• 한국항공우주학회지
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• 제32권9호
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• pp.103-113
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• 2004

위성은 조립 및 시험 완료 후 운반 및 발사 순간부터 임무 궤도로 진입할 때까지 발사체에 의한 정하중, 동하중 및 충격하중을 겪게 되며, 임무궤도에서 열진공, 복사 및 미세중력 환경하에 놓이게 되어 위성의 설계, 제작, 조립 및 시험 시 이들 발사환경과 우주환경을 고려하여 개발을 수행하여야 한다. 본 논문에서는 HAUSAT-1 피코위성의 구조 열해석과 설계 결과를 논의하고, 발사 과정과 우주에서 겪게 되는 환경을 모사한 발사환경 및 우주환경시험의 결과를 논의한다. HAUSAT-1 위성의 기계시스템은 인증 수준의 진동시험과 열진공시험 후에도 안정하다는 것을 확인하였다.

• 산업경영시스템학회지
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• 제43권3호
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• pp.68-76
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• 2020

In a series of recent launch tests, North Korea has been improving the firepower of its missiles that can target South Korea. North Korea's missiles and submarines are capable of threatening targets in South Korea and are likely faster and more covert than the systems previously seen in North Korea. The advanced threats require that ROK Navy should not only detect them earlier than ever but also response quicker than ever. In addition to increasing threats, the number of young man that can be enlisted for military service has been dramatically decreasing. To deal with these difficulty, ROK navy has been making various efforts to acquire a SMART warship having enhanced defense capability with fewer human resources. For quick response time with fewer operators, ROK Navy should improve the efficiency of systems and control tower mounted on the ship by promoting the Ship System Integration. Total Ship Computing Environment (TSCE) is a method of providing single computing environment for all ship systems. Though several years have passed since the first proposal of TSCE, limited information has been provided and domestic research on the TSCE is still in its infancy. In this paper, we apply TSCE with open architecture (OA) to solve the problems that ROK Navy is facing in order to meet the requirements for the SMART ship. We first review the level of Ship System Integration of both domestic and foreign ships. Then, based on analyses of integration demands for SMART warship, we apply real time OA to design architecture for TSCE from functional view and physical view. Simulation result shows that the proposed architecture has faster response time than the response time of the existing architecture and satisfies its design requirements.

• 한국식품저장유통학회지
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• 제17권6호
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• pp.800-806
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• 2010

천일염을 사용한 김치를 소재로 한 음료의 레시피를 개발하고자 하였다. 천일염으로 만든 김치를 첨가하여 제조한 음료에 대하여 감미료의 선호도는 올리고당 > 벌꿀 > 슈가파우더 > 설탕 > 아스파탐 > 배즙 순으로 나타났다. 관능검사로는 김치첨가음료의 색, 냄새 및 종합적 기호도의 3가지 항목으로 평가하였다. 종합적인 기호도 (Overall acceptance)측면에서 동치미 음료가 6.24점, 백김치음료가 6.00점, 배추김치음료가 5.76점 순으로 나타나 동치미음료가 백김치나 배추김치음료보다 더 좋은 관능검사 점수를 나타내었다. 천일염 김치 첨가량은 10%가 대조구와 차이가 없는 것으로 나타났으며 동치미 음료, 백김치음료, 배추김치음료 세 가지 모두에서 공통적으로 가장 적절한 것으로 조사되었다. 제조 후 상온에서 저장했을 경우 저장 시간의 경과에 따라 백김치나 동치미 음료, 배추김치음료 모두 각 관능검사 항목에 대한 관능평점은 저하되었다.

• 한국환경보건학회지
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• 제35권3호
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• pp.226-234
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• 2009

The main objective of this study was to evaluate the effects on shape and size, compressive strength, water absorption and heavy metals leaching with various weight mixing ratios in waste ash brick products using waste recycling MSWI(Municipal Solid Waste Incinerator) bottom ash, steel slag and waste building material. The manufacturing processes for the waste ash brick consist of screening, mixing, conveyor transmission, compaction.forming, and curing steps of raw materials. The weight mixing ratios of steel slag around bottom ash were adjusted within the ranges of 10% to 30%. The reported results show that the width and thickness of the manufactured waste ash brick could be satisfied with $90{\pm}2mm\;and\;57{\pm}2mm$, respectively which are K.S. standards of products qualities. And in case of length, only 20-Ba50Ss30, 20-Ba60Wb20 and 20-Ba50Wb30 for the mixing ratios could be satisfied with $190{\pm}2mm$ that is K.S. standards of products quality. The compressive strength and water absorption for 20-Ba50Ss30 and 20-Ba70Wb10 were over $8N/mm^2$ and below 15% respectively that are K.S. standards of manufactured waste ash brick. The results of tests for the heavy metals leaching in the all manufactured waste ash bricks are also passed to the wastes management regulations. The cost analysis of 20-Ba50Ss30 is evaluated. The manufacturing cost is evaluated 34.3 won/brick with 8 hours and 20tons of raw material per day. Incinerators with problems in bottom ash disposal can therefore derive significant benefits from the application of waste ash brick production.

• 한국습지학회지
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• 제12권2호
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• pp.67-73
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• 2010

본 연구는 오염이 심한 유수지를 지속적으로 양호한 수질로 유지하기 위한 효율적 방안을 모색하고자 수행되었다. 유수지 수질을 양호하게 유지하려면 외부로부터 유입되는 비점오염원의 유입 차단이 필요하다. 본 연구에서는 이의 방안으로 다공성 슬래그의 활용을 제안하였다. 다공성 슬래그 넷트를 유수지에 설치하는 경우의 수질 변화를 알아보기 위하여 오염물질의 제거 정도를 실험하였다. 그 결과 접촉 시간과 인 제거 효율 간에는 높은 상관관계($r^2=0.9765$)를 나타내어 접촉시간이 처리효율에 미치는 중요한 인자임을 알 수 있었으며, 인과 부유물질은 조제 시료, 생물학적 처리수, 하수 모두 다공성 슬래그 충전상을 통과하면서 높은 효율로 제거됨을 확인할 수 있었다. 이로부터 비점오염원의 유입 방지를 위하여 유수지 수중 내부와 외부 호안에 다공성 슬래그 충전상의 설치방안을 제안하였다.

• 한국토양비료학회지
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• 제18권4호
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• pp.352-358
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• 1985

1~0.5mm모래로 충전(充塡)한 sand column을 통해서 Zeolite가 수직(垂直) 유실(流失)과 수리전도도의 변화(變化)에 미치는 양이온의 영향(影響)을 조사(調査)한 결과(結果)는 다음과 같다. 1. Zeolite의 유실량(流失量)의 정도(程度)는 Na->K->$NH_4-$ Zeolite 순이었고 Mg-과 Ca-Zeolite는 유실(流失)되지 않았다. 2. Zeolite의 수직유실(垂直流失)은 주로 입자(粒子)들의 분산(分散)에 기인(基因)하였으며 투과용액(透過溶液)이 0.01N 농도(濃度)의 염용액(鹽溶液)에서 증류수(蒸溜水)로 바뀔때 분산(分散)이 가장 잘 일어났다. 3. 수리전도도(水理傳導度)의 변화(變化)가 심한 column 일수록 Zeolite 유실량(流失量)이 많았다.

• The Journal of Advanced Prosthodontics
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• 제15권1호
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• pp.33-43
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• 2023

PURPOSE. This study investigated the physical and mechanical changes in the titanium base of three different hybrid abutment materials after cyclic loading by estimating the post-load reverse torque value (RTV), compressive side fulcrum wear pattern of titanium base, and surface roughness. MATERIALS AND METHODS. A total of 24 dental implants were divided into three groups (n = 8 each): Group Z, LD, and P used zirconia, lithium disilicate, and polyetheretherketone, respectively, for hybrid abutment fabrication. RTV was evaluated after cyclic loading with 50 N for 1.2 × 10⁶ chewing cycles. The compressive sides of the titanium bases were analyzed using a scanning electron microscope, and the roughness of the affected areas was measured using an optical profilometer after loading. Datasets were analyzed using Kruskal-Wallis test followed by Mann-Whitney tests with the Bonferroni correction (α = .05). RESULTS. Twenty-three samples passed the test; one LD sample fractured after 770,474 cycles. Post-load RTV varied significantly depending on the hybridabutment material (P = .020). Group P had a significantly higher median of post-load RTVs than group Z (16.5 and 14.3 Ncm, respectively). Groups LD and P showed minor signs of wear, and group Z showed a more pronounced wear pattern. While evaluating compressive side affected area roughness of titanium bases, lower medians were shown in group LD (Ra 0.16 and Rq 0.22 ㎛) and group P (Ra 0.16 and Rq 0.23 ㎛) than in group Z (Ra 0.26 and Rq 0.34 ㎛); significant differences were found only among the unaffected surface and group Z. CONCLUSION. The hybrid abutment material influences the post-load RTV. Group Z had a more pronounced wear pattern on the compressive side of titanium base; however, the surface roughness was not statistically different among the hybridabutment groups.

• 한국지반공학회논문집
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• 제24권4호
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• pp.15-21
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• 2008

본 연구에서는 3가지 조건(흙 / 해수 / 증류수)에 대해 3, 9, 18개월 동안 타설한 천연마섬유 배수재(NFD)로 인장 및 투수특성을 실시하여, 타설되지 않은 NFD와의 열화특성변화를 비교하여 보았다. 흙/필터 시험에 의한 투수계수는 무타설 배수재 필터시험의 투수계수보다 감소하였는데, 타설 시간이 경과됨에 따라 흙 타설 토조에서 배수재가 부패되어 투수시험시 점토분이 무타설 배수계보다 타설 배수재 필터에 쉽게 침투하여 섬유의 격자공간을 메워 발생하는 막힘 현상logging)이 심화되었기 때문이다. 타설기간 경과에 따른 배수재의 인장강도변화는 해수나 증류수 타설 배수계의 강도변화에 비해 흙 타설 배수계의 강도변화가 더 크게 나타났으며 특히 하절가의 강도저감이 동절기에 비하여 큰 것으로 나타났다.

• 한국BIM학회 논문집
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• 제13권3호
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• pp.21-29
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• 2023

ChatGPT, a chatbot based on GPT large language models, has gained immense popularity among the general public as well as domain professionals. To assess its proficiency in specialized fields, ChatGPT was tested on mainstream exams like the bar exam and medical licensing tests. This study evaluated ChatGPT's ability to answer questions related to Building Information Modeling (BIM) by testing it on Korea's BIM expertise exam, focusing primarily on multiple-choice problems. Both GPT-3.5 and GPT-4 were tested by prompting them to provide the correct answers to three years' worth of exams, totaling 150 questions. The results showed that both versions passed the test with average scores of 68 and 85, respectively. GPT-4 performed particularly well in categories related to 'BIM software' and 'Smart Construction technology'. However, it did not fare well in 'BIM applications'. Both versions were more proficient with short-answer choices than with sentence-length answers. Additionally, GPT-4 struggled with questions related to BIM policies and regulations specific to the Korean industry. Such limitations might be addressed by using tools like LangChain, which allow for feeding domain-specific documents to customize ChatGPT's responses. These advancements are anticipated to enhance ChatGPT's utility as a virtual assistant for BIM education and modeling automation.

• 한국의류학회지
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• 제40권5호
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• pp.921-935
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• 2016

This research analyzed the manual performance of firefighting protective gloves on global markets in order to suggest an evaluation method for firefighting protective gloves wearing comfort. We collected 13 types of firefighting gloves from domestic and international markets (7 types from Korea, 3 types form Europe, 2 types from the U.S and 1 type from Japan). We set the Don-Doff test as a basal requirement for moving toward to further manual performance tests that consist of: ASTM dexterity test, Minnesota dexterity test, Bennett hand tool test and ASTM torque test. All gloves were evaluated in dry and wet conditions, we included eight current male firefighters ($43.4{\pm}7.0yr$ in age, $173.1{\pm}4.4cm$ in height, $79.9{\pm}9.2kg$ in body mass) for the tests. Four gloves (1 Korea, 1 U.S, 1 Germany, and 1 Japan) out of thirteen firefighting gloves passed the Don-Doff test and had great subject preferences. There was no significant difference between dry and wet conditions on the ASTM dexterity test, Minnesota dexterity test, Bennett hand tool test and ASTM torque test. However, Japanese gloves had the greatest score and showed 3-4 times faster completion time on the ASTM dexterity test (p<.05), 1.2-1.5 times faster on the Minnesota dexterity test (p<.05), as fast as the bare hand on Bennett hand tool test (p<.05), and greater performance on the ASTM torque test compared to bare hand. In conclusion, Don-Doff test in wet conditions should be the first step for a mobility evaluation of domestic firefighting protective gloves; subsequently, a comprehensive test assorting ASTM, Minnesota, and Bennett test should be developed as a second step. The current ASTM torque test can be adopted as a third step. This three-step-method for evaluating firefighting protective glove mobility can be expected to expand into surveys of other safety gloves in Korea.