• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.99-103
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• 2011

Purpose: Head movement during brain perfusion SPECT (Diamox) scan is a one of important issues which decreases image quality. It also causes repeated scans. This study was designed to evaluate variable factors causing scan failures. Materials and Methods: 676 patients (359 men, 317 women, age average $54.5{\pm}18.4$) for brain perfusion SPECT (Diamox) scan from March, 2010 to Feb. 2011 were used as a subject. Age data and the kind of disease(Moyamoya disease (MMD), None moyamoya disease (NMMD), Cerebral infarction (CI)), test performance outcome (success,failure) were collected. The head movement factors(gender, disease, age, head fixation device) were evaluated by chi-square test and logistic regression analysis Results: The result showed that men had higher scan failure rate than women. Seniors in seventies(men 3.4%, women 1.5%) showed the most highest failure rate. Using head fixation device increased scan success rate up to 94.4~97.7%. The scan success rate is dependent upon gender, head fixation device by chi-square test(${\chi}^2$=3.8 (df=1, p<0.05), ${\chi}^2$=10.4 (df=1, p<0.001)) Gender, disease(CI), head fixation device showed very effective result in logistic regression analysis.(Wald=3.3 (p<0.07), Wald=3.7 (p<0.05), Wald=9.3 (p<0.05) Conclusion: It is demonstrated that gender, disease, using head fixation device is statistically very useful factors. Especially, head fixation device is a main key minimizing repeated scan.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.2
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• pp.97-103
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• 2004

This paper presents a general overview of the Korean stick-held dip net fishery for Pacific saury operated in the North Pacific Ocean since 1985. Annual catches, annual centroids distribution of fishing ground, and optimum fishing temperatures were compared between the periods before and after the new Korea-Japan bilateral fishery arrangement established in 1998. Fishing usually began in May and ended by December, during which major catches were taken in the months September~November before the bilateral fishery arrangement between Korea and Japan, whereas in August~October after the arrangement. It was observed that after the arrangement the centroids of fishing ground was shifted from the usual fishing area off the east coast of Japan to the east of South Kuril Islands, 45$^{\circ}$N and 151$^{\circ}$E. Optimum fishing temperatures appeared to be different by month ; 12.5~14.4$^{\circ}C$ in May, 12.0~14.2$^{\circ}C$ in June, 11.4~13.9$^{\circ}C$ in July, 11.4~15.9$^{\circ}C$ in August, 12.9~16.9$^{\circ}C$ in September, 12.7~17.3$^{\circ}C$ in October, 13.1~17.6$^{\circ}C$ in November, and 15.0~19.1$^{\circ}C$ in December. A total of 13 species were caught during scientific observation periods but the target species, Pacific saury, accounted for about 99.9% of the total catch. Although there was no difference in fishing days between those vessels equipped with the sonar and those without sonar, number of set, total catch, and CPUE of those with sonar were higher than those without sonar by 13%, 26%, and 12%, respectively.

• Journal of Applied Biological Chemistry
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• v.56 no.4
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• pp.229-234
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• 2013

Coal ash can be added to agricultural soils to increase the chemical properties of soil such as pH, cation exchange capacity and nutrient availability of - B, Ca, Mo etc-. Therefore, the main purpose of this study was to evaluate the feasibility of fly ash as a soil amendment in paddy soils. Selected fly ash was mixed with bentonite and calcium hydroxide at the ratio of 80:15:5 (w/w) and manufactured as a pellet type at the size of 10 mm. Field experiments were conducted to evaluate the effects of fly ash fertilizer on the soil quality and crop growth compare to the control (no fertilizer) and, - traditional fertilizer. Results showed that soil pH and organic matter in paddy soils after applying the manufactured fly ash fertilizer were not increased compared to the other two treatments. However, the concentration of available phosphate and silicate in paddy soils were higher than those of the control and traditional fertilization. With regard to crop growth, no significant difference was observed between three different treatments. However, the content of protein in the rice grain cultivated with the fly ash fertilizer was higher than in the rice cultivated by other two treatments. Overall, fly ash fertilizer could increase the concentration of available silicate and phosphate in the paddy soil and improve the rice quality. In conclusion, fly ash can be utilized in agricultural soils as soil amendment, especially in the rice paddy soil.

• Journal of the Korean Magnetics Society
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• v.26 no.5
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• pp.173-178
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• 2016

This study is to evaluate the effect of a Contrast Media (CM) on dose calculations and clinical significance in Radiation (Electromagnetic wave) Therapy (RT) plans for head & neck (H&N) and prostate cancer. Pinnacle 8.0 system was used to measure the change of Electron Density (ED) of the tissue for CM. To determine the effect of dose calculation due to CM, we did the RT planning for 30 patients. To compare the ED and dose calculations of RT plans, 3D CRT and IMRT plans were do with pinnacle and Tomotherapy planning system. Mean difference of ED between enhanced and unenhanced CT was less than 4%: H&N Target Volume (TV) 2.1%, parotid 1.9%, SMG 3.6%, tongue 0.9%, spinal cord 0.3%, esophagus 2.6%, mandible 0.1% and prostate TV 0.7%, lymph node 1.1%, bladder 1.2%, rectum 1.5%, small bowel 1.2%, colon 0.6%, penile bulb 0.8%, femoral head -0.2%. The dose difference between RT plan using CM and without CM showed an increase of dose in TV. The rate of increase was less than 2.5% (3D CRT: H&N 0.69~2.51%, prostate 0.04~1.14%, IMRT: H&N 0.58~1.31%, prostate 0.36~1.04%). RT plans using a CM has the insignificant effect on the organs and TV, so this error is allowable clinically. However, the much more accurate plan is possible as to image fusion (CM and without CM images) to ROI contour and when dose calculation, use the without CM image. Using the fusion of 'ROI import' perform calculations on without CM, it will be able to reduce the error (1~3%) caused by the CM.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.476-476
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• 2014

서론: 저 전력 소모를 필요로 하는 무선 센서 네트워크 관련 기술의 급격한 발달과 함께 자체 전력 수급을 위한 진동 에너지 수확 기술에 대한 연구가 활발히 이루어지고 있다. 다양한 구조와 소재를 압전 외팔보에 적용하여 제안하고 있다. 그 중에서도 진동 기반의 에너지 수확 소자는 주변 환경에서 쉽게 진동을 얻을 수 있고, 높은 에너지 밀도와 제작 방법이 간단하다는 장점을 가지고 있어 많은 분야에 응용 및 적용 가능하다. 기존 연구에서는 2차원적으로 진동 에너지 수확을 위한 휜 구조의 압전 외팔보를 제안 하였다. 휜 구조를 갖는 압전 외팔보는 각각의 짧은 두 개의 평평한 외팔보가 일렬로 연결된 것으로 볼 수 있다. 하나의 짧고 평평한 외팔보는 진동이 가해지면 접선 방향으로 응력이 생겨 최대 휨 모멘텀을 갖게 된다. 그러므로 휜 구조를 갖는 외팔보는 진동이 인가됨에 따라 길이 방향과 수직 방향으로 진동한다. 하지만, 이 구조는 수평 방향으로 가해지는 진동에 대한 에너지를 수확하기에는 한계점을 가진다. 즉, 3축 방향에서 임의의 방향에서 진동 에너지를 수확하기는 어렵다. 본 연구에서는 3축 방향에서 에너지를 효율적으로 수확할 수 있도록 헤어-셀 구조의 압전 외팔보 에너지 수확소자를 제안한다. 제안된 소자는 길이 방향과 수직 방향뿐만 아니라 수평 방향으로도 진동하여 임의의 방향에서 진동 에너지를 수확할 수 있다. 구성 및 공정: 제안하는 소자는 3축 방향에서 임의의 진동을 수확하기 위해서 길이를 길게 늘이고 길이 방향을 따라 휘어지는 구조의 헤어-셀 구조로 제작하였다. 외팔보의 구조는 외팔보의 폭 대비 길이의 비가 충분히 클 때, 추가적인 자유도를 얻을 수 있다. 그러므로 헤어-셀 구조의 에너지 수확 소자는 기본적인 길이 방향, 수직방향 그리고 수평방향에 더불어 추가적으로 뒤틀리는 방향을 통해서 3차원적으로 임의의 주변 진동 에너지를 수확하여 전기적인 에너지로 생성시킬 수 있다. 제작된 소자는 높은 종횡비를 갖는 무게 추($500{\times}15{\times}22{\mu}m3$)와 길이 방향으로 길게 휜 압전 외팔보($1000{\times}15{\times}1.7{\mu}m3$)로 구성되어있다. 공정 과정은 다음과 같다. 먼저, 실리콘 웨이퍼 위에 탄성층을 형성하기 위해 LPCVD SiNx를 $0.8{\mu}m$와 LTO $0.2{\mu}m$를 증착 후, 각각 $0.03{\mu}m$과 $0.12{\mu}m$의 두께를 갖는 Ti와 Pt을 하부 전극으로 스퍼터링한다. 그리고 Pb(Zr0.52Ti0.48)O3 박막을 $0.35{\mu}m$ 두께로 졸겔법을 이용하여 증착하고 상부 Pt층을 두께 $0.1{\mu}m$로 순차적으로 스퍼터링하여 형성한다. 상/하부 전극은 ICP(Inductively Coupled Plasma)를 이용해 건식 식각으로 패턴을 형성한다. PZT 층과 무게 추 사이의 보호막을 씌우기 위해 $0.2{\mu}m$의 Si3N4 박막이 PECVD 공정법으로 증착되고, RIE로 패턴을 형성된다. Ti/Au ($0.03/0.35{\mu}m$)이 E-beam으로 증착되고 lift-off를 통해서 패턴을 형성함으로써 전극 본딩을 위한 패드를 만든다. 초반에 형성한 실리콘 웨이퍼 위의 SiNx/LTO 층은 RIE로 외팔보 구조를 형성한다. 이후에 진행될 도금 공정을 위해서 희생층으로는 감광액이 사용되고, 씨드층으로는 Ti/Cu ($0.03/0.15{\mu}m$) 박막이 스퍼터링 된다. 도금 형성층을 위해 감광액을 패턴화하고, Ni0.8Fe0.2 ($22{\mu}m$)층으로 도금함으로써 외팔보 끝에 무게 추를 만든다. 마지막으로, 압전 외팔보 소자는 XeF2 식각법을 통해 제작된다. 제작된 소자는 소자의 여러 층 사이의 고유한 응력 차에 의해 휨 변형이 생긴다. 실험 방법 및 측정 결과: 제작된 소자의 성능을 확인하기 위하여 일정한 가속도 50 m/s2로 3축 방향에 따라 입력 주파수를 변화시키면서 출력 전압을 측정하였다. 먼저, 소자의 기본적인 공진 주파수를 얻기 위하여 수직 방향으로 진동을 인가하여 주파수를 변화시켰다. 그 때에 공진 주파수는 116 Hz를 가지며, 최대 출력 전압은 15 mV로 측정되었다. 3축 방향에서 진동 에너지 수확이 가능하다는 것을 확인하기 위하여 제작된 소자를 길이 방향과 수평 방향으로 가진기에 장착한 후, 기본 공진 주파수에서의 출력 전압을 측정하였다. 진동이 길이방향으로 가해졌을 때에는 33 mV, 수평방향으로 진동이 인가되는 경우에는 10 mV의 최대 출력 전압을 갖는다. 제안하는 소자가 수 mV의 적은 전압은 출력해내더라도 소자는 진동이 인가되는 각도에 영향 받지 않고, 3축 방향에서 진동 에너지를 수확하여 전기에너지로 얻을 수 있다. 결론: 제안된 소자는 3축 방향에서 진동 에너지를 수확할 수 있는 에너지 수확 소자를 제안하였다. 외팔보의 구조를 헤어-셀 구조로 길고 휘어지게 제작함으로써 기본적인 길이 방향, 수직방향 그리고 수평방향에 더불어 추가적으로 뒤틀리는 방향에서 출력 전압을 얻을 수 있다. 미소 전력원으로 실용적인 사용을 위해서 무게추가 더 무거워지고, PZT 박막이 더 두꺼워진다면 소자의 성능이 향상되어 높은 출력 전압을 얻을 수 있을 것이라 기대한다.

• Korean Journal of Construction Engineering and Management
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• v.16 no.3
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• pp.36-48
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• 2015

To complete various types of finish works with higher quality in much less time, TACT, which was mostly used for high-rise buildings, has been adapted to meet the needs for systematic schedule management in construction sites. However, the effectiveness of adapting TACT has not been shown as expected due to the different perspectives on productivity from both general contractor and subcontractors based on unforeseen conditions according to the types of site. Furthermore, not enough theoretical backgrounds, empirical data, and systematic approaches to solve the fundamental problems caused by each participants' different views on productivity has produced obstacles for establishing effective solutions. Therefore, this research aims to analyze the possible main reasons for having different point of views regarding productivity among various participants of residential building sites using TACT based on literature review, site survey, and interviews. Also, case study was conducted to propose obtainable productivity (OP) regression equation and productivity achievement ratio (PAR) with reduction factors (RFs) and actual productivity (AP) data from an actual construction site. The proposed outcome may assist general contractors converting output management with PPC to productivity management with actual data using PAR. On the other hand, subcontractors would be able to estimate theory-based maximum productivity of construction sites with TACT by using OP. The PAR will enhance the communication between general and sub-contractors for their decision making process. Finally, the main RFs derived from PAR could be used as essential keys for productivity management to increase the economical and operational effectiveness of the construction project.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.10-18
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• 2014

Purpose: Among different PET/CT devices which are composed of same PET model but different CT models, SUV, usually used for quantitative evaluation, was measured to assess the accuracy of follow up scans in different PET/CT and confirm that interequipment compatibility is useful in arranging the PET/CT exam appointment. Materials and Methods: Using ACR PET Phantom, PET NEMA IEC Body Phantom, SNM Chest Phantom and Ge-68 cylinder Phantom, $SUV_{mean}$ and $SUV_{max}$ was measured by 3 different models of PET/CT (Discovery 690, Discovery 690Elite and Discovery 710, GE) made in same company. ANOVA was used to evaluate the significant difference in the result. Results: In the result, the average of $SUV_{max}$ was D690 (25 mm-1.82, 16 mm-1.75, 12 mm-1.73, 8 mm-1.44), D690E (25 mm-1.76, 16 mm-1.92, 12 mm-1.78, 8 mm-1.55) and D710 (25 mm-1.84, 16 mm-1.89, 12 mm-1.77, 8 mm-1.61) in ACR Phantom, D690 (25 mm-2.26, 16 mm-2.25, 12 mm-1.92, 8 mm-1.85), D690E (25 mm-2.45, 16 mm-2.25, 12 mm-2.05 8 mm-1.91) and D710(25 mm-2.49, 16 mm-2.20, 1 2mm-2.30, 8 mm-2.05) in PET NEMA IEC Body Phantom, D690-1.04, D690E-1.10 and D710-1.09 in SNM Chest Phantom and D690-0.81, D690E-0.81, D710-0.84 in Ge-68 cylinder Phantom. The differences between average SUV of 4 phantoms were $SUV_{mean}$-1.87%, $SUV_{max}$-2.15%. And also as a result of ANOVA analysis, there was no significant difference statistically. Conclusion: If different models of PET/CT have same specification of PET system, there was no significant difference in $SUV_{mean}$ and $SUV_{max}$ even though they have different CT system. And also differences of $SUV_{mean}$ and $SUV_{max}$ in phantom images were under 5% which many manufacturers recommend. Therefore, follow up scan will be possible using different PET/CT if it has same specification of PET system with the previous PET/CT. This information will enable the accurate comparative analysis when conducting follow up scans and be helpful to schedule PET/CT exam more effectively.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.287-295
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• 2021

In this study, we aimed to evaluate the impact of different feed withdrawal periods (2, 3, 4, 5, and 6 h) on Salmonella contamination in the crop, intestinal weight, and blood parameters of broilers before harvesting. A total of 100 broilers (initial live weight 1.906±0.06 kg) were randomly assigned to the same five treatment groups and broilers had access to water but no feed before catching. Feed withdrawal times were 2, 3, 4, 5, and 6 h prior to slaughter. Measurements included live weight, pre-slaughter weight, carcass weight, weight of gastrointestinal tract. In addition, Salmonella and Campylobacter contamination in the crop, serum biochemical profiles, counts of leukocytes, erythrocytes, and platelets, and meat quality were assessed. The results demonstrate that carcass weight, blood corticosterone, meat pH, meat color, and water holding capacity did not differ based on the feed withdrawal time. Carcass yield increased as the withdrawal time increased, but the weights of the crop, proventriculus, jejunum, ileum, and rectum were significantly reduced by 6 h (P<0.05). Salmonella counts were the lowest in the crops subjected to 6 h of feed withdrawal (P<0.05). Shear force was highest in chicken breast meat after 6 h of feed withdrawal (P<0.05). However, when the feed was withdrawn after 6 h, the shear force increased, but it did not affect the sensory characteristics in consumers, and the Salmonella count also decreased and had a reduction effect on contamination during slaughter. These findings can serve as reference data for setting the feed withdrawal time.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.415-423
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• 2018

Rice panicle architecture is an important factor affecting yield potential. Korean rice cultivars have a narrow genetic background for panicle architecture. To enhance the yield potential of Korean rice cultivars, we developed and characterized rice lines with new panicle architecture. Rice with improved panicle architecture has clustered spikelets and dense panicles (CD type). CD rice was derived from a cross between "Binhae Col.#1" carrying dense panicles, and "ARC10319" that has the clustered spikelets gene (Cl). CD rice lines had short and semi-erect panicles with two to five high density spikelets clustered at the tips of primary and secondary rachis branches. CD rice lines had dramatically increased numbers of spikelets; almost twice as many as those of Korean rice cultivars. The increase in spikelet number was mainly caused by the increased spikelets and branches on secondary rachises compared to those on primary rachises. The increase in spikelet number was expected to enhance the yield of CD rice by expanding sink capacity. However, the yield of selected lines; CD9, CD27, CD34, and CD39, did not reach the level of the Korean high-yielding cultivars "Boramchan" and "Hanareum2," due to the reduction in panicle number and grain weight, and poor ripening. Although no substantial yield increase was observed in CD rice, the panicle architecture of CD rice, clustered spikelets, and dense panicles could be new genetic resources as breeding material for diversifying panicle architecture and enhancing yield potential.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.101-110
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• 2020

This study was conducted through the analysis of literature and on-site research as a case study of 14 artists' gardens with traditional themes presented at the garden fair. With Focusing on the design process for determining traditional reproduction, the following characteristics and implications were derived by analyzing the design goals, selection of subjects for traditional reenactment, determination of methods for reproduction, and design stages of landscape components. First, the pattern of selecting traditional structures as subjects for reproduction in many artist gardens can be understood as an advantage of being suitable for narrow sites and having remarkable topic communicability. They directly delivered the design intent by adding the names of traditional structures such as Madang, Wool, Buttumak, Jangdokdae, Chuibyeong and Seokgasan. Works expressed indirectly, such as Wall, Korean Garden, Suwon, and Seoul craftsmen, have relatively weak topic communicability. There were also symbolic representations of objects to be reproduced, such as Seonbi, marginal spaces, and Pung-lyu. Second, while reproducing Hanok Madang, separate the gardens paved with grass and stone, the fortress wall of Suwon Hwaseong and the northwest Gongsimdon of the watchtower. Also the garden with a miniature version of the extraneous Yong-yeon and the garden, which was reproduced as a low decorative wall in the rest area based on Nakan-Eupseong Fortress, shows the need for a deep understanding of tradition. On the other hand, the reproducting works of choosing the location of the traditional garden, the Korean Garden showed the importance of systematic arrangement with the surrounding environment, the beauty of the space in the courtyard of Hanok, the beauty of the slowness enjoyed by the scholars and the reenactments of the Pung-lyu culture of Moonlight boating are not only imitating traditional structures but also spreading understanding of tradition to garden culture and sentiment. Third, there were many works that reconstructed the real-size traditional structure in a straightforward way in relation to design. The garden was divided into Chuibyeong and the living space was decorated with Buttumak, chimneys, and gardens, and facilities representing Gyeongbokgung Palace, Soswaewon, and Seoseokji were systemically arranged. However it recognized the importance of selecting the key design elements, constructing the elevation of the structure, and the sense of scale of the space from works that reproduced the large Suwon Hwaseong and Nakan-Eupseong in an abstract way. While there are examples gardens of Hanok yards and Bazawul, which are far from the original image among the gardens that chose the dismantling method, the Blank-space garden expressed only by a frame composed of cubes, and Seonbi's Sarangbang garden, that permeated the moonlight with many traditional structures are the positive examples. The Seoul Artisan Garden, Jikji Simche Garden and Pung-lyu Garden, which display modernly designed landscape components, need an explanation to understand the author's intention.