Earticle

이번 연구에서 인삼의 약 배양을 통한 배 형성과 식물체의 재분화가 확인되었다. 인삼의 약 배양에서 캘러스 유도에 적합한 기본 배지는 MS 배지였고 sucrose 농도는 3%였으며, 배 형성에 적합한 호르몬 농도는 2,4-D 1.0 mg/L 또는 3.0 mg/L이었다. 저온 전처리에 의한 인삼 약 배양의 캘러스 유도와 배 형성의 효율성 차이는 확인할 수 없었다. 인삼의 품종별 약 배양의 효율성을 검정한 결과, 청선 품종의 배 형성률이 가장 우수하였으며 선운 품종은 배 형성이 관찰되지 않았다. 약 배양으로 유도된 캘러스의 배수성을 검정한 결과, 반수체 캘러스가 확인되었지만 이 캘러스에서 배는 형성되지 않았다. 약 배양 유래의 배를 발아배지에 치상하였을 때 정상적으로 식물체가 재분화 하였으며, 이 식물체의 배수성을 검정한 결과, 모두 2배체로 확인되었다. 추후 DNA 마커를 이용한 약 배양 유래 식물체의 동형접합성의 확인이 필요하다고 판단된다. 인삼 약 배양을 통하여 동형접합성 식물체를 생산할 수 있다면 인삼 육종 효율성을 증진시키는데 크게 기여할 수 있을 것이다.

Korean ginseng (Panax ginseng Meyer) is an economically important plant because of it is rich in saponins. It is mainly cultivated in Asia, including Korea and China. Since ginseng requires a long breeding period due to juvenility, homozygote production techniques, such as anther culture, must be urgently established. In the present study, callus induction and embryogenesis through anther culture were observed in P. ginseng. Murashige and Skoog medium was used as the basal medium suitable for callus induction. When the medium was supplemented with 3% sucrose, the callus induction rate was high and the callus size was large. Cold pretreatment did not significantly affect callus induction and embryogenesis. Embryogenesis was the most efficient when the embryo-formation medium was supplemented with 1.0 or 3.0 mg/L 2,4-dichlorophenoxyacetic acid. Cultivar significantly affected anther culture efficiency. Specifically, 'Cheongseon' showed the highest embryo-formation efficiency, whereas no embryogenesis occurred in 'Sunun'. Ploidy assessment revealed the haploid status of the induced calli. Embryos derived from anther culture formed shoots upon transfer to germination medium, although no difference in ploidy was noted between the induced callus and control. Overall, the anther culture conditions established in the present study may contribute to the production of homozygous P. ginseng plants in the future.

Metal-organic framework (MOF) is one of the representative porous materials composed of metal ions and organic linkers. In spite of many advantages of the MOFs such as high specific surface area and ease of structure control, drawbacks have become obstacles to the practical use of them with poor electrical conductivity and chemical stability. The ZIF-8, which is consisted of zinc and imidazole linker, is one of the solutions to improve the chemical stability issue. In addition, composites using the ZIF-8 and carbonbased materials are widely used to enhance the electrical conductivity. In this regard, supercapacitor is very attractive field for using the composites, because most of carbon-based materials are porous and conductive. Also, for sensor applications, the ZIF-8 composite is suitable material to meet the requirement in terms of the selectivity and sensitivity. This review summarizes recent progress of the composite materials with the ZIF-8 and the carbon-based materials for the supercapacitors and the chemical sensors. In particular, the composites are classified into ZIF-8-graphene, ZIF-8-carbon nanotube and ZIF-8-other carbon-based material.

This study aimed to identify characteristics of Generation MZ's consumer purchase decision journey to develop the new fashion CDJ model. The initial stage was affected by habit, online community, social media, aesthetics, circumstantial need, and proxy. In the search and consideration stage, mobile channels were used actively. In the active search and evaluation stage, online media, experiential data, and personal information were employed. In the purchase stage, zoomers took plenty of time in search and evaluation before spending, contrary to millennials who made their purchases more quickly. In the post-purchase experience stage, zoomers actively displayed follow-up behaviors depending on their satisfaction, such as retaining or deleting the app. While, millennials did not turn away from the store or brand, but followed up on their purchases even when they had an unsatisfactory experience. Based on the characteristics of CDJ, iterative cycle CDJ models were developed. Zoomers CDJ model was presented as a search loop that consists of the search and evaluation process, in which information accumulates, and a purchase loop in which the actual purchase occurs. The iterative cycle CDJ model was presented connected to the loyalty loop as the main section, which is accelerated in millennials' CDJ model.

전세계적으로 메타버스 산업이 부상함에 따라 국내에서도 관련된 국가 전략 및 육성 체계가 마련되었다. 정책의 복잡성이 증대됨에 따라 데이터 기반 정책 수립의 중요성은 더욱 커지고 있는 가운데 아직까지 메타버스 분야의 국가 R&D 동향을 진단하는 연구는 부족한 실정이다. 이에 본 논문은 2002년부터 2020년까지 추진된 9,651개 R&D 과제에 대한 NTIS의 국가 R&D 정보를 수집하여 현황을 살펴봄과 동시에 토픽 모델링에 기반하여 주요 주제를 식별하고 시계열적인 변화를 고찰하였다. 메타버스 분야 R&D 과제의 주요 토픽은 11개로 도출되었으며, 핫 토픽은 서비스·콘텐츠·플랫폼 개발 분야와 응용분야의 의료·수술 분야이었고, 콜드 토픽은 도시·환경·공간정보 분야였다. 정책 방향으로 전략적 R&D 관리와 메타버스 관련 법·제도 연구를 제안하였다.

With the rise of the metaverse industry worldwide, relevant national strategies and nurturing systems have been prepared in Korea. As the complexity of policies increases, the importance of establishing data-based policymkaing is growing, and studies diagnosing national R&D trends in the metaverse field are still lacking. Therefore, this paper collected NTIS national R&D information for 9,651 R&D projects promoted from 2002 to 2020. And this study looked at the current status and identified major topics based on the topic modeling, and considered time-series changes in the topics. Eleven major topics of R&D tasks in the metaverse field were derived, hot topics were service/content/platform development and medical/surgical fields of application fields, and cold topics were urban/environment/spatial information fields. Strategic R&D Management, metaverse-related laws, and institutional studies were proposed as policy directions.

본 연구에서는 중 2015 개정 교육과정에 따라 집필된 10권의 교과서를 대상으로 지속가능한 식생활교육과 관련된 내용의 교과서 분석을 실시하였으며, 교과서 분석 결과와 학생들의 요구도 조사를 바탕으로 6차시의 지속가능한 식생활교육 프로그램을 개발하였다. 개발된 프로그램은 영양교육 DESIGN 6단계의 절차를 이용했으며 ADDIE 모형 중 실행단계를 제외한 분석-설계-개발-평가 및 수정 단계를 거쳤다. 교과서 분석은 중학교「기술·가정1」3권, 중학교「기술·가정2」3권, 고등학교 「기술·가정」3권, 고등학교 「가정과학」교과서1권 총 10권을 이용하였으며 2015 개정 기술·가정 교육과정의 각론을 참고해 내용요소 중 지속가능한 식생활에 해당하는 범위로 한정하였다. 지속가능한 식생활 6차시 프로그램은 DESIGN 6단계 절차에 따라 지속가능한 식생활교육 프로그램과 교수전략, 매체 및 평가도구를 개발하였다. 1차시는 학생들이 자신의 현재 식습관 문제를 탐색하고 건강한 식습관으로 개선하기 위한 내용을 구성하였으며, 2차시는 영양성분표시에 대해 학습하고 3차시는 식품교환표를 활용해 자신의 1일 식단 구성하기, 4차시는 계절별 대표 작물의 이해와 푸드마일리지, 텃밭 체험, 5차시는 조리 시 지켜야 하는 안전수칙과 레시피 작성, 6차시는 조리 시 지켜야하는 안전수칙과 조리 실습으로 구성하였다. 개발된 프로그램은 전문가 검증을 받아 지속가능한 식생활을 통한 개인의 건강, 지역사회 및 지구환경의 부합성을 갖추도록 수정 및 보완되었다. 본 연구인 지속가능한 식생활교육 프로그램이 학생들의 생활 속에서 지속가능한 식생활을 실천하며 개인 건강과 지역사회, 지구환경에 도움이 되도록 활용되기를 기대한다.

The purpose of this study is to develop a sustainable dietary education program using garden vegetables for middle school students. Textbook analysis and demand survey were conducted before developing the program. Ten textbooks of technology and home economics for middle and high school students were analyzed and the results showed that none of the textbooks covered food gardening. Two hundred and six middle school students participated in the demand survey and the results revealed that students lack an understanding of food gardening despite high interest. Therefore, six sessions of a sustainable dietary education program using garden vegetables were developed based on a six-step DESIGN procedure. Then, the content validity of the program was evaluated by three experts and the program was revised based on the results. This dietary education program will lead students to live a sustainable diet, eventually benefiting the health and wellness of individuals, communities and ecosystems.

본 연구는 외부 요인을 모형에 강화시켜 암호화폐 수익률 예측력을 향상시키는 방법에 대해서 다루고 있다. 고려한 요인으로는 크게 나누어 금융 경제적 요인 및 심리적 요인을 고려하였다. 먼저 금융 경제적 요인을 반용하기 위해서 주성분 요인을 사용하여 수 많은 변수를 차원축소를 통해서 모형에 반영하였다. 또한 심리적 요인을 위해서는 뉴스 기사 데이터를 활용하여 산출해낸 감성지수를 활용하였다. 이러한 요인들은 충격반응함수 분석을 통해서 요인들의 의미와 영향력을 시각화하였다. 또한 전통적인 ARIMAX 뿐 만 아니라 랜덤포레스트 및 딥러닝 모형을 활용하여 비선형성을 반영하였다. 그 결과 요인 강화가 암호화폐 수익률 예측력을 향상시킴을 실증분석을 통해 밝혔으며 그 중에서 딥러닝 모형인 GRU가 가장 좋은 예측 성능을 보임을 관찰하였다.

In this study, we propose factor augmentation to improve forecasting power of cryptocurrency return. We consider financial and economic variables as well as psychological aspect for possible factors. To be more specific, financial and economic factors are obtained by applying principal factor analysis. Psychological factor is summarized by news sentiment analysis. We also visualize such factors through impulse response analysis. In the modeling perspective, we consider ARIMAX as the classical model, and random forest and deep learning to accommodate nonlinear features. As a result, we show that factor augmentation reduces prediction error and the GRU performed the best amongst all models considered.

In this study, a recovery coefficient (RC) calculation was conducted that can correct the underestimation of the standardized uptake value (SUV) due to the partial volume effect (PVE) through phantom measurements and formulas. The experiment was conducted using a dynamic phantom capable of implement cranio-caudal movement at a respiratory rate of 15 times per minute along with the measured phantom experiment of the stopped state, and the RC of the moving state is calculated and compared. Ingenuity TF (Philips Healthcare, Netherland) was used as a positron emission tomography/computed tomography (PET/CT) device. PET-CT Phantom (Biodex Medical System, USA) was used as a phantom for measurement. A phantom image in a stationary state was acquired, and a moving phantom image was acquired using the AZ-733V Respiratory Phantom (Anzai Medical Co, Japan) capable of breathing movement in the cranio-caudal direction under the same acquisition parameters. For RC calculation, the sphere maximum radioactivity concentration and the background mean radioactivity concentration of the acquired images were measured, and the initially determined sphere and background radioactivity concentrations were calculated. The calculated RC was 0.08 to 0.72. The size of sphere smaller, it was confirmed that the RC reduced. And the RC in the moving state reduced than in the stationary state. As a result of this study, the change of the RC was confirmed according to the size of spheres and the phantom moving. Using the RC derived by implement movement of breathing with the respiratory phantom, it is possible to considering correction of underestimated SUV by the partial volume effect of PET images and the patient movements.

최근 인공지능 주차관제시스템은 딥러닝을 활용해 차량 번호판에 대한 인식률을 높이고 있지만 위조번호판 부착 차량을 판별하지 못한다는 문제점이 있다. 이러한 보안상의 문제점이 있음에도 불구하고 현재까지 여러 기관에서 기존의 시스템을 그대로 사용하고 있는 상황이다. 실례로 위조번호판을 이용한 실험에서 정부의 주요 기관을 대상으로 진입에 성공한 사례도 있다. 본 논문에서는 이러한 위조번호판을 부착한 차량의 출입을 방지하기 위해서 기존 인공지능 주차관제시스템의 개선 방안을 제시한다. 이를 위해 제안하는 방법은 기존 시스템이 차량의 번호판의 일치여부를 통과기준으로 사용하듯이 이미지에서 특징이 되는 특징점의 정보를 추출해내는 ORB 알고리즘을 활용하여 추출한 차량 앞면 특징점들의 매칭 정도를 통과기준으로 사용하는 방법이다. 또한 내부에 차량이 존재하는지 여부를 확인하는 절차를 제안 시스템에 포함시켜 위조번호판을 부착한 동일 차종 차량의 진입도 방지하였다. 실험 결과, 위조번호판을 부착한 차량들의 진입을 막아내며 기존시스템에 비해 위조번호판을 막아내는 개선된 성능을 보였다. 이러한 결과를 통해 기존 인공지능 주차관제시스템의 체계를 유지하면서 본 논문에서 제안하는 방법들을 기존의 주차관제시스템에 적용하여 위조번호판을 부착한 차량의 출입을 방지할 수 있음을 확인할 수 있었다.

Recently, artificial intelligence parking control systems have increased the recognition rate of vehicle license plates using deep learning, but there is a problem that they cannot determine vehicles with fake license plates. Despite these security problems, several institutions have been using the existing system so far. For example, in an experiment using a counterfeit license plate, there are cases of successful entry into major government agencies. This paper proposes an improved system over the existing artificial intelligence parking control system to prevent vehicles with such fake license plates from entering. The proposed method is to use the degree of matching of the front feature points of the vehicle as a passing criterion using the ORB algorithm that extracts information on feature points characterized by an image, just as the existing system uses the matching of vehicle license plates as a passing criterion. In addition, a procedure for checking whether a vehicle exists inside was included in the proposed system to prevent the entry of the same type of vehicle with a fake license plate. As a result of the experiment, it showed the improved performance in identifying vehicles with fake license plates compared to the existing system. These results confirmed that the methods proposed in this paper could be applied to the existing parking control system while taking the flow of the original artificial intelligence parking control system to prevent vehicles with fake license plates from entering.

디젤엔진의 배출물 개선을 위해 탄소수가 낮은 천연가스를 혼합하여 사용하는 천연가스-디젤 혼소 연소가 각광받고 있다. 특히 자발화 특성에 차이가 있는 디젤과 천연가스의 특성을 이용한 반응성 제어 압축착화(reactivity controlled compression ignition, RCCI) 연소 전략을 통해 기존 디젤엔진의 효율과 배출가스를 동시에 개선시키는 연구가 활발하게 진행되어 왔다. 상사점보다 앞당겨진 디젤 직접 분사시기 적용을 통해 실린더 전체 영역의 균일 혼합기를 형성하여 전체적으로 희박한 자발화 기반 연소를 달성함으로써 질소산화물 (NOx) 및 입자상물질 (PM) 저감과 제동열효율 개선을 동시에 달성할 수 있다. 하지만 매우 희박한 저부하 영역에서 불완전 연소량이 증가하는 단점이 존재하며, 안정적인 연소 구현을 위해 디젤 분사시기가 민감하게 제어되어야 하는 어려움도 존재한다. 본 연구에서는 앞서 언급된 저부하 영역에서의 천연가스-디젤 혼소 엔진의 효율 및 배기 개선을 확인하고, 동시에 발전용 엔진 구동 영역에서 디젤 분사시기에 따른 연소안정성을 평가하였다. 실험에는 6 L급 상용디젤 엔진이 사용되었으며, 1,800 rpm, 50% 부하 영역 (~50 kW)에서 실험이 진행되었다. 제동효율 및 연소안정성을 개선하기 위한 전략으로 분무 패턴이 다른 2개의 인젝터를 적용하였으며, 천연가스/디젤 비율과 디젤 분사시기를 바꿔가면서 실험이 진행되었다. 실험 결과, 협각 분사가 추가된 수정 인젝터에서 제동 열효율이 증가하는 것을 확인하였다. 또한 연소안정성 및 출력, 그리고 강화된 배기 규제를 고려하였을 때 수정 인젝터의 분무 패턴이 예혼합연소 형성에 적합하였고 이를 통해 질소산화물 배출량을 Tier-V 기준치인 0.4 g/kWh 이하로 저감함으로써 RCCI 연소 가능 영역을 확장할 수 있음을 실험적으로 확인하였다.

In order to improve the emission of diesel engines, natural gas-diesel dual fuel combustion compression ignition engines are in the spotlight. In particular, a reactivity controlled compression ignition (RCCI) combustion strategy is investigated comprehensively due to its possibility to improve both efficiency and emissions. With advanced diesel direct injection timing earlier than TDC, it achieves spontaneous reaction with overall lean mixture from a homogeneous mixture in the entire cylinder area, reducing nitrogen oxides (NOx) and particulate matter (PM) and improving braking heat efficiency at the same time. However, there is a disadvantage in that the amount of incomplete combustion increases in a low load region with a relatively small amount of fuel-air. To solve this, sensitive control according to the diesel injection timing and fuel ratio is required. In this study, experiments were conducted to improve efficiency and exhaust emissions of the natural gas-diesel dual fuel engine at low load, and evaluate combustion stability according to the diesel injection timing at the operation point for power generation. A 6 L-class commercial diesel engine was used for the experiment which was conducted under a 50% load range (~50 kW) at 1,800 rpm. Two injectors with different spray patterns were applied to the experiment, and the fraction of natural gas and diesel injection timing were selected as main parameters. Based on the experimental results, it was confirmed that the brake thermal efficiency increased by up to 1.3%p in the modified injector with the narrow-angle injection added. In addition, the spray pattern of the modified injector was suitable for premixed combustion, increasing operable range in consideration of combustion instability, torque reduction, and emissions level under Tier-V level (0.4 g/kWh for NOx).

Natural colorants are regarded as substitutes for synthetic colorants in the fields of fiber dyeing, hair dyeing, cosmetic, and food industries. The use of natural colorants has been increased in view of global environment and sustainability. However, scientific approach to the production is required because the supply of natural colorants depends on the climate, soil, and cultivation methods. This brief review contains the advances in science and technology related to natural colorants including characterization, analysis, CIEL^*a^*b^* and Munsell color systems, and future prospects. For the characterization and the analysis of natural colorants, chromatography, some spectroscopic techniques (UV-Vis, FT-IR, NMR), mass spectrometry, and X-ray diffraction are generally used.

스타트업이 경제의 활력을 불어넣는 중요한 요소로 인식되며 각국은 경쟁력 있는 해외창업가와 스타트업을 자국 창업생태계에 유치하기 위해 치열하게 경쟁하고 있다. 이에 부응하듯 창업가들은 풍부한 가용 자원 및 창업 친화적인 환경을 따라 태어난 국가에 연연하지 않고 새로운 사업을 개척하기 위해 주저 없이 국경을 넘고 있는 현실이다. 이처럼 국가 간 창업 이주가 점차 빈번해지고 있음에도 불구하고, 이와 관련된 연구는 매우 드문 실정이다. 이러한 현실과 이론 연구의 간극을 보완하기 위해 본 연구는 스타트업의 국가 간 창업이주를 연구주제로 삼았다. 그리고 한국으로의 글로벌 창업 이주를 연구대상으로 선정하여 탐색적 연구를 진행하고 도출된 결과를 바탕으로 사회적 함의를 모색하고자 한다. 본 연구는 두 단계의 개별적 연구로 구성되어 있다. 첫 번째 단계는 글로벌 창업이주와 관련된 전문가의 의견을 수집하고 이주의 주요 요인을 찾기 위한 델파이 기법의 적용이다. 이는 국가 차원의 지역 창업생태계에 대한 선행 문헌조사를 바탕으로 전문가 인터뷰를 진행하고, 이를 통해 글로벌 기업 이주에 중요한 고유요인과 하위요인, 즉 창업이주의 요소를 도출하는 것을 목적으로 한다. 두 번째 단계는 AHP 모델을 이용한 중요도 측정이다. 중요도 측정은 한국으로 이주한 해외 창업가를 연구 표본으로 사용하여 글로벌 창업이주의 요인과 요소의 우선순위를 확인하였다. 본 연구의 결과는 몇 가지 흥미로운 사회적 함의를 제시한다. 첫째, 창업가의 글로벌 이주의 흐름 속에 유목민적 성향을 가진 창업자 집단이 발견되었다. 이들은 국내에 정착하기 전 이미 여러 다수의 국가에서 동일한 아이템으로 창업을 한 경험이 있다. 둘째, 글로벌 창업 이주의 맥락에서 중요한 고유요인과 요소가 존재했다. 창업 비자를 포함한 정부의 글로벌 창업 이주 지원정책 패키지가 좋은 예시이다. 셋째, 글로벌 창업자들이 국내로 창업이주를 결정할 때 영향을 미치는 요인들의 우선순위를 알 수 있었다. 본 연구는 최근 글로벌 창업생태계에서 주목을 받고있는 글로벌 창업이주라는 비교적 새로운 사회 현상을 중심으로 하여 선제적인 탐색 연구를 진행하였다는 점에서 의의를 찾을 수 있다. 하지만 국내로 이주한 글로벌 창업자들을 한정된 샘플로 이용하여 연구를 진행하였기에 본 연구를 통해 도출된 함의가 넓은 범위에서의 일반화가 어렵다는 한계점을 동시에 지니고 있다.

Startups are recognized as the vitality of the economy, and countries are competing to attract competitive overseas entrepreneurs and startups to their own startup ecosystem. In this global trend, entrepreneurs cross the border without hesitation, expecting abundant available resources and a startup friendly environment. Despite the increasing frequency of start-up migration between countries, studies related to this are very rare. Therefore, this study has chosen the cross-border migration of startups between countries as a research topic, and those who have been involved in the cross-border entrepreneurial migration to South Korea as a research sample. This study consists of two stages. The first research stage hires a Delphi method to collect expert opinions and find major factors related to the global startup migration. Drawing on the prior literature on the regional startup ecosystem at the national level, this stage is to conduct expert interviews in order to discover underlying factors and subfactors important for global migration of startups. The second stage measures the importance of the factors and subfactors using the AHP model. The priorities of factors and factors were identified hiring the overseas entrepreneurs who moved to Korea as the AHP survey samples. The results of this study suggest some interesting implications. First, a group of entrepreneurs with nomadic tendencies was found in the trend of global migration of entrepreneurs. They had already started their own businesses with the same business ideas in multiple countries before settling down in Korea. Second, important unique factors and subfactors in the context of global start-up migration were identified. A good example is the government's support package, including start-up visas. Third, it was possible to know the priority of the factors and subfactors that influence the global migration of startups This study is meaningful in that it preemptively conducted exploratory research focusing on a relatively new phenomenon of global startup migration, which recently catches attention in the global startup ecosystem. At the same time, it has a limitation in that it is difficult to generalize the meanings found in this study because the research was conducted based on the case of South Korea

In the rapidly changing era of knowledge revolution, user-centered IT services are emerging as a very important component of modern business. However, in order to lead IT services into success, traditional capabilities and competences are not good enough. Development of IT services involve service planners and designers as well as traditional systems developers. This detailed segmentation of job and corresponding competences among involved in IT service development brings in new type of conflicts and contradictions that may require special attention for IT services to be properly development and implemented. This study aims to explore and define competences and roles of newly emerging job groups in IT services: planners, designers, and developers. In order to identify underlying competences of these emergeing groups, two stage interviews were conducted. At the first stage, general competence framework is developed across these groups with different skills for similar competence catogories. Using the categories developed at the first stage, members of each groups were asked to rate and assess the competences of other groups. Comparisons of these reciprocal assessment revealed the conceptual differences and biases across these groups. Detail differences are discussed and implications are discussed.

Metal-organic frameworks (MOFs) are widely used in various fields because they make it easy to control porous structures according to combinations of metal ions and organic linkers. In addition, ZIF (zeolitic imidazolate framework), a type of MOF, is made up of transition metal ions such as Co²⁺ or Zn²⁺ and linkers such as imidazole or imidazole derivatives. ZIF-67, composed of Co²⁺ and 2-methyl imidazole, exhibits both chemical stability and catalytic activity. Recently, due to increasing need for energy technology and carbon-neutral policies, catalysis applications have attracted tremendous research attention. Moreover, demand is increasing for material development in the electrocatalytic water splitting and metal-air battery fields; there is also a need for bifunctional catalysts capable of both oxidation/reduction reactions. This review summarizes recent progress of bifunctional catalysts for electrocatalytic water splitting and metal-air batteries using ZIF-67. In particular, the field is classified into areas of thermal decomposition, introduction of heterogeneous elements, and complex formation with carbon-based materials or polyacrylonitrile. This review also focuses on synthetic methods and performance evaluation.

본 논문에서는 신축량이 크고 내구성이 우수한 모듈러 신축이음장치의 내진성능을 평가하기 위해 지진응답 거동해석과 지진거동모사실험을 수행하였다. 지진응답 거동해석은 한국(KS), 미국(AASHTO LRFD), 그리고 유럽(Eurocode)의 설계기준 응답스팩트럼을 적용하여 인공지진파를 생성하였다. 해석대상 교량은 경간 1,000m 사장교를 대상으로 각 기준에 대해 세가지의 인공지진파를 생성하였으며, 지진거동모사실험은 축방향과 횡방향의 동적 유압가력기를 사용하여 인공지진파를 재현하였다. 실험결과 축방향, 횡방향 및 양방향에 인공지진파를 재하하였을 때 신축이음의 거동 이상이나 파괴는 발생하지 않았으며, 신축이음장치의 지진거동에 대한 내구성 및 안전성을 확인하였다.

In order to evaluate the seismic performance of the modular expansion joint known for its large expansion allowance and remarkable durability, this study conducts seismic response analysis and seismic simulation test. The bridge selected for the seismic response analysis is a cable stayed bridge with main span length of 1,000m. Three artificial earthquake were generated with respect to the design response spectra of the Korean Standards (KS), AASHTO LRFD and Eurocode, and applied to the selected bridge. The seismic simulation tests reproduced the artificial earthquakes using dynamic hydraulic actuators in the longitudinal and transverse directions. The test results verified the durability and safety of the expansion joint in view of its seismic behavior since abnormal behavior or failure of the expansion joint was not observed when the artificial earthquake waves were applied in the longitudinal direction, transverse direction and both directions.

해운사는 화물수송을 통해 수입을 창출하며 그 수송의 근간이 되는 선박에 대한 투자의 의사결정이 그 무엇보다 중요하다. 그럼에도 불구하고 기존에는 모든 상황이 정태적으로 고정된 것으로 가정하는 경제성 분석 방법인 현금흐름할인법을 주로 활용하였다. 따라서 본 연구는 선박 투자의 비가역성과 편익의 불확실성을 고려하여 경제성 분석 시 실물옵션 모형이 유용함을 보여주는데 있다. 특히 본 연구는 실물옵션 중 이항옵션가격결정모형을 활용하였으며, A해운사의 실 투자자료를 활용하여 시뮬레이션을 진행하였다. 분석 결과, 현금흐름할인법 중 순현재가치법에 따른 중고선박의 투자가치는 음(-)으로 분석되었으나 의사결정의 유연성을 반영할 수 있는 이항옵션가격결정모형에서의 투자가치는 양(+)의 경제성이 있는 것으로 평가되었다. 또한 선박 투자의 경제성은 수익 변동성과 할인율에 영향을 받는 것으로 나타났다. 이에 해운사의 선박 투자의사 결정 시 기존 현금흐름할인법과 더불어 실물옵션 모형을 활용하면 보다 유연한 결정을 하는 데 도움이 될 것으로 판단된다.

Shipping companies earn profits through cargo transportation, and therefore, investment decisions to purchase ships are more important than anything else. Nevertheless, the cash flow discount method was mainly used in the economic analysis method, which assumes that all situations are static. This study shows that the real option model is useful in the economic analysis of ship investment. This economic analysis took into account the irreversibility of investment and uncertainty of benefits. In particular, this study used a binary option price determination model among real options. In addition, the simulation was conducted using actual investment data of A shipping company. As a result of the analysis, the investment value of used ships according to the net present value method was analyzed as negative (-), but the investment value in the real option model reflecting the flexibility of decision-making was evaluated as having positive (+) economic feasibility. It was analyzed that economic feasibility is affected by profit volatility and discount rate. Therefore, this study is expected to help shipping companies make more flexible decisions by using the real option model along with the existing net present value method when making ship investment decisions.

The financial MyData service has implemented in January 2022 and launched 45 services by banks, securities, credit cards and fintech companies. This study applied the Q methodology, to identify the user types of MyData services and compared the perceptions of employees of financial institutions who plan and develop the MyData services. There are three types of MyData service users: active users, limited users who focus on consumption and asset status inquiry, and sensitive users for personal information. There were two types of recognition of financial company employees. One is the active user support other is the sensitive user for personal information support. The analysis of subjective perceptions can be used as a reference for establishing a company's MyData service marketing strategy and establishing related policies to improve the MyData ecosystem.

In this study, the radiation dose rate was measured by time and distance and evaluated whether radiation dose rate was suitable for domestic and international discharge criteria. In addition, the radiation dose emitted from the patient was measured with a glass dosimeter to evaluate the exposure dose if the caregiver stays in the isolated ward by placing a humanoid phantom instead of the caregiver at a distance of 1 m from the patient, on the second day of treatment. After 23 hours of isolation, the radiation dose rates at a distance of 1 m were 20.54 ± 6.21 µSv/h at 2.96 GBq administration and 27.94 ± 12.33 µSv/h at 3.70 GBq administration. The radiation dose rates at a distance of 1 m were 25.90 ± 2.21 µSv/h when 2.96 GBq was administered and 34.22 ± 10.06 µSv/h when 3.70 GBq was administered after 18 hours of isolation. However, if the isolation period is short may cause unnecessary radiation exposure to the third person. The reading of the attached dosimeter from the morning of the second day of treatment until removal was 0.01 to 0.95 mSv, which is a surface dose determined by the International Commission on Radiation Units and Measurements. And the depth dose was 0.01 to 0.99 mSv. On the second day of treatment, even if the patient caregivers stayed in the isolation ward, the exposure dose of the patient family did not exceed the effective dose limit of 5 mSv recommended by the ICRP and NCRP.

A Kano model was used to classify the quality attributes of the service robot function for actual deployment that can support and replace bank employees. Quality attributes for a total of 6 dimensions and 23 service elements were divided into bank employees and customer groups, and service priorities were derived after comparative analysis. The Decision tree model was used to supplement the excessive simplification of quality attributes by the modest number of Kano models and to classify and predict by segment market. Of the 23 services, 16 were classified into the same attributes in both groups. 6 services classified as combination attributes used a Decision tree to identify differences in perception of quality attributes among groups. In terms of basic financial services and professional financial services, it was confirmed that bank employees feel financial service robots more attractive than ordinary customers. In the design of IT convergence service, we propose a methodology for deriving quality attributes by combining a Kano model for classifying quality attributes of two groups and a Decision tree for forecasting subdivision markets.

본 논문은 층간 보강재를 보강한 3D 프린팅 콘크리트의 부착강도를 평가하기 위해 수행되었다. 겹침이음 길이에 따라 두 종류의 층간 보강 방법을 고려하였다. 첫 번째 방법은 층간 보강재의 겹침이음을 하지 않았으며, 두 번째 방법은 40mm의 겹침이음을 고려하였다. 또한, 기건양생 조건과 수중양생 조건의 서로 다른 양생 조건을 고려하였다. 실험 변수를 고려하여 3D 프린팅 콘크리트 시편의 압축강도, 쪼갬인장강도 및 휨인장강도를 세가지 하중 방향에서 측정하였다. 압축강도, 쪼갬인장강도 및 휨인장 강도는 하중방향에 영향을 받았다. 특히 3D 프린팅으로 제작한 콘크리트 시편의 층간 부착면에 인장력이 작용하면 쪼갬인장강도 및 휨인장강도가 크게 감소하였다. 그러나 층간 보강재가 보강된 층의 종방향으로 하중이 가해질 때, 프린팅된 시편의 휨인장강도 또는 부착강도는 크게 증가하였다. 또한 기건양생 조건의 휨인장강도 또는 부착강도는 감소하였으며, 기건 양생 조건에 의해 더 많은 공극의 형성을 유발하여 하중에 더 취약해지는 것으로 나타났다.

This paper aims to evaluating the interlayer strength of 3D-printed concrete with interlayer reinforcement. According to lap splices, two reinforcement methods were considered. One method did not include lap splices of interlayer reinforcement, but the other method included lap splices with length of 40mm. In addition, two different curing conditions were applied: air curing conditions and water curing conditions. The compressive, splitting tensile, and flexural tensile strengths of 3D-printed concrete specimens were measured in three loading directions with different reinforcement methods and curing conditions. Splitting and flexural tensile strengths decreased considerably when tensile stresses acted over the interlayers of 3D-printed concrete specimens. However, the flexural tensile strength or interlayer bonding strength of the printed specimens increased significantly at the interlayers when the longitudinal interlayer reinforcement penetrated printed layers. Interlayer bonding strength of printed concrete decreased after air curing treatment was applied because interlayers of printed concrete with more pores formed by the air cu ring conditions are more vulnerable to the load.