• Journal of dental hygiene science
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• v.13 no.4
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• pp.434-439
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• 2013

This study was conducted to compare the dental plaque reduction using various mouthwashes with Quantitative Light induced Fluorescence-Digital (QLF-D). A survey on 20 students was carried out. The students who were at Shingu College. Experimental group was gargled 20 ml of Listerine during 30 seconds and 15 ml of Hexamedine during 60 seconds. Control group was gargled distilled water during 30 second. The data were analyzed with t-test using SPSS 20.0 program. The ratios of control group and experimental group were reduced. Degree of ${\Delta}R30$ and ${\Delta}R70$ Listerine group was a significant difference (p>0.05). Degree of Simple Plaque Score and ${\Delta}R30$ Hexamedine group was a significant difference (p>0.05). There was no significant difference in the distilled water gargle group (p<0.05). The result of this study has the effect of two mouthwashes reduced dental plaque. The evaluation data of this study will be used in clinical application and research about QLF-D.

• Food Science and Preservation
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• v.24 no.5
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• pp.593-599
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• 2017

The objective of this study was to investigate the effect of superheated steam (SHS) and high hydrostatic pressure (HHP) techniques on the improvement of the quality of Bulgogi product during manufacturing process. Bulgogi product was treated with four different cooking/treatment process: conventional cooking (CC), SHS cooking (SHS), CC and then HHP cooking (CC-HHP), and SHS and HHP cooking (SHS-HHP) samples. SHS treated product increased moisture content, and decreased crude protein. Additionally, hardness, gumminess and shear force values were significantly different among the samples (p<0.05). In safety experiment after 14 days of storage at refrigeration temperature indicated that the bacterial population was lower in the case of SHS-HHP as compared to CC-HHP. Changes in texture during the storage periods at $10^{\circ}C$ for SHS-HHP was lowest values with compared to the initial, while shear force values for both tended to decrease with increasing storage period. The TBA and VBN values for SHS-HHP increased to 0.48 ($5^{\circ}C$)-1.68 ($10^{\circ}C$) mg MD/kg and 25.14 ($5^{\circ}C$)-45.14 ($10^{\circ}C$) mg%, respectively after 15 days of storage. Overall, it was found that the combination of SHS and HHP reduced microbial growth, thus leading to improved product quality and sanitation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.321-326
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• 2002

Near infrared spectroscopy (NIR), is recently applied to analysis of food, and it gives non-destructive and highly reproducible results. The objectives of this study were to assay protein, lipid and starch content in Alaska pollack surimi and to investigate application in seafood. NIR spectra showed the absorbance signal at 1,510 nm, 2,050 nm, 2,170 nm and 2,180 nm for protein, and signal were increased with protein content. Standard error of equation (SEE) was 0,296 and standard error of prediction (SEP) was 0.327. In analysis of lipid in Alaska pollack surimi by NIR, near infrared spectra of lyophilized Alaska pollack surimi were scanned and the signals of absorbance from C-H functional groups in lipid were identified at 1,730 nm, 1,740 nm and 2,300 nm and these signals were risen as Increasing lipid contents of Alaska pollack surimi as samely protein. SEE and SEP were 0.319, 0,353, respectively. In starch analysis using NIR the signals of starch distinctly changed at wavelength of 1,450 nm and 1,950 nm. Collected values of SEE and SEP were 0.304 and 0.318, respectively and the range of errors was $0.0186\~0.6470$ in starch contents.

• Journal of Korean Society of Archives and Records Management
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• v.20 no.1
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• pp.115-137
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• 2020

This study aims to examine the limitations of status that describe archives based on the Archival rules, and to propose a new method using the Records in Context - Conceptual model (RiC-CM) as a solution. Given this, the study conducted literature reviews and case studies. The solutions based on RiC-CM and its effects on the limitations of the existing environment are as follows. First, RiC-CM can describe multiple provenances about archives. This can be solved by defining individual records and provenances as "entity" and expressing their associations as relationships. The interrelation of entities alone can more accurately represent the information of provenances associated with a particular archive, making it easier to identify the overall context that makes records. Second, RiC-CM can link related files. Those that belong to a specific records group (fonds) can be resolved by assigning them to individual entities and making interrelation according to the context that makes records. This method makes it possible to serve information about the context that makes records. From the user's point of view, more options are available for searching records. Third, RiC-CM can link all relevant producer-made records related to a specific production organization. If organizations are related to each other, they can be defined as "entity," and their relationship can be expressed as "associated with." It helps to comprehensively examine the context of provenances. The findings of this study are expected to be used as a basis for future research on RiC-CM, in response to the paradigm shift for electronic records management systems.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.244-245
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• 2003

고체나 액체 추진로켓에 비하여 하이브리드 추진 시스템은 작동조건의 안정성과 안전함등의 많은 장점을 가지고 있다. HTPB와 같은 고체연료는 제작 및 저장, 운송 그리고 장착상의 안정성을 가지고 있으며 하이브리드 로켓의 고체연료로의 산화제의 유입을 제어하면서 추력의 변화와 엔진내부의 연소중단과 재 점화를 용이하게 할 수 있다. 이러한 이유로 인하여 하이브리드 엔진은 좀 더 경제적인 장치로 기대를 모으고 있다. 그러나, 기존의 하이브리드 로켓 엔진은 고체 추진 로켓에 비하여 낮은 연료 regression 율과 연소효율을 가지는 단점이 있다. 이러한 단점을 해결하고 요구되어지는 추력값과 연료유량을 증가시키기 위하여 고체연료의 표면적을 증가시킬 필요가 있다. 기존의 하이브리드 엔진에서는 연료 그레인에 다수의 연소포트를 만들어 표면적을 증가시켰으나 이는 비 활용 공간의 증가와 추진제의 질량 및 체적분율의 상당한 감소를 초래한다. 지난 수십년간에 걸쳐 하이브리드 엔진에서 연료의 regression 특성 및 엔진 성능 향상을 위한 연구가 계속되어 왔으며 최근에 엔진의 체적 규제를 경감시키고 연료의 regression율을 향상시키기 위하여 선회유동을 이용하는 하이브리드 로켓 엔진들이 제안되고 있다. 이러한 선회유동을 가지는 하이브리드 로켓은 고체연료 그레인에 대하여 평행하게 유입되는 기존의 하이브리드 로켓에 비하여 고체연료 벽면에서의 대류열전달이 현저하게 증가하게 되어 아주 높은 고체연료의 regression율을 얻을 수 있는 이점이 있다. 선회유동 하이브리드 로켓의 연소과정은 고체 연료의 열분해과정, 대류 열전달, 난류 혼합, 난류와 화학반응의 상호작용, soot의 생성 및 산화과정, soot 입자 및 연소가스에 의한 복사 열전달, 연소장과 음향장의 상호작용 등의 복잡한 물리적 과정을 포함하고 있다. 이러한 물리적 과정 중 난류연소, 고체연료 벽면 근방에서의 대류 열전달 및 연소과정에서 생성되는 soot 입자로부터의 복사 열전달, 그리고 고체연료 열 분해시 표면반응들은 고체연료의 regression율에 큰 영향을 미친다. 특히 고체연료의 난류화염면의 위치와 폭, 그리고 비 예혼합 난류화염장에서 생성되는 soot의 체적분율의 예측은 난류연소모델, 열전달 모델, 그리고 regression율 모델에 의해 크게 영향을 받기 때문에 수치모델의 예측 능력 향상시키기 위하여 이러한 물리적 과정을 정확히 모델링해야 할 필요가 있다. 특히 vortex hybrid rocket내의 난류연소과정은 아래와 같은 Laminar Flamelet Model에 의해 모델링 하였다. 상세 화학반응 과정을 고려한 혼합분율 공간에서의 화염편의 화학종 및 에너지 보존 방정식은 다음과 같다. 화염편 방정식과 혼합분률과 scalar dissipation rate의 관계식을 이용하여 혼합분률과 scalar dissipation rate에 따른 모든 reactive scalar들을 구하게 된다. 이러한 화염편 방정식들을 mixture fraction space에서 이산화시켜서 얻은 비선형 대수방정식은 TWOPNT(Grcar, 1992)로 계산돼 flamelet Library에 저장되게 된다. 저장된 laminar flamelet library를 이용하여 난류화염장의 열역학 상태량 평균치는 presumed PDF approach에 의해 구해진다. 본 연구에서는 강한 선회유동을 가지는 Hybrid Rocket 연소장내의 난류와 화학반응의 상호작용을 분석하기 위하여 Laminar Flamelet Model, 화학평형모델, 그리고 Eddy Dissipation Model을 이용한 수치해석결과를 체계적으로 비교하였다. 또한 Laminar Flamelet Model과 state-of-art 물리모델들을 이용하여 선회 유동을 갖는 하이브리드 로켓 엔진의 연소 및 Soot 생성 및 산화과정을 살펴보았으며 복사 열전달이 고체 연료 표면의 regression율에 미치는 영향도 살펴보았다. 특히 swirl강도, 산화제의 유입위치 그리고 선회유동의 형성방식이 하이브리드 로켓의 연소특성 및 regression rate에 미치는 영향을 상세히 해석하였다.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.37-61
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• 2013

In modern international law, the absence of legal definition regarding drone(Unmanned Aerial Vehicle) has made legal scholars work on an typical analogy between aircraft codified in the international document and drone. The wording of the Convention on International Civil Aviation is limited to two categories of aircraft, such as civil aircraft and state aircraft, whereas military aircraft is not legally defined. As such it is, the current practices of the State regarding the drone flight over foreign territory have proven a hypothese that drone is being deemed as military aircraft. Principal usage of drone lies in reconnaissance and surveillance mission as well as so-called targeted killing, which is prohibited if the killing is treacherous. Claimed war against terrorism, however, is providing a legal rationale that targeted killing is not treacherous, and that the targeted person is not civilian but combatant. In such context, armed attack of drone is deemed legal and justified. Consequently, such attack is legal in the general context of the war. The rules that govern targeting do not turn on the type of weapon system used, and there is no prohibition under the laws of war on the use of technologically advanced weapons systems in armed conflict so long as they are employed in conformity with applicable laws of war. Drones may present interesting new challenges because of their sophistication and the technological advantage they convey to their operators.

• Management & Information Systems Review
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• v.39 no.1
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• pp.75-91
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• 2020

The purpose of this study is to examine the application of in-depth interviews in terms of exploration on the basis of the theoretical basis of various aspects of consumer empathy, and the question of whether the consumer can expand to the process of self empathy. Most studies related to consumer empathy divide the responsive dimension of consumer empathy into rational and emotional dimension based on empathy theory, and look at the empathic response perceived by consumers to the stimulus presented from the current point of view. In this study, however, we want to go one step further and confirm that the consumers themselves can ultimately go to the self-empathy stage by forming a creative street of reproduction and redevelopment. As a result of exploratory research through in-depth interviews, it was indirectly confirmed that consumer's empathetic response to specific marketing stimulus exists at the level of creative and self-empathetic as well as the emphasis of previous studies. Based on these findings, this study confirmed that consumer empathetic responses could go beyond a single dimension to form a multidimensional structure and move toward an expanded structure of empathic self-creation. This suggests that consumers' empathic responses should be grasped in terms of continuity of empathic responses rather than explained in a specific dimension. Although this study is meaningful as an early research of exploratory nature, it is necessary to supplement various content validity and refine the research method through subsequent studies. This study is expected to expand the understanding that consumer's empathy can be extended to other people's empathy and to be self-empathy.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.40-51
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• 1991

A Propeller design method using the newly developed blade section(KH18), which behaves better cavitation characteristics, is presented. Experimental results for two-dimensional foil sections show that the lift-drag curve and the cavitation-free bucket diagram of the new blade section are wider comparing to those of the existion NACA sections. This characteristic of the new section is particularly important for marine propeller applications since angle of attack variation of the propeller blade operating behind a non-uniform ship's wake is relatively large. A lifting surface theory is used for the design of a propeller with the developed section for a 2700 TEU container ship. Since the most suitable chordwise loading shape is not known a priori, chordwise loading shape is chosen as a design parameter. Five propellers with different chordwise loading shapes and different foil sections are designed and tested in the towing tank and cavitation tunnel at KRISO. It is observed by a series of extensive model tsets that the propeller(KP197) having the chordwise loading shape, which has less leading edge loading at the inner radii and more leading edge loading at the outer radii of 0.7 radius, has higher propulsive efficiency and better cavitation characteristics. The KP197 propeller shows 1% higher efficiency, 30% cavitation volume reduction and 9% reduction of fluctuating pressure level comparing to the propeller with an NACA section. More appreciable efficiency gain for the new blade section propeller would be expected by reduction of expanded blade area considering the better cavitation characteristics of the new blade section.

• Spatial Information Research
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• v.23 no.2
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• pp.49-57
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• 2015

Recently, Through the linkage and opening, the fusion of the spatial information, it is necessary for productive ecosystem to provide a variety of information and to increase the civil use. Depending on the economic growth, demand for quality of life and well-being has been on the increase. Spatial information service contents for the public convenience has emerged to solve the problem such as health, safety, welfare and discomfort of daily life This study aims to implement search services for a tailored residence space through the three-dimensional data modeling on cadastral information. To achieve this goal, we established the requirements for deriving a registered object by investigating recent trend with respect to existing cadastral data model and defined property and relationship. Focusing on Songpa-gu, Jamsil station in Seoul, we implemented search services for a tailored residence space for three-dimensional right analysis in conjunction with residential and commercial complex building. As a result, we derived a way to supply 3D cadastre information through open platforms (VWorld) and to represent efficiently, which is able to improve the quality of spatial information service contents for the public convenience as well as to widen utilization of information.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.75-85
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• 2020

The collection of biological data of indigenous species must comply with the Nagoya Protocol. Fungi contain various bioactive substances making them an attractive source of several products, including food and medicines. In this study, we investigated the growth characteristics of five indigenous fungal strains, Fomitiporia punctata, Polyporus ulleungus, P. brumalis, Gymnopus subnudus, and Tyromyces kmetii, isolated from samples collected in the Ulleungdo Island. The growth rates for each strain were assessed across various temperatures (20 ℃ to 35 ℃), culture media (Potato dextrose agar, Malt extract & Yeast extract agar, Malt extract agar, Malt extract & peptone agar, Sabouraud dextrose agar, and Modified Melin-Norkrans agar), and pH conditions (4.0 to 8.0). Additionally, we assessed the mycelial growth characteristics in liquid culture. The mycelial growth in different media varied across species; specifically, F. punctata (in MMNA), G subnudus (in MMNA), and P. brumalis (in MEPA) showed rapid growth. Optimal growth temperatures ranged between 25 ℃ and 30 ℃ for most species, with the exception of T. kmetii and P. brumalis, which were able to grow across all the temperatures tested. P. brumalis showed the best growth rate, whereas P. ulleungus showed the lowest growth potential. The optimal pH conditions for mycelial growth ranged between 4.0 and 5.0. In experiments using culture flasks, the dry weight of the culture filtrates decreased with the increasing incubation time and showed a significant decrease between 1 and 6 months of incubation, indicating that the five strains take longer than a month to fully use the culture media. Our findings highlight and establish the optimal growth conditions for five different fungal species that can be used in future application studies.