model takes into account various cost components of intermodal hub networks including transportation, stationary inventory, and service delay costs. Moreover, using transport frequency variables, it is capable of endogenously determining the transportation economies of scale achieved by consolidation of flows. As such, the model is able to realistically represent the characteristics of intermodal hub networks in practice. Since the model Is a complicated nonlinear integer programming problem, we perform model simplification based on the analytical study of the model, which could facilitate the development of solution algorithms in the future. We expect that this study contributes to the design of intermodal hub networks as well as to the assessment of existing logistics systems.

Copper Interconnection and Flip Chip Packaging Laboratory Activity for Microelectronics Manufacturing Engineers

  • Moon, Dae-Ho;Ha, Tae-Min;Kim, Boom-Soo;Han, Seung-Soo;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.431-432
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    • 2012
  • In the era of 20 nm scaled semiconductor volume manufacturing, Microelectronics Manufacturing Engineering Education is presented in this paper. The purpose of microelectronic engineering education is to educate engineers to work in the semiconductor industry; it is therefore should be considered even before than technology development. Three Microelectronics Manufacturing Engineering related courses are introduced, and how undergraduate students acquired hands-on experience on Microelectronics fabrication and manufacturing. Conventionally employed wire bonding was recognized as not only an additional parasitic source in high-frequency mobile applications due to the increased inductance caused from the wiring loop, but also a huddle for minimizing IC packaging footprint. To alleviate the concerns, chip bumping technologies such as flip chip bumping and pillar bumping have been suggested as promising chip assembly methods to provide high-density interconnects and lower signal propagation delay [1,2]. Aluminum as metal interconnecting material over the decades in integrated circuits (ICs) manufacturing has been rapidly replaced with copper in majority IC products. A single copper metal layer with various test patterns of lines and vias and $400{\mu}m$ by $400{\mu}m$ interconnected pads are formed. Mask M1 allows metal interconnection patterns on 4" wafers with AZ1512 positive tone photoresist, and Cu/TiN/Ti layers are wet etched in two steps. We employed WPR, a thick patternable negative photoresist, manufactured by JSR Corp., which is specifically developed as dielectric material for multi- chip packaging (MCP) and package-on-package (PoP). Spin-coating at 1,000 rpm, i-line UV exposure, and 1 hour curing at $110^{\circ}C$ allows about $25{\mu}m$ thick passivation layer before performing wafer level soldering. Conventional Si3N4 passivation between Cu and WPR layer using plasma CVD can be an optional. To practice the board level flip chip assembly, individual students draw their own fan-outs of 40 rectangle pads using Eagle CAD, a free PCB artwork EDA. Individuals then transfer the test circuitry on a blank CCFL board followed by Cu etching and solder mask processes. Negative dry film resist (DFR), Accimage$^{(R)}$, manufactured by Kolon Industries, Inc., was used for solder resist for ball grid array (BGA). We demonstrated how Microelectronics Manufacturing Engineering education has been performed by presenting brief intermediate by-product from undergraduate and graduate students. Microelectronics Manufacturing Engineering, once again, is to educating engineers to actively work in the area of semiconductor manufacturing. Through one semester senior level hands-on laboratory course, participating students will have clearer understanding on microelectronics manufacturing and realized the importance of manufacturing yield in practice.

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Growth Characteristics and Nutritive Value of Chufa (Cyperus esculentus L.) for Forage Resource (사료자원으로서 Chufa (Gyperus esculentus L.)의 생장특성과 사료가치)

  • 이성규;황의경
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.22 no.1
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    • pp.1-8
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    • 2002
  • Chufa (Cyperus esculentus L.) belongs to one of the sedge family and pows well in summer. The aboveground part of chufa is mostly consisted of leaves and the underground part is mostly composed of a clump of fibrous root with tuber. At the seeding year, it does not reproductive development but produces a lot of tuber. It produced many tillers from the tuber and grows in clumps as a bunch type. The plant height of mature chufa was 73 to 75cm and it grown fully in the middle of July. The number of tillers were increased rapidly until the end of July and still increased slowly after August but it showed very poor growth. The final fresh weight and dry matter yield of aboveground part of chufa were 40.3 tou/ha and 12.1 tou/ha. respectively. The regrowth of aboveground part was vigorous in the early stage of growth after 1st cutting but it was decreased rapidly after the second cutting. In control plot, the number of tubers per a clump were 722 at final stage and their fresh and drymatter yields per m: were 4.2kg and 1.9kg, respectively. In experimental plots, the amount of tubers was decreased steadily according to delay of cutting date, but late cutting date was not affect the tuber formation severely because the tuber produced already early in August. The nutritive value of chufa in vegetative growth stage was good but it was decreased according to growing up. The contents of crude protein(CP), neutral detergent fiber(NDF), dry matter digestibility (DMD) and total digestible nutrients(TDN) of aboveground part of chufa harvested finally were 6.1%, 51.5%, 39.8%, 33.2% and 39.4%, respectively. The contents of crude protein(CP), neutral detergent fiber(NDF), dry matter digestibility(DMD) and total digestible nutrients(TDN) of tubers of chufa were 6.1%, 81.5%, 39.8%, 33.2% and 39.4%, respectively and the content of oil was as high as 16.2%, especially.