• Journal of ILASS-Korea
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• v.28 no.3
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• pp.150-155
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• 2023

Cold-start emissions are given great importance under the Euro-7 emission standard due to their significant impact on overall vehicle emissions. When an engine is started from a cold state, the combustion process is not yet optimized, leading to higher emissions. Hybrid vehicles, in particular, may face additional challenges, as their engine may remain inactive for extended periods, causing their catalysts to cool down and potentially become less effective in reducing emissions. In the present study, the performance of an electric heater was investigated as a means to enhance the catalyst heating during the start-up time. A simulation tool was utilized to develop a model for the gasoline exhaust aftertreatment system. The result indicates that the heater was able to increase the three-way catalyst temperature to 500℃ in 4 s using 20 kW power. In addition, the implementation of a secondary air supply resulted in reduced temperature overshoot and improved conversion efficiencies.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.234-245
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• 2008

Yeonkyopaedok-san(YPS) extract is widely used to treat the common cold. The purpose of this study was to evaluate the efficacy of YPS on the common cold. Two hundred Patients with common colds of recent onset were randomized to the double blind, placebo-controlled study. They received 800 mg YPS extract or placebo in capsules, orally dissolved 3 times a day for 7 days. The total symptom score was assessed by the physician, using a 5-point scale on start and finish. Resolution of cold symptoms based on subjective daily symptoms. Total symptom score was significantly decreased in YPS groups in comparison to that in placebo group (p=0.027). Headache (p=0.012), loss of appetite (p=0.037), eyeball discomfort (p=0.002) were more affected. Time to resolution of cold symptoms did not show significant effect (p=0.592). Adverse effects were less in the YPS group than placebo group (2% vs 3%). In this community-based, randomized controlled trial, YPS were effective in treating cold symptoms in college students.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.104-104
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• 2015

Due to the demand of the cold neutron flux in the neutron science and beam utilization technology, the cold neutron source (CNS) has been constructed and operating in the nuclear research reactor all over the world. The majority of the heat load removal scheme in the CNS is two-phase thermosiphon using the liquid hydrogen as a moderator. The CNS moderates thermal neutrons through a cryogenic moderator, liquid hydrogen, into cold neutrons with the generation of the nuclear heat load. The liquid hydrogen in a moderator cell is evaporated for the removal of the generated heat load from the neutron moderation and flows upward into a heat exchanger, where the hydrogen gas is liquefied by the cryogenic helium gas supplied from a helium refrigeration system. The liquefied hydrogen flows down to the moderator cell. To keep the required liquid hydrogen stable in the moderator cell, the CNS consists of an in-pool assembly (IPA) connected with the hydrogen system to handle the required hydrogen gas, the vacuum system to create the thermal insulation, and the helium refrigeration system to provide the cooling capacity. If one of systems is running out of order, the operating research reactor shall be tripped because the integrity of the CNS-IPA is not secured under the full power operation of the reactor. To prevent unscheduled reactor shutdown during a long time because the research reactor has been operating with the multi-purposes, the introduction of the standby cooling system (STS) can be a solution. In this presentation, the design considerations are considered how to design the STS satisfied with the following objectives: (a) to keep the moderator cell less than 350 K during the full power operation of the reactor under loss of the vacuum, loss of the cooling power, loss of common electrical power, or loss of instrument air cases; (b) to circulate smoothly helium gas in the STS circulation loop; (c) to re-start-up the reactor within 1 hour after its trip to avoid the Xenon build-up because more than certain concentration of Xenon makes that the reactor cannot start-up again; (d) to minimize the possibility of the hydrogen-oxygen reaction in the hydrogen boundary.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.5
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• pp.1163-1185
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• 2024

With the sharp increase in the volume of literature data, researchers must spend considerable time and energy locating desired papers. A paper recommendation is the means necessary to solve this problem. Unfortunately, the large amount of data combined with sparsity makes personalizing papers challenging. Traditional matrix decomposition models have cold-start issues. Most overlook the importance of information and fail to consider the introduction of noise when using side information, resulting in unsatisfactory recommendations. This study proposes a paper recommendation method (PR-SLSMF) using document-level representation learning with citation-informed transformers (SPECTER) and low-rank and sparse matrix factorization; it uses SPECTER to learn paper content representation. The model calculates the similarity between papers and constructs a weighted heterogeneous information network (HIN), including citation and content similarity information. This method combines the LSMF method with HIN, effectively alleviating data sparsity and cold-start issues and avoiding topic drift. We validated the effectiveness of this method on two real datasets and the necessity of adding side information.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.4
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• pp.406-413
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• 1993

Among 2-dimensional coastal hydrodynamic finite element models time stepping ADCIRC and STEPM. and harmonic FUNDY and TEA models were compared in order to find out their characteristics and analyze ernr. General feasibility and capability of models were studied by comparing model results with an analytical solution on some reference points and L$_2$norm error in quarter annular domain where analytical solution can be obtained. According to these tests harmonic models FUNDY and TEA were nearly coinciding with analytical solutions and gave better results than time stepping models. STEPM was at least 5 times better than ADCIRC in L$_2$norm error test and it was 7 times worse than harmonic models. It was expected and concluded that these errors might come from phase lag due to cold start condition and nonlinear effect in basic equations of time stepping models.

• Journal of the Korean Society of Costume
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• v.6
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• pp.145-160
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• 1982

Wearing a clothes in human living is very rightful and reasonable things. And it's also the necessaries of living. So now, I want look around about origin of clothes from the prehistorical age, how they start and why they need to wear a clothes. As human culture is unknown origin, human clothes origin is also unknown origin, too. So many different people made unlike story about that, and it is very difficult to say correct birth of clothes. It must be reflection by a time, by a place, by a mankind, until this days, the history of human progress is $2,000,000{\sim}3,000,000$ years. And from after the "Old Adam" man understand what is shame and disgrace, so that made them cover of their private parts, also it is a motive of human clothes. Since after pass a long time, the earth has many changes as it were weather, and for take care of human body from cold, people start make clothes and it's a second object of wearing a clothes. And third object of wearing clothes is after opportunity of development human culture, people desire for an aesthetic sence and for full-fill that feeling they start make a beautiful clothes with accessories and it is motive and a purpose of a human start wear a clothes. So I can say, for origin birth of clothes is 1. Protect of human body. 1) be adapted for different weather and different circumstance. 2) take care self from outside injurg. 2. Decorate for aesthetic sence. 1) Theory of Amulets. 2) Theory of symbolism. 3) Theory of Sex attraction. 4) Aesthetic Theory. 5) Theory of chastity. 6) Multi-theory And material for clothes they made from natural wilds like leaves, fur, skin of wood. skin of fishes and feather etc. But after develop of human knowledge people invent fiber, and use a knitted goods and woven stuff also first of all. They start use those kind that they just cover of their private parts as a belt and astring with leaves and a beast skins. But until this days it's taken big development with human knowledge and most important influence of develop was weather. So modern clothes for present days, must care with. physicology, preservation of health, living activity, dressing, morals, and etiquette etc.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.5
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• pp.568-576
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• 2017

With an increase in the usage of LNG, there is a heightened interest about its safety aspects regarding the explosion of LNG carrier tank. The need for a cryogenic explosion-proof camera has increased. The camera has to work in cryogenic environment (below $-160^{\circ}C$) in LNG carrier. This study conducted design and heat transfer analysis of cryogenic camera to secure working time in limitation of heat source. The design with gap width of double pane windows was conducted based on simple vertical cavity model to insulate from cryogenic environment. The optimal gap width was 12.5 mm. For effective analysis considering convection within the camera, equivalent thermal conductivity method was adopted with ABAQUS. The working time of the camera predicted was over 10 h at warm-start condition. In cold-start condition, it required about 5 h of pre-warming time to work. The results of analysis were compared with the ones of the actual cryogenic test.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.7-14
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• 2002

In order to reduce exhaust omissions of spark ignition engine, it is important not only to improve catalyst conversion efficiency but also to directly reduce engine out exhaust emissions, during cold starting and warm up process. Therefore many researchers have been attracted to develop an early fuel evaporator(EFE) by Introducing a ceramic heater fur a solution of engine out exhaust emissions in SI engine. But, the performance of the EFE in MPI engine to reduce the exhaust emissions and to improve the cold startability has not been clarified yet. The purpose of this study is to evaluate the feasibility of a glow plug far EFE. Impinging spray using heated and unheated glow plug helps the vaporization of the fuel and heat up the three way catalyst sufficiently. The amount of CO, and UHC is reduced overall. The amount of NOx is higher at the initial stage, but become lower as time goes on than without glow plug.

• The Korean Journal of Nuclear Medicine
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• v.20 no.1
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• pp.25-31
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• 1986

This study was performed to establish normal hepatoscintiangiographic(HSA) pattern of hepatic blood flow and to investigate dynamic differential HSA findings of primary and metastatic carcinomas and abscess of the liver. HSA was carried out after intravenous bolus injection of 10 mCi of Tc-99m-phytate by obtaining sequential anterior images of 1-second exposure for 16 seconds. Observations included (1) baseline study of normal hepatic blood flow pattern by correlating with contrast angiogram, (2) time sequence phasing of normal HSA, and (3) analysis of altered patterns in primary and metastatic carcinomas and abscesses of the liver. Materials consisted of 20 normal subjects, 28 primary hepatocellular carcinomas, 16 metastatic carcinomas and 7 liver abscesses. Results were: (1) Normal HSA demonstrated 3 distinct phases of arterialization(AP), of arterial hepatogram(AHP), and of portal venous hepatogram(PVHP). The means of each phase were 5.3, 6.3 and 8.3 seconds, respectively. Portal vein could be seen in all but one of 20 normal subjects. (2) Pattern changes in diseases groups were early start of AP in carcinomas and very early start of AP in abscesses. AP became prolonged in all disease group. (3) Distinction between AHP was sharp in metastasis and abscesses but un sharp in primary hepatoma. Cold area or areas became vascularized in primary hepatoma but not in abscess. Cold areas of metastasis were inhomogeneously vascularized in late AP and throughout AHP and became relatively vascular as PVHP began. The cold area of abscess showed rim enhancement during AH and APH. These differences in HSA pattern were very useful in differential diagnosis of the diseases studied.

• Journal of Intelligence and Information Systems
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• v.18 no.3
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• pp.13-34
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• 2012

The Paper Explores The Problem Of Recommending Talks To Attend At International Research Conferences. When Researchers Participate In Conferences, Finding Interesting Talks To Attend Is A Real Challenge. Given That Several Presentation Sessions And Social Activities Are Typically Held At A Time, And There Is Little Time To Analyze All Alternatives, It Is Easy To Miss Important Talks. In Addition, Compared With Recommendations Of Products Such As Movies, Books, Music, Etc. The Recipients Of Talk Recommendations (i.e. Conference Attendees) Already Formed Their Own Research Community On The Center Of The Conference Topics. Hence, Recommending Conference Talks Contains Highly Social Context. This Study Suggests That This Domain Would Be Suitable For Social Network-Based Recommendations. In Order To Find Out The Most Effective Recommendation Approach, Three Sources Of Information Were Explored For Talk Recommendation-Whateach Talk Is About (Content), Who Scheduled The Talks (Collaborative), And How The Users Are Connected Socially (Social). Using These Three Sources Of Information, This Paper Examined Several Direct And Hybrid Recommendation Algorithms To Help Users Find Interesting Talks More Easily. Using A Dataset Of A Conference Scheduling System, Conference Navigator, Multiple Approaches Ranging From Classic Content-Based And Collaborative Filtering Recommendations To Social Network-Based Recommendations Were Compared. As The Result, For Cold-Start Users Who Have Insufficient Number Of Items To Express Their Preferences, The Recommendations Based On Their Social Networks Generated The Best Suggestions.