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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016 (설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.6
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

Studies on Genetic Diversity and Phylogenetic Relationships of Korean Native Chicken using the Microsatellite Marker (Microsatellite Marker를 활용한 한국 토종닭 품종의 유전적 다양성 및 유연관계 분석)

  • Seo, Joo Hee;Oh, Jea-Don;Lee, Jun-Heon;Seo, Dongwon;Kong, Hong Sik
    • Korean Journal of Poultry Science
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    • v.42 no.1
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    • pp.15-26
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    • 2015
  • In this study, genotyping was executed by using 27 microsatellite markers for genetic diversity of 469 Korean Native Chickens [20 population, each population is 24 samples but Hanhyup A line is 13 samples). in total 469 samples were collected from National Institute of Animal Science (Korean Native Chicken (NR, NY, NG, NL and NW), Ogye (NO), Leghorn F,K (NF and NK), Black and Brown cormish (NH and NS), Rhode Island Red C, D (NC and ND), Total is 12 populations] and Hanhyup [H line (HH), F line (HF), G line (HG), V line (HV), S line (HS), W line (HW), Y line (HY), A line (HA), total is 8 populations]. [The allele number were observed 5 (ADL0268) to 20 (MCW0127) each markers. Observed heterozygostiy ($H_{obs}$), expected heterozygosity ($H_{exp}$), polymorphism Information Content (PIC) were observed 0.359 to 0.677, 0.668 to 0.881 and 0.646 to 0.869, respectively. Using these markers, the calculated the heterozygote deficit within chicken line ($F_{is}$) value each population from mean 0.117. Phylogenetic tree showing the genetic relationship among 20 population using standard genetic distance calculated from 27 microsatellite markers. genetic distances revealed the closest (0.175) between NC and ND. on the other hand, Farthest genetic distances (0.710) revealed between NF and HV. STRUCTURE analysis and Principal Components Analysis (PCA) showed that results of similar phylogenetic tree. The expected probability of identity values on random individuals (Total population and only Hanhyup line) was estimated at $8.80{\times}10^{-83}$ and $3.87{\times}10^{-117}$, respectively. In conclusion, This study shows the useful data that be utilized as a basic data of Korean Native Chicken breeding and development for commercial chicken industry to meet the consumer's demand.

A Study on the Intercity Mode Choice Behavior of Daegu Citizens According to the Introduction of Gyeongbu High-Speed Railway (경부 고속철도 개통에 따른 대구시민의 지역 간 통행수단 선택행태 분석에 관한 연구)

  • Yun, Dae-Sik;Yuk, Tae-Suk;Kim, Sang-Hwang
    • Journal of Korean Society of Transportation
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    • v.24 no.1 s.87
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    • pp.29-38
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    • 2006
  • After the first opening of the KTX in April 2004, travel time between major cities has been dramatically reduced. The reduction rates range from 32% to 47%. Considering travel time reduction between major cities, this study concerned about the intercity travel impact of the KTX operation. This study aimed to analyze intercity mode choice behavior of Daegu Citizens according to the first opening of the KTX. This study takes place in two sections. These are (i) the section of KTX between Daegu and Seoul, and (ii) the section of KTX between Daegu and Daejeon. This study estimated empirical models for analyzing intercity mode choice behavior according to the first opening of the KTX. This study makes use of the data from travel survey from Daegu metropolitan area. The main part of the survey was carried out in the KTX Dong-Daegu station. The survey data includes the information on travel from Daegu to Daejeon and from Daegu to Seoul. In order to analyze intercity choice behavior according to the frist opening of the KTX, multinomial model structure is used. For the model specification, a variety of behavioral assumptions about the factors which affect the mode choice, were considered. From the empirical model estimation, it is found that OVTT(Out-of-Vehicle Travel Time), OVTC(Out-of-Vehicle Travel Cost), IVTT(In-Vehicle Travel Time), IVTC(In-Vehicle Travel Cost), travel frequency, travel purpose, sex, age, occupation. household income, individual income are significant in choosing intercity travel mode. However, it is found that the intercity nde choice behavior is different between (i) the section of KTX between Daegu and Seoul, and (ii) the section of KTX between Daegu and Daejeon. Furthermore, some policy implications are discussed in conclusion.

The geography of external control in Korean manufacturing industry (한국제조업에서의 외부통제에 관한 공간적 분석)

  • ;Beck, Yeong-Ki
    • Journal of the Korean Geographical Society
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    • v.30 no.2
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    • pp.146-168
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    • 1995
  • problems involved in defining and identifying it. However, data on ownership of business establishments may be useful and one of the best alternatives for this empirical research because of use of limited information about control This study examines the spatial patterns of external control in the Korean manufacturing activities between 1986 and 1992. Using the data on ownership iinkages of multilocational firms between 15 administrative areas, it was possible to construct a matrix of organizational control in terms of the number of establishments. The control matrix was disaggregated by three types of manufacturing industries according to the capital and labor requirements of production processes used in. On the basis of the disaggregated control matrix, a series of measures were calculated for investigating the magnitude and direction of control as well as the external dependency. In the past decades Korean industrialization development has risen at a rapid pace, deepening integration into the world economy, together with the continuing growth of the large industrial firms. The expanded scale of large firms led to a spatial separation of production from control, Increasing branch plants in the nation. But recent important changes have occurred in the spatial organization of production by technological development, increasing international competition, and changing local labor markets. These changes have forced firms to reorganize their production structures, resulting in changes of the organizational structures in certain industries and regions. In this context the empirical analysis revealed the following principal trends. In general term, the geography of corporate control in Korea is marked by a twofold pattern of concentration and dispersion. The dominance of Seoul as a major command and control center has been evident over the period, though its overall share of allexternally controlled establishments has decreased from 88% to 79%. And the substantial amount of external control from Seoul has concentrated to the Kyongki and Southeast regions which are well-developed industrial areas. But Seoul's corporate ownership links tend to streteh across the country to the less-developed regions, most of which have shown a significant increase of external dependency during the period 1986-1992. At the same time, a geographic dispersion of corporate control is taking place as Kyongki province and Pusan are developing as new increasingly important command and control reaions. Though these two resions contain a number of branch plants controlled from other locations, they may be increasingly attractive as a headquarters location with increasing locally owned establishments. The geographical patterns of external control observable in each of three types of manufacturing industries were examined in order to distinguish the changing spatial structures of organizational control with respect to the characteristics of the production processes. Labor intensive manufacturing with unskilled iabor experienced the strongest external pressure from foreign competition and a lack of low cost labor. The high pressure expected not only to disinte-grate the production process but also led to location of production facilities in areas of cheap labor. The linkages of control between Seoul and the less-developed regions have slightly increased, while the external dependency of the industrialized regions might be reduced from the tendency of organizational disintegration. Capita1 intensive manufacturing operates under high entry and exit barriers due to capital intensity. The need to increase scale economies ied to an even stronger economic and spatial oncentration of control. The strong geographical oncentration of control might be influenced by orporate and organizational scale economies rather than by locational advantages. Other sectors experience with respect to branch plants of multilocational firms. The policy implications of the increase of external dependency in less-developed regions may be negative because of the very share of unskilled workers and lack of autonomy in decision making. The strong growth of the national economy and a scarcity of labor in core areas have been important factors in this regional decentralization of industries to less-developed regions. But the rather gloomy prospects of the economic growth in the near future could prevent the further industrialization of less-developed areas. A major rethinking of regional policy would have to take place towards a need for a regional policy actively favoring indigenous establishments.

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A Study on the Goal-Orientation of QI Performers in the Medical Centers (의료기관 QI 담당자의 목표추구몰입에 관한 연구)

  • Kim, Mi-Sook;Park, Jae-Sung
    • The Korean Journal of Health Service Management
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    • v.2 no.1
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    • pp.105-124
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    • 2008
  • The purpose of this research is to provide the data base for the activation of Quality Improvement operation through investigating the status of Quality Improvement operation, and finding out factors influencing on the goal-orientation of QI performers in the medical centers of more than one hundred beds where are practicing Quality Improvement operation. In order to reach the purpose, document study was carried out grounded on the proceeding researches and formulated statistical data in relation with the status of Quality Improvement performers, and proof study was carried out through questionnaire survey. The subjects of the survey were the Quality Improvement performers working in seventy three medical centers in Pusan-Gyeongnam, Daegu-Gyeongbuk, and Ulsan. Among eighty three Quality Improvement performers, fifty, five were questionnaire surveyed, on the result of which Reliability Analysis, Factor Analysis, and Multiple Regression Analysis were made, using statistical program. The the results of the proof analysis on this research are as follows. First, in the factors influencing the devoting to goal pursuit of QI performers, organization-goal contribution(0.44) had significant positive effects, while organization conflict(-0.25) had significant negative effects. In other words, the higher the organization-goal contribution was, the higher the devoting to goal pursuit was, while the less the organization conflict was, the higher the devoting to goal pursuit was, which was statistically significant.(p<0.05). Second, in the aspect of goal performance types of QI performers, the process-centered type showed high level of the devoting to goal pursuit, which was statistically significant.(p<0.05). Third, in the aspect of QI performance degree, the higher the devoting to goal pursuit was, the higher the QI performance degree was, which was statistically significant.(p<0.05). In addition, the performers who perceived their workplaces organic structure showed much higher QI performance degree, which statistically significant.(p<0.05). Generalizing the results of this research, it is possible to offer a few suggestions as follows. First, as the competition among the medical centers is more severe recently owing to medical center evaluation system, medical centers are practicing various Quality Improvement operation in all of medical services such as clinical performance and management performance, to reach the purpose of both cost-cutting and medical quality improvement. Thus in order to practice Quality Improvement operation more efficiently in medical centers, it is essential to nuke use of problem-solving methods and statistical members. This as the willingness of chief executives and positive attitude and recognition of organization members. This requires the installation of divisions in charge and disposition of persons in charge, not to speak of persistent training of Quality Improvement. Second, the divisions in charge of QI carry out Quality Improvement operation at the medical center level, and take the role of generalizing and adjusting QI performances of various departments. Owing to this role, the division in charge of QI is considered indispensable organization in the QI operation of medical centers along with medical QI committee, while it contributes to the government's goal of reducing quality level gaps among medical centers. Therefore it is necessary for government and QI organizations to give institutional support and resources for the sake of QI operation of medical centers, besides to supply systematic trainning and informations to the divisions and persons in charge of QI. Third, it is certain that disposition of persons in charge should be determined in view of the scale and the scope of QI operation in medical centers.

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A study on the Standardization of Design Guidelines for Geographic Information Databases (지리정보 DB 설계 지침의 표준화 연구)

  • Lim, Duk-Sung;Moon, Sang-Ho;Si, Jong-Ik;Hong, Bong-Hee
    • Journal of Korea Spatial Information System Society
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    • v.5 no.1 s.9
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    • pp.49-63
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    • 2003
  • Recently, two international standard organizations, ISO and OGC, have done the work of standardization for GIS. Current standardization work for providing interoperability among GIS DB focuses on the design of open interfaces. But, this work has not considered procedures and methods for designing GIS DB. Eventually, GIS DB has its own model. When we share the data by open interface among heterogeneous GIS DB, differences between models result in the loss of information. Our aim in this paper is to revise the design guidelines for geographic information databases in order to make consistent spatial data models, logical structures, and semantic structure of populated geographical databases. In details, we propose standard guidelines which convert ISO abstract schema into relation model, object-relation model, object-centered model, and geometry-centered model. Furthermore, we provide sample models for applying these guidelines in commercial GIS S/Ws. Building GIS DB based on design guidelines proposed in the paper has the following advantages: the interoperability among databases, the standardization of schema definitions, and the catalogue of GIS databases through.

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Inferring the Transit Trip Destination Zone of Smart Card User Using Trip Chain Structure (통행사슬 구조를 이용한 교통카드 이용자의 대중교통 통행종점 추정)

  • SHIN, Kangwon
    • Journal of Korean Society of Transportation
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    • v.34 no.5
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    • pp.437-448
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    • 2016
  • Some previous researches suggested a transit trip destination inference method by constructing trip chains with incomplete(missing destination) smart card dataset obtained on the entry fare control systems. To explore the feasibility of the transit trip destination inference method, the transit trip chains are constructed from the pre-paid smart card tagging data collected in Busan on October 2014 weekdays by tracing the card IDs, tagging times(boarding, alighting, transfer), and the trip linking distances between two consecutive transit trips in a daily sequences. Assuming that most trips in the transit trip chains are linked successively, the individual transit trip destination zones are inferred as the consecutive linking trip's origin zones. Applying the model to the complete trips with observed OD reveals that about 82% of the inferred trip destinations are the same as those of the observed trip destinations and the inference error defined as the difference in distance between the inferred and observed alighting stops is minimized when the trip linking distance is less than or equal to 0.5km. When applying the model to the incomplete trips with missing destinations, the overall destination missing rate decreases from 71.40% to 21.74% and approximately 77% of the destination missing trips are the single transit trips for which the destinations can not be inferable. In addition, the model remarkably reduces the destination missing rate of the multiple incomplete transit trips from 69.56% to 6.27%. Spearman's rank correlation and Chi-squared goodness-of-fit tests showed that the ranks for transit trips of each zone are not significantly affected by the inferred trips, but the transit trip distributions only using small complete trips are significantly different from those using complete and inferred trips. Therefore, it is concluded that the model should be applicable to derive a realistic transit trip patterns in cities with the incomplete smart card data.

A Study on Trust and Commitment between Buyer and Supplier of Industrial Parts, and Their Usage of Information Technology (산업재 부품 구매자와 공급자의 신뢰와 몰입, 그리고 정보기술의 이용에 관한 연구)

  • Kim, Jong-Hun;Yun, Hui-Taek
    • Proceedings of the Korean DIstribution Association Conference
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    • 2006.08a
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    • pp.47-68
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    • 2006
  • This study aims to determine the association structure of the behavioral relationship variables, such as trust, commitment, cooperation, communication and coercive power, in the relationship between the buyers and suppliers of industrial parts. It also investigates the impact of the use of IT technologies on the relationships quality. Data was collected from 216 part suppliers of machinery, electronics and automobiles located in Incheon. Data supported all of the proposed hypotheses. First, it was confirmed that parts suppliers' trust in buyers leads to the commitment into relationships with buyers. Second, cooperation and communication showed a positive influence on parts suppliers' trust in buyers, and coercive power gave a negative influence on trust. Third, the use of IT technologies like Internet and E-Mail between parts suppliers and buyers was verified to have generally a positive influence on the quality of relationships. At the same time, cooperation and communication were confirmed to have a positive influence on each other, and cooperation and coercive power as well as communication and coercive power were confirmed to have negative influence on each other. This study is a pioneering attempt to examine the relationships between suppliers and buyers of industrial parts, and the influence IT technologies on the relationship quality. Also, the findings will be practically much helpful to find how to reinforce the relationships between parts suppliers and buyers.

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Antecedents of Trust and Effects on Committment in B2B e-Marketplace (B2B 마켓플레이스에서 신뢰의 선행요인과 몰입에 미치는 영향)

  • Oh, Sang-Hyun;Kim, Sang-Hyeon
    • Journal of Distribution Research
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    • v.13 no.1
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    • pp.1-33
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    • 2008
  • As the interest in the business-to-business(B2B) electronic commerce is increasing, many companies are participating in the B2B e-Marketplaces. The e-Marketplace is defined as the virtual market that many players take part in to transact. The e-Marketplace has an influenced on the manner in which organizational buyers and sellers interact. As a result, it is important to develop an understanding of the behaviors of firms that use these electronic marketplaces. The purpose of this study is to develop a comprehensive model for trust and commitment of B2B e-Marketplace and empirically to examine their structural relationships. Drawing from trust and commitment theory in the interorganizational relationship and B2B electronic commerce context, this study identifies network externality, interactivity, justice, quality of information sharing, institutional assurance as the determinants of trust and commitment of e-Marketplace. The proposed model hypothesized that (1) trust is a function of network externality, interactivity, justice, quality of information sharing, institutional assurance, (2) attitudinal and behavioral commitment is a function of trust, (3) behavioral commitment is a function of attitudinal commitment. The proposed model is tested using organizational-level survey data from 187 buying organizations that conduct business in MRO e-Marketplaces. The data were tested by reliability test, correlation analysis, exploratory factor analysis, confirmatory factor analysis and covariance structure analysis. The results indicate that (1) trust is influenced by network externality, interactivity, justice, institutional assurance, (2) attitudinal commitment and behavioral commitment is influenced by trust (3) behavioral commitment is influenced by attitudinal commitment. Also, the empirical results confirmed that trust play a strong, central role in determinging e-Marketplace commitment. The key theoretical contribution of this research is that it begins to extend interorganizational information system literature in areas such as B2B Internet e-Marketplace. Managerially, this study contributes tn the understanding of the role of B2B e-Markeplace providers in Internet situation. And Limitations of this study and guidelines for future researches are also discussed.

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Empirical Forecast of Corotating Interacting Regions and Geomagnetic Storms Based on Coronal Hole Information (코로나 홀을 이용한 CIR과 지자기 폭풍의 경험적 예보 연구)

  • Lee, Ji-Hye;Moon, Yong-Jae;Choi, Yun-Hee;Yoo, Kye-Hwa
    • Journal of Astronomy and Space Sciences
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    • v.26 no.3
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    • pp.305-316
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    • 2009
  • In this study, we suggest an empirical forecast of CIR (Corotating Interaction Regions) and geomagnetic storm based on the information of coronal holes (CH). For this we used CH data obtained from He I $10830{\AA}$ maps at National Solar Observatory-Kitt Peak from January 1996 to November 2003 and the CIR and storm data that Choi et al. (2009) identified. Considering the relationship among coronal holes, CIRs, and geomagnetic storms (Choi et al. 2009), we propose the criteria for geoeffective coronal holes; the center of CH is located between $N40^{\circ}$ and $S40^{\circ}$ and between $E40^{\circ}$ and $W20^{\circ}$, and its area in percentage of solar hemispheric area is larger than the following areas: (1) case 1: 0.36%, (2) case 2: 0.66%, (3) case 3: 0.36% for 1996-2000, and 0.66% for 2001-2003. Then we present contingency tables between prediction and observation for three cases and their dependence on solar cycle phase. From the contingency tables, we determined several statistical parameters for forecast evaluation such as PODy (the probability of detection yes), FAR (the false alarm ratio), Bias (the ratio of "yes" predictions to "yes" observations) and CSI (critical success index). Considering the importance of PODy and CSI, we found that the best criterion is case 3; CH-CIR: PODy=0.77, FAR=0.66, Bias=2.28, CSI=0.30. CH-storm: PODy=0.81, FAR=0.84, Bias=5.00, CSI=0.16. It is also found that the parameters after the solar maximum are much better than those before the solar maximum. Our results show that the forecasting of CIR based on coronal hole information is meaningful but the forecast of goemagnetic storm is challenging.