• 수산경영론집
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• 제51권4호
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• pp.47-67
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• 2020

I explore that South Korea's major import fishery product markets-frozen hairtail, frozen mackerel, frozen pollock and frozen squid-are integrated by testing whether there is favorable evidence of the law of one price (LOP). Unlike previous studies on the LOP for fishery product markets, I assume non-zero import costs and include them in a trade model. To explore whether LOP holds for major import fishery product markets in South Korea with non-zero import costs, I utilize a non-linear time-series model, Smooth Transition Autoregressive (STAR) model with the sample periods from January in 2002 to December in 2019. I find that the behaviors of home-foreign price (i.e., import price) differentials of all four major import fishery products are non-linear depending on whether trade occurs and favorable evidence of LOP for each import market in South Korea. These findings indicate that each of South Korea's major import fishery product markets is integrated. They imply that the supply of each major import fishery product-frozen hairtail, frozen pollock, frozen mackerel and frozen squid, and their prices are stable even if there is an economic shock on each market. When it comes to trade policy implications, the Korean trade policy including tariffs or quotas against their import countries for the four major import fishery products may not have influences on their price in the markets.

• 천문학회보
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• 제46권2호
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• pp.69.3-70
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• 2021

We present the chemical properties of star-forming dwarf galaxies (SFDGs) in five filamentary structures (Leo II A, Leo II B, Leo Minor, Canes Venatici, and Virgo III) around the Virgo cluster using the Sloan Digital Sky Survey optical spectroscopic data and Galaxy Evolution Explorer ultraviolet photometric data. We investigate the relationship between stellar mass, gas-phase metallicity, and specific star formation rate (sSFR) of SFDGs in the Virgo filaments in comparison to those in the Virgo cluster and field. We find that, at a given stellar mass, SFDGs in the Virgo filaments show lower metallicity and higher sSFR than those in the Virgo cluster on average. We observe that SFDGs in the Virgo III filament show enhanced metallicities and suppressed star formation activities comparable to those in the Virgo cluster, whereas SFDGs in the other four filaments exhibit similar properties to the field counterparts. Moreover, about half of the galaxies in the Virgo III filament are found to be morphologically transitional dwarf galaxies that are supposed to be on the way to transforming into quiescent dwarf early-type galaxies. Based on the analysis of the galaxy perturbation parameter, we propose that the local environment represented by the galaxy interactions might be responsible for the contrasting features in "chemical pre-processing" found in the Virgo filaments.

• 천문학회보
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• 제46권2호
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• pp.49.2-49.2
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• 2021

We present the results of long-term simultaneous monitoring observations (~ 12 years) of H²O (22 GHz) maser and several vibrationally excited lines of SiO J = 1-0, 2-1, 3-2 masers (43, 86, 129 GHz) carried out with the 21-m antennas of the Korean VLBI Network (KVN) toward a sample of three AGB stars (RT Vir, RR Aql, IRC-10151) that are believed to be semiregular variable star, Mira variable star, and OH/IR star, respectively, according to a sequential evolutionary phase of AGB star. A total 10 transitions were observed, of which we detected H²O, SiO 𝝊 = 1 and 2, J = 1-0, SiO 𝝊 = 1, J = 2-1 and J = 3-2 maser lines in all three target objects, depending on the observational epochs. In this study, we scrutinize the evolutionary traits of each target object based on the maser line profiles, flux/velocity variations, and phase lags with the optical light curves. The IRAS two color diagram and the infrared spectral energy distributions (SEDs) in the wavelength range from 1.2 to 240 ㎛ of three observed sources were also analyzed.

• 천문학회보
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• 제44권2호
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• pp.39.3-39.3
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• 2019

Ram pressure stripping due to the intracluster medium (ICM) is an important environmental process, which causes star formation quenching by effectively removing cold interstellar gas from galaxies in dense environments. The evidence of diffuse atomic gas stripping has been reported in several HI imaging studies. However, it is still under debate whether molecular gas (i.e., a more direct ingredient for star formation) can be also affected and/or stripped by ram pressure. The goal of this thesis is to understand the impact of ram pressure on the molecular gas content of cluster galaxies and hence star formation activity. To achieve this, we conducted a series of detailed studies on the molecular gas properties of three Virgo spiral galaxies with clear signs of active HI gas stripping (NGC 4330, NGC 4402, and NGC 4522) based on high-resolution CO data obtained from the Submillimeter Array (SMA) and Atacama Large Millimeter/submillimeter Array (ALMA). As a result, we find the evidence that the molecular gas disk also gets affected by ram pressure in similar ways as HI even well inside of the stellar disk. In addition, we detected extraplanar 13CO clumps in one of the sample, which is the first case ever reported in ram pressure stripped galaxies. By analyzing multi-wavelength data (e.g., Hα, UV, HI, and CO), we discuss detailed processes of how ram pressure affects star formation activities and hence evolution of cluster galaxies. We also discuss the origin of extraplanar 13CO, and how ram pressure can potentially contribute to the chemical evolution of the ICM.

• 한국프랜차이즈경영연구
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• 제15권2호
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• pp.77-87
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• 2024

Purpose: South Korea is one of the markets where diverse and innovative cuisines are being tried. Therefore, the expectations for Michelin star restaurants in South Korea are high. The expected value of a Michelin star restaurant consists of both hedonic and utilitarian aspects of the dining experience. These consumer expectations affect visit intention. Research design, data, and methodology: The survey period was from October 10, 2023 to October 18, 2023, and 302 copies were used for hypothesis verification. Result: Hedonic expected value was found to have a significant positive influence on short-term and long-term visit intention, but had no significant effect on mid-term visit intention. Utilitarian expected value was found to have a significant positive influence on short-term and mid-term visit intention, but did not appear to have a significant effect on long-term visit intentions. Short-term visit intention was found to have a significant positive influence on mid-term visit intention, and mid-term visit intention was found to have a significant positive influence on long-term visit intention. Conclusions: The theoretical implications are restaurants need to utilize third-party certification, such as the Michelin Guide. The practical implication is that Michelin star restaurants should provide expected value to increase short-term visit intention.

• Molecules and Cells
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• 제27권5호
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• pp.577-582
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• 2009

The development of a high-throughput functional genomic screening provides a novel and expeditious approach in identifying critical genes involved in specific biological processes. Here we describe a cell-based cDNA screening system to identify the transcription activators of BiP, an endoplasmic reticulum (ER) chaperone protein. BiP promoter contains the ER stress element which is commonly present in the genes involved in unfolded protein response (UPR) that regulates protein secretion in cells. Therefore, the positive regulators of BiP may also be utilized to improve the recombinant protein production through modulation of UPR. Four BiP activators, including human UDP-glucose:glycoprotein glucosyltransferase 1 (HUGT1), are identified by the cDNA screening. Overexpression of HUGT1 leads to a significant increase in the production of recombinant erythropoietin, interferon ${\gamma}$, and monoclonal antibody in HEK293 cells. Our results demonstrate that the cDNA screening for BiP activators may be effective to identify the novel BiP regulators and HUGT1 may serve as an ideal target gene for improving the recombinant protein production in mammalian cells.

• 컴퓨터교육학회논문지
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• 제17권2호
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• pp.115-124
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• 2014

하이퍼큐브와 스타 그래프는 상호연결망으로 널리 알려져 있다. 상호연결망의 임베딩은 임의의 연결망 G를 다른 연결망 H에 사상하는 것이다. 상호연결망 G가 H에 적은 비용으로 임베딩 가능하다는 것은 연결망 G에서 개발된 알고리즘들을 연결망 H에서 효율적으로 이용할 수 있는 장점이 있다. 본 논문에서는 HCN과 HON 사이의 임베딩과 스타(star)그래프와 하프팬케익그래프 사이의 임베딩을 분석한다. 연구 결과로 HCN(n,n)은 HON($C_{n+1},C_{n+1}$)에 연장율 3에 임베딩 가능하고, HON($C_d,C_d$)를 HCN(2d-1,2d-1)에 임베딩 비용은 O(d)임을 보인다. 또한 스타그래프는 하프팬케익그래프에 연장율 11, 확장율 1에 임베딩 가능하고, 평균 연장율은 8이다. 본 연구 결과는 HCN 연결망과 스타그래프에서 이미 개발된 여러 가지 알고리즘을 HON 연결망과 하프팬케익그래프에서 효율적으로 이용할 수 있음을 의미한다.

• 천문학논총
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• 제27권4호
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• pp.243-248
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• 2012

Nearby spiral galaxies M101 and M81 are considered to have undergone a galaxy-galaxy interaction. M101 has experienced HI gas infall due to the interaction. With AKARI far-infrared (IR) photometric observations, we found regions with enhanced star forming activity, which are spatially close to regions affected by the interaction. In addition, the relation between the star formation rate (SFR) and the gas content for such regions shows a significant difference from typical spiral arm regions. We discuss possible explanations for star formation processes on a kiloparsec scale and the association with interaction-triggered star formation. We also observed the compact group of galaxies Stephan's Quintet (SQ) with the AKARI Far-infrared Surveyor (FIS). The SQ shows diffuse intergalactic medium (IGM) due to multiple collisions between the member galaxies and the IGM. The intruder galaxy NGC 7318b is currently colliding with the IGM and causes a large-scale shock. The 160 micron image clearly shows the structure along the shock ridge as seen in warm molecular hydrogen line emission and X-ray emission. The far-IR emission from the shocked region comes from the luminous [CII]$158{\mu}m$ line and cold dust (~ 20 K) that coexist with molecular hydrogen gas. Survival of dust grains is indispensable to form molecular hydrogen gas within the collision age (~ 5 Myr). At the stage of the dusty IGM environment, [CII] and $H_2$ lines rather than X-ray emission are powerful cooling channels to release the collision energy.

• 한국광학회지
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• 제23권6호
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• pp.269-273
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• 2012

배광 분포 제어가 용이한 높이 분할방식 반사컵 설계를 수행함에 있어서, 배광 설계시 배광 분포의 설계오차를 줄이기 위하여, LED 칩 표면상의 광량 분포 변화에 따른 반사컵의 배광 특성 변화 경향성을 파악하여 최적 설계에 적용하였다. LED 패키지의 반사컵을 높이에 따라 2단 분할하여 최적 설계한 결과, 교차형과 비교차형의 조합 설계를 통해서 최대 광도와 균일도를 조절하거나 암흑 영역을 없애는 등 다양한 기능성 설계가 가능했다.

• Advances in aircraft and spacecraft science
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• 제3권4호
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• pp.427-445
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• 2016

Star sensors are the attitude estimation sensors of the satellite orbiting in its path. It gives information to the control station on the earth about where the satellite is heading towards. It captures the images of a predetermined reference star. By comparing this image with that of the one captured from the earth, exact position of the satellite is determined. In the process of imaging, stray lights are eliminated from reaching the optic lens by the mechanical enclosures of the star sensors called Baffles. Research in space domain in the last few years is mainly focused on increased payload capacity and reduction in launch cost. In this paper, a star sensor baffle made of Aluminium is considered for the study. In order to minimize the component weight, material wastage and to improve the structural performance, an alternate material to Aluminium is investigated. Carbon Fiber Reinforced Polymer is found to be a better substitute in this regard. Design optimisation studies are carried out by adopting suitable design modifications like implementing an additional L-shaped flange, Upward flange projections, downward flange projections etc. A better configuration of the baffle, satisfying the design requirements and achieving manufacturing feasibility is attained. Geometrical modeling of the baffle is done by using UNIGRAPHICS-Nx7.5(R). Structural behavior of the baffle is analysed by FE analysis such as normal mode analysis, linear static analysis, and linear buckling analysis using MSC/PATRAN(R), MSC-NASTRAN(R) as the solver to validate the stiffness, strength and stability requirements respectively. Effect of the layup sequence and the fiber orientation angle of the composite layup on the stiffness are also studied.